A continuation of new experiments physico-mechanical, touching the spring and weight of the air and their effects. The I. part whereto is annext a short discourse of the atmospheres of consistent bodies / written by way of letter to the right honourable the Lord Clifford and Dungarvan by the honourable Robert Boyle ...
         Boyle, Robert, 1627-1691.
      
       
         
           1669
        
      
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         A28949
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         ESTC R34411
         14398415
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         102306
         
           
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             A continuation of new experiments physico-mechanical, touching the spring and weight of the air and their effects. The I. part whereto is annext a short discourse of the atmospheres of consistent bodies / written by way of letter to the right honourable the Lord Clifford and Dungarvan by the honourable Robert Boyle ...
             Boyle, Robert, 1627-1691.
          
           [24], 198, [11] p., 7 p. of plates : ill.
           
             Printed by Henry Hall ... for Richard Davis,
             Oxford :
             1669.
          
           
             Reproduction of original in the Huntington Library.
          
        
      
    
     
       
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         eng
      
       
         
           Air.
           Air-pump.
           Physics -- Experiments.
        
      
    
     
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           A
           CONTINVATION
           OF
           Nevv
           Experiments
           Physico-Mechanical
           ,
           Touching
           the
           SPRING
           and
           VVEIGHT
           of
           the
           AIR
           ,
           and
           their
           Effects
           .
        
         
           THE
           I.
           PART
           .
        
         
           Written
           by
           way
           of
           Letter
           ,
           to
           the
           Right
           Honourable
           the
           Lord
           Clifford
           and
           Dungarvan
           .
        
         
           VVhereto
           is
           annext
           a
           short
           Discourse
           Of
           the
           ATMOSPHERES
           of
           
             Consistent
             Bodies
          
           .
        
         
           By
           the
           Honourable
           ROBERT
           BOYLE
           ,
           Fellow
           of
           the
           
             Royal
             Society
          
           .
        
         
           OXFORD
           ,
           Printed
           by
           
             Henry
             Hall
          
           Printer
           to
           the
           University
           ,
           for
           
             Richard
             Davis
          
           ,
           in
           the
           Year
           1669.
           
        
      
       
         
         
         
           The
           PREFACE
           .
        
         
           HAving
           at
           the
           beginning
           of
           the
           Treatise
           ,
           whereof
           This
           is
           a
           Continuation
           ,
           acquainted
           my
           Readers
           with
           several
           things
           that
           belong
           in
           common
           as
           well
           to
           the
           following
           Experiments
           ,
           as
           to
           those
           There
           publish'd
           ;
           it
           will
           not
           be
           necessary
           for
           me
           to
           trouble
           the
           Reader
           with
           a
           repetition
           of
           what
           he
           may
           have
           met
           with
           there
           already
           ,
           nor
           to
           acquaint
           him
           in
           this
           Address
           with
           any
           Other
           particulars
           then
           Those
           that
           concern
           the
           Experiments
           I
           am
           now
           about
           to
           present
           him
           .
        
         
           I
           doubt
           not
           but
           it
           will
           be
           remembred
           by
           some
           ,
           that
           I
           seem'd
           in
           the
           above
           mentioned
           Book
           to
           have
           promis'd
           a
           Second
           part
           of
           it
           ,
           or
           a
           large
           Appendix
           to
           it
           :
           but
           Intimations
           of
           that
           kind
           do
           many
           times
           respect
           onely
           the
           Thing
           it self
           ,
           leaving
           the
           Giver
           of
           them
           free
           in
           point
           of
           Time
           :
           and
           I
           wanted
           not
           sufficient
           inducements
           to
           delay
           a
           while
           to
           perform
           my
           Promise
           ,
           if
           I
           made
           any
           .
           I
           had
           indeed
           ,
           partly
           before
           the
           Book
           already
           referr'd
           to
           came
           from
           the
           Press
           ,
           and
           partly
           sometime
           after
           ,
           made
           divers
           other
           Tryals
           in
           order
           to
           a
           Supplement
           of
           it
           :
           but
           being
           oblig'd
           to
           make
           some
           Journeys
           and
           Removes
           ,
           which
           allowed
           me
           no
           Opportunity
           to
           prosecute
           the
           Experiments
           ,
           I
           had
           made
           no
           very
           great
           Progres
           
           in
           my
           Design
           ,
           before
           the
           convening
           of
           an
           Illustrious
           Assembly
           of
           Virtuosi
           ,
           which
           has
           since
           made
           it self
           sufficiently
           known
           under
           the
           Title
           of
           the
           
             Royal
             Society
          
           .
           And
           having
           then
           thought
           fit
           to
           make
           a
           Present
           ,
           to
           persons
           so
           like
           to
           imploy
           it
           well
           ,
           of
           the
           great
           Engine
           ,
           I
           had
           till
           then
           made
           use
           of
           in
           the
           Physico-Mechanical
           Experiments
           about
           the
           Air
           ;
           and
           being
           unable
           afterwards
           to
           procure
           another
           so
           good
           ,
           I
           applied
           my
           Studies
           to
           other
           Subjects
           ,
           and
           gave
           over
           for
           a
           great
           while
           the
           care
           of
           making
           more
           Experiments
           of
           that
           kind
           :
           and
           the
           rather
           ,
           because
           that
           finding
           by
           the
           very
           favourable
           reception
           Those
           I
           had
           publish'd
           had
           met
           with
           among
           the
           Curious
           in
           several
           parts
           of
           Europe
           ,
           that
           they
           were
           like
           to
           be
           Considered
           and
           Perused
           ;
           I
           thought
           I
           might
           safely
           leave
           the
           Prosecution
           of
           them
           to
           Others
           ,
           who
           would
           probably
           come
           more
           Fresh
           and
           untired
           to
           such
           an
           Exercise
           of
           their
           Curiosity
           .
        
         
           But
           observing
           ,
           that
           the
           great
           Difficulties
           men
           met
           with
           in
           making
           an
           Engine
           ,
           that
           vvould
           exhaust
           and
           keep
           out
           a
           Body
           so
           subtle
           as
           the
           Air
           ,
           and
           so
           ponderous
           as
           the
           Atmosphere
           ,
           (
           besides
           perhaps
           some
           other
           impediments
           )
           vvere
           such
           ,
           that
           in
           five
           or
           six
           year
           I
           could
           hear
           but
           of
           one
           or
           two
           Engines
           that
           vvere
           brought
           to
           be
           fit
           to
           Work
           ,
           and
           of
           but
           one
           or
           two
           Nevv
           Experiments
           ,
           that
           had
           been
           added
           by
           the
           Ingenious
           Owners
           of
           Them
           ;
           I
           began
           to
           listen
           to
           the
           Perswasions
           of
           Those
           that
           suggested
           ,
           That
           unlesse
           I
           resum'd
           this
           work
           
           my self
           ,
           there
           would
           scarce
           be
           much
           done
           in
           it
           .
           And
           therefore
           having
           (
           by
           the
           help
           of
           Other
           work-men
           then
           Those
           I
           had
           unsuccesfully
           imploy'd
           before
           )
           procured
           a
           new
           Engine
           lesse
           than
           the
           Other
           ,
           and
           differing
           in
           some
           Circumstances
           from
           it
           ,
           we
           did
           (
           though
           not
           without
           trouble
           enough
           )
           bring
           it
           to
           work
           as
           well
           as
           the
           Other
           ,
           and
           ,
           as
           to
           some
           purposes
           ,
           better
           .
           And
           having
           once
           got
           This
           ,
           I
           made
           hast
           to
           try
           with
           it
           those
           Experiments
           ,
           that
           belonged
           to
           the
           design'd
           Continuation
           ,
           and
           do
           now
           make
           up
           this
           Book
           .
        
         
           I
           hope
           ,
           that
           to
           such
           Readers
           as
           the
           following
           Papers
           are
           principally
           intended
           for
           ,
           I
           shall
           not
           need
           to
           make
           an
           Apology
           either
           for
           the
           Plainenesse
           of
           my
           Style
           ,
           (
           wherein
           I
           aim'd
           at
           Perspicuity
           ,
           not
           Eloquence
           ,
           )
           or
           for
           my
           not
           having
           adorn'd
           or
           stufft
           this
           Treatise
           with
           Authorities
           or
           Sentences
           of
           Classick
           Authors
           ,
           which
           I
           had
           neither
           the
           leisure
           to
           seek
           ,
           nor
           thought
           I
           had
           any
           great
           need
           to
           imploy
           ,
           though
           it
           had
           been
           far
           more
           easie
           then
           perhaps
           it
           would
           have
           proved
           ,
           to
           borrow
           from
           them
           things
           that
           would
           have
           been
           very
           proper
           to
           a
           Treatise
           where
           my
           main
           Design
           was
           ,
           to
           make
           out
           by
           practicable
           Experiments
           divers
           things
           among
           other
           that
           have
           not
           hitherto
           been
           advantaged
           by
           that
           way
           of
           Probation
           ,
           nor
           perchance
           thought
           very
           capable
           of
           it
           ;
           so
           that
           I
           shall
           have
           obtained
           a
           great
           part
           of
           what
           I
           aim'd
           at
           ,
           if
           I
           have
           shewn
           ,
           that
           those
           very
           Phaenomena
           ,
           which
           the
           School-Philosophers
           ,
           and
           their
           party
           urge
           ,
           
           and
           sometimes
           triumph
           in
           ,
           as
           clear
           Proofs
           of
           Natures
           abhorrency
           of
           a
           Vacuum
           ,
           may
           be
           not
           onely
           explicated
           ,
           but
           actually
           exhibited
           ,
           some
           by
           the
           Gravity
           ,
           and
           some
           also
           by
           the
           bare
           Spring
           of
           the
           Air.
           Which
           Latter
           I
           now
           mention
           as
           a
           distinct
           thing
           from
           the
           other
           ,
           not
           that
           I
           think
           it
           is
           actually
           separated
           in
           these
           Tryals
           ,
           (
           since
           the
           Weight
           of
           the
           upper
           parts
           of
           the
           Air
           does
           ,
           if
           I
           may
           so
           speak
           ,
           bend
           the
           Springs
           of
           the
           lower
           ,
           )
           but
           because
           that
           having
           in
           the
           already
           published
           Experiments
           ,
           and
           even
           in
           some
           of
           These
           ,
           manifested
           the
           Efficacy
           of
           the
           Airs
           gravitation
           on
           Bodies
           ,
           I
           thought
           fit
           to
           make
           it
           my
           Task
           in
           many
           of
           These
           ,
           to
           shew
           ,
           that
           most
           of
           the
           same
           things
           that
           are
           done
           by
           the
           Pressure
           of
           all
           the
           superincumbent
           Atmosphere
           acting
           as
           a
           VVeight
           ,
           may
           be
           likewise
           performed
           by
           the
           Pressure
           of
           a
           small
           portion
           of
           Air
           ,
           included
           indeed
           (
           but
           without
           any
           new
           Compression
           )
           acting
           as
           a
           Spring
           .
        
         
           The
           present
           first
           part
           of
           our
           Continuation
           might
           I
           confesse
           have
           been
           not
           inconveniently
           divided
           into
           two
           parts
           .
           For
           first
           it
           contains
           some
           Experiments
           that
           are
           already
           related
           in
           the
           Printed
           book
           ,
           though
           they
           be
           here
           so
           repeated
           ,
           as
           to
           be
           confirmed
           ,
           illustrated
           ,
           or
           improved
           ,
           by
           being
           reiterated
           either
           with
           better
           Instruments
           ,
           or
           with
           better
           Successe
           than
           when
           they
           were
           made
           in
           my
           large
           Receiver
           ,
           which
           holding
           (
           if
           I
           misremember
           not
           )
           about
           eight
           Gallons
           ,
           could
           not
           easily
           be
           so
           well
           exhausted
           as
           those
           small
           Receivers
           I
           often
           
           since
           imployed
           .
           And
           secondly
           ,
           the
           other
           and
           far
           more
           numerous
           sort
           of
           Experiments
           ,
           related
           in
           this
           First
           part
           ,
           are
           new
           and
           superadded
           .
           And
           yet
           I
           forbear
           to
           assign
           each
           of
           these
           two
           sorts
           a
           place
           by
           it self
           ,
           because
           I
           could
           not
           conveniently
           set
           down
           my
           Tryals
           otherwise
           then
           as
           they
           came
           to
           hand
           among
           my
           Notes
           ;
           and
           I
           considered
           ,
           that
           in
           divers
           places
           the
           New
           ones
           and
           the
           Old
           ones
           being
           mentioned
           together
           ,
           might
           serve
           by
           their
           neighbourhood
           to
           illustrate
           or
           confirm
           each
           other
           .
           And
           however
           at
           another
           Edition
           of
           our
           Continuation
           it
           will
           be
           a
           very
           easie
           task
           ,
           if
           it
           appear
           to
           be
           a
           requisite
           one
           ,
           to
           give
           the
           improvements
           of
           the
           former
           Experiments
           ,
           and
           the
           superadded
           new
           ones
           ,
           distinct
           Titles
           and
           Places
           .
        
         
           As
           for
           the
           Mechanical
           contrivances
           I
           imployed
           in
           making
           the
           following
           Experiments
           ,
           though
           most
           of
           them
           have
           had
           the
           good
           fortune
           to
           meet
           with
           an
           approbation
           ,
           and
           some
           of
           them
           with
           more
           than
           that
           ,
           from
           no
           mean
           Virtuosi
           and
           Mathematicians
           ;
           yet
           as
           I
           expect
           that
           Critical
           Readers
           will
           judg
           ,
           that
           in
           some
           Experiments
           more
           artificial
           Instruments
           might
           have
           been
           made
           use
           of
           ,
           so
           I
           hope
           that
           they
           will
           not
           look
           upon
           those
           I
           was
           reduced
           to
           imploy
           ,
           as
           alwayes
           the
           best
           that
           ever
           I
           could
           have
           directed
           ,
           since
           it
           sufficiently
           appears
           by
           diverse
           passages
           of
           the
           following
           Experiments
           ,
           that
           they
           were
           not
           made
           at
           London
           ,
           but
           in
           places
           where
           the
           want
           of
           a
           Glass-house
           and
           other
           acaccommodations
           
           reduced
           me
           to
           make
           my
           Tryals
           not
           after
           the
           best
           manner
           I
           could
           devise
           ,
           but
           in
           the
           best
           way
           I
           could
           then
           and
           there
           put
           in
           practice
           .
           And
           let
           me
           add
           on
           this
           occasion
           to
           what
           I
           have
           elsewhere
           said
           to
           the
           like
           purpose
           ,
           that
           t
           is
           both
           a
           great
           discouragement
           to
           many
           ingenious
           men
           ,
           and
           no
           small
           hinderance
           to
           the
           advancement
           of
           Natural
           Philosophy
           ,
           that
           some
           nice
           Criticks
           are
           so
           censorious
           in
           exacting
           from
           Attempters
           the
           very
           best
           Contrivances
           ,
           and
           many
           that
           would
           be
           attempters
           stand
           too
           much
           in
           awe
           of
           such
           mens
           judgments
           ;
           for
           though
           in
           very
           nice
           Experiments
           the
           exactnesse
           of
           instruments
           is
           not
           onely
           desireable
           and
           useful
           ,
           but
           in
           some
           cases
           necessary
           ;
           yet
           in
           many
           others
           ,
           where
           the
           production
           of
           a
           new
           Phaenomenon
           is
           the
           thing
           aimed
           at
           ,
           they
           are
           to
           be
           looked
           upon
           as
           Benefactors
           to
           the
           History
           of
           Nature
           ,
           that
           performe
           the
           substantial
           part
           of
           a
           Discovery
           ,
           though
           they
           do
           it
           not
           by
           the
           most
           easie
           and
           compendious
           wayes
           deviseable
           ,
           or
           attain
           not
           to
           the
           utmost
           preciseness
           that
           might
           be
           wished
           ,
           and
           is
           possible
           .
           For
           such
           performances
           ,
           notwithstanding
           their
           being
           short
           of
           perfection
           ,
           make
           discoveries
           to
           the
           World
           of
           new
           and
           useful
           things
           ;
           which
           though
           others
           ,
           that
           are
           more
           lucky
           at
           Contrivances
           ,
           and
           have
           better
           accommodations
           ,
           may
           compasse
           by
           more
           compendious
           wayes
           ,
           or
           with
           greater
           precisenesse
           ;
           yet
           still
           the
           World
           is
           beholding
           to
           the
           first
           Discovery
           for
           the
           improvements
           of
           it
           ,
           as
           we
           are
           to
           Archimedes
           
           for
           the
           first
           devising
           a
           way
           ,
           to
           find
           by
           weighing
           Bodies
           in
           Water
           ,
           how
           much
           Gold
           or
           how
           much
           Silver
           a
           mixture
           of
           those
           Metals
           does
           contain
           ,
           though
           (
           if
           Historians
           have
           not
           injured
           that
           great
           man
           in
           the
           relation
           )
           he
           went
           a
           more
           laborious
           and
           lesse
           accurate
           way
           to
           work
           than
           modern
           Hydrostatians
           ,
           who
           (
           as
           I
           elsewhere
           shew
           )
           may
           perform
           the
           same
           thing
           by
           a
           far
           better
           way
           ,
           which
           yet
           probably
           we
           should
           not
           have
           thought
           of
           ,
           if
           that
           attributed
           to
           Archimedes
           had
           not
           preceded
           ,
           and
           afforded
           us
           a
           fundamental
           Notion
           .
           And
           that
           the
           not
           being
           so
           dexterous
           at
           contriving
           the
           wayes
           to
           effect
           a
           thing
           ,
           is
           no
           sure
           argument
           that
           a
           man
           has
           not
           a
           true
           and
           solid
           knowledge
           of
           it
           ,
           we
           may
           easily
           learn
           from
           Euclid
           ,
           vvhom
           our
           Geometricians
           generally
           and
           justly
           acknowledge
           to
           be
           their
           Master
           ,
           and
           to
           have
           enriched
           the
           World
           with
           many
           useful
           Truths
           ,
           and
           solidly
           demonstrated
           all
           his
           Propositions
           ,
           though
           divers
           of
           his
           modern
           Commentators
           have
           found
           out
           more
           compendious
           wayes
           for
           effecting
           several
           of
           his
           Problems
           ,
           as
           vvell
           as
           of
           demonstrating
           divers
           of
           his
           Theorems
           ,
           especially
           since
           the
           excellent
           invention
           of
           
             specious
             Algebra
          
           ,
           by
           whose
           help
           that
           accurate
           Mathematician
           Dr.
           Wallis
           has
           ,
           besides
           other
           Specimens
           upon
           intricate
           Propositions
           ,
           clearly
           demonstrated
           the
           ten
           first
           and
           for
           the
           most
           part
           perplexing
           Theorems
           of
           the
           second
           Element
           ,
           in
           litle
           more
           than
           as
           few
           lines
           .
           In
           summe
           ,
           in
           Experiments
           
           that
           are
           very
           nice
           ,
           accurate
           Contrivances
           and
           Instruments
           are
           industriously
           to
           be
           sought
           ,
           and
           highly
           to
           be
           valued
           ,
           and
           even
           in
           such
           other
           Experiments
           as
           are
           frequently
           to
           be
           reiterated
           the
           most
           commodious
           and
           easie
           ways
           of
           performing
           them
           are
           very
           desireable
           ,
           but
           those
           practical
           Compendiums
           ,
           though
           very
           welcome
           to
           them
           that
           would
           repeat
           Tryals
           ,
           are
           not
           so
           important
           to
           the
           generality
           of
           Readers
           ,
           as
           being
           but
           useful
           to
           save
           pains
           ,
           not
           necessary
           to
           discover
           Truths
           ;
           to
           vvhich
           men
           may
           oftentimes
           do
           good
           service
           ,
           without
           any
           peculiar
           gift
           at
           Mechanical
           Contrivances
           ,
           since
           in
           most
           cases
           They
           may
           be
           lookt
           upon
           as
           promoters
           of
           Natural
           Philosophy
           ,
           who
           devise
           Experiments
           fit
           to
           discover
           a
           new
           Truth
           if
           the
           attempt
           succeeds
           ,
           and
           propose
           wayes
           of
           bringing
           it
           to
           Trial
           ,
           which
           though
           perhaps
           not
           the
           most
           skilful
           or
           expeditious
           ,
           are
           yet
           sufficient
           and
           practicable
           ,
           the
           increase
           of
           Physical
           knowledg
           being
           the
           product
           of
           the
           things
           themselves
           that
           are
           discovered
           ,
           whatever
           were
           the
           Instruments
           men
           imploied
           about
           making
           the
           Discoveries
           .
        
         
           As
           for
           the
           Cuts
           ,
           I
           endeavoured
           to
           make
           their
           Relations
           ,
           and
           Descriptions
           of
           most
           of
           the
           Experiments
           ,
           so
           full
           and
           plain
           ,
           as
           to
           need
           as
           few
           Schemes
           as
           might
           be
           to
           illustrate
           them
           :
           but
           though
           I
           hope
           ,
           that
           they
           who
           either
           were
           verst
           in
           such
           kind
           of
           Studies
           ,
           or
           have
           any
           peculiar
           facility
           of
           imagining
           ,
           would
           well
           enough
           conceive
           my
           meaning
           onely
           by
           words
           ;
           yet
           lest
           my
           
           own
           accustomance
           to
           devise
           such
           Trials
           ,
           and
           to
           see
           these
           made
           ,
           should
           make
           me
           think
           them
           more
           easily
           intelligible
           than
           most
           Readers
           will
           find
           them
           ,
           I
           advised
           with
           a
           Learned
           friend
           or
           two
           ,
           fit
           to
           be
           consulted
           on
           such
           an
           occasion
           ,
           what
           Experiments
           were
           requisite
           to
           be
           illustrated
           with
           Diagrams
           ,
           and
           to
           such
           I
           took
           care
           they
           should
           be
           annexed
           .
           Onely
           I
           forbore
           to
           adde
           to
           the
           Figure
           of
           each
           Instrument
           Alphabetical
           explications
           of
           its
           parts
           ,
           as
           judging
           that
           troublesome
           work
           lesse
           easie
           for
           me
           ,
           than
           it
           would
           be
           for
           such
           Readers
           as
           this
           Tract
           is
           designed
           for
           ,
           to
           understand
           what
           is
           delivered
           by
           the
           help
           of
           a
           litle
           Attention
           in
           conferring
           the
           Schemes
           of
           the
           Instruments
           with
           the
           Verbal
           accounts
           of
           the
           Experiments
           they
           relate
           to
           .
           But
           there
           is
           one
           Particular
           about
           the
           Cuts
           may
           require
           both
           to
           be
           given
           notice
           of
           and
           excused
           :
           which
           is
           ,
           that
           having
           occasion
           to
           alter
           the
           method
           of
           my
           Experiments
           ,
           when
           I
           began
           to
           foresee
           that
           I
           should
           be
           obliged
           to
           reserve
           divers
           things
           for
           another
           opportunity
           ;
           and
           being
           my self
           absent
           from
           the
           Graver
           for
           a
           good
           part
           of
           the
           time
           he
           was
           at
           work
           ,
           some
           of
           the
           Cuts
           were
           misplaced
           ,
           and
           not
           graven
           in
           the
           Plates
           ,
           in
           which
           ,
           according
           to
           the
           present
           series
           of
           Experiments
           ,
           they
           might
           most
           properly
           have
           been
           put
           .
        
         
           But
           perhaps
           I
           may
           (
           for
           I
           am
           not
           sure
           of
           it
           )
           more
           need
           the
           Readers
           pardon
           for
           (
           unknowingly
           )
           troubling
           him
           in
           this
           Continuation
           with
           some
           passages
           ,
           
           that
           he
           may
           have
           already
           met
           with
           in
           the
           Book
           it
           refers
           to
           :
           which
           though
           I
           had
           not
           read
           over
           for
           some
           years
           before
           ,
           I
           chanced
           not
           to
           have
           at
           hand
           ,
           when
           divers
           of
           the
           following
           Papers
           were
           written
           ;
           and
           though
           afterwards
           I
           recovered
           it
           ,
           yet
           the
           indisposition
           of
           my
           Eyes
           made
           me
           think
           it
           unfit
           rather
           to
           tire
           them
           by
           reading
           over
           the
           whole
           Book
           ,
           than
           to
           trust
           to
           the
           Readers
           good
           Nature
           (
           in
           case
           I
           should
           need
           it
           )
           for
           the
           pardon
           of
           a
           few
           unintended
           Repetitions
           .
        
         
           I
           doubt
           not
           ,
           many
           Readers
           will
           be
           inquisitive
           to
           know
           ,
           why
           this
           Treatise
           is
           stiled
           the
           First
           part
           of
           a
           Continuation
           :
           To
           give
           these
           some
           account
           of
           the
           Title
           ,
           I
           must
           put
           them
           in
           mind
           ,
           that
           in
           the
           already
           published
           Experiments
           I
           intimated
           ,
           that
           two
           sorts
           of
           Tryals
           might
           be
           made
           by
           the
           help
           of
           our
           Engine
           :
           the
           one
           ,
           such
           as
           needed
           but
           a
           short
           absence
           of
           the
           Air
           ,
           and
           the
           other
           such
           as
           required
           that
           the
           Air
           should
           not
           onely
           be
           withdrawn
           for
           a
           vvhile
           ,
           but
           kept
           out
           for
           a
           considerable
           time
           ,
           from
           the
           Bodies
           vvhereupon
           the
           trial
           is
           made
           .
           Of
           the
           former
           sort
           of
           Experiments
           are
           these
           this
           present
           Book
           does
           (
           as
           vvell
           as
           that
           heretofore
           published
           did
           )
           consist
           of
           .
           And
           though
           I
           have
           been
           so
           much
           called
           upon
           ,
           and
           troubled
           for
           certain
           Writings
           ,
           whereof
           I
           had
           made
           such
           mention
           in
           those
           that
           past
           the
           Presse
           ,
           as
           some
           Readers
           interpreted
           to
           be
           an
           engagement
           ,
           that
           it
           made
           me
           think
           fit
           ,
           when
           I
           satisfied
           their
           demands
           ,
           to
           be
           thence
           forward
           very
           shy
           
           of
           making
           the
           Publick
           any
           promise
           ;
           yet
           I
           was
           induced
           not
           to
           alter
           the
           Title
           of
           this
           Treatise
           ,
           partly
           because
           it
           may
           intimate
           to
           the
           Curious
           ,
           that
           there
           are
           yet
           a
           great
           many
           things
           to
           be
           performed
           by
           our
           Engine
           ,
           besides
           the
           productions
           of
           it
           I
           have
           hitherto
           presented
           them
           ,
           and
           partly
           because
           ,
           though
           I
           still
           persist
           in
           my
           former
           aversnesse
           to
           make
           promises
           to
           the
           World
           ;
           yet
           t
           is
           very
           possible
           ,
           that
           if
           God
           grant
           me
           life
           and
           health
           ,
           I
           may
           in
           due
           time
           present
           my
           Friends
           with
           what
           may
           serve
           for
           a
           Second
           part
           of
           our
           Continuation
           ,
           consisting
           of
           Experiments
           that
           require
           a
           longer
           absence
           of
           the
           Air
           from
           the
           bodies
           to
           be
           wrought
           upon
           ;
           and
           I
           shall
           think
           ,
           if
           this
           First
           part
           prove
           not
           unacceptable
           to
           the
           Curious
           ,
           that
           the
           Latter
           will
           be
           not
           unwelcome
           to
           them
           ,
           as
           being
           designed
           to
           consist
           of
           Sets
           of
           Experiments
           ,
           which
           by
           their
           being
           most
           of
           them
           New
           ,
           and
           some
           of
           them
           odd
           enough
           ,
           may
           perchance
           afford
           some
           not
           despicable
           hints
           to
           the
           Speculative
           .
           But
           the
           very
           nature
           of
           these
           Experiments
           ,
           requiring
           that
           some
           of
           them
           should
           be
           long
           in
           making
           ,
           my
           Friends
           could
           not
           reasonably
           expect
           a
           quick
           dispatch
           of
           a
           work
           of
           this
           kind
           ,
           though
           I
           should
           not
           meet
           for
           the
           future
           with
           such
           intervening
           impediments
           ,
           as
           have
           hitherto
           disturbed
           it
           ,
           (
           as
           want
           of
           instruments
           ,
           of
           health
           ,
           of
           leisure
           ,
           and
           of
           the
           liberty
           ,
           which
           is
           so
           requisite
           in
           this
           case
           ,
           of
           staying
           long
           enough
           in
           one
           place
           :
           )
           notwithstanding
           all
           which
           difficulties
           I
           have
           by
           
           snatches
           been
           able
           through
           God's
           blessing
           to
           make
           forty
           or
           fifty
           of
           designed
           Tryals
           ,
           being
           such
           as
           require
           the
           least
           of
           time
           to
           be
           performed
           in
           ,
           though
           I
           now
           think
           not
           fit
           to
           mention
           any
           of
           them
           ,
           as
           well
           for
           other
           reasons
           ,
           as
           because
           though
           they
           be
           made
           by
           the
           help
           of
           our
           Engine
           ,
           yet
           they
           require
           a
           peculiar
           apparatus
           of
           Instruments
           ,
           very
           differing
           from
           those
           we
           have
           hitherto
           mentioned
           ,
           and
           not
           to
           be
           intelligibly
           described
           without
           many
           words
           and
           divers
           figures
           .
           In
           the
           mean
           time
           ,
           lest
           the
           industrious
           should
           be
           discouraged
           by
           a
           surmise
           ,
           that
           there
           is
           nothing
           left
           for
           them
           to
           do
           by
           the
           help
           of
           our
           Engine
           ,
           at
           least
           as
           to
           the
           first
           sort
           of
           Experiments
           ,
           I
           shall
           inform
           them
           ,
           that
           I
           had
           thoughts
           to
           have
           added
           divers
           others
           of
           that
           kind
           to
           these
           that
           now
           come
           forth
           ,
           and
           particularly
           two
           Clusters
           of
           Pneumatical
           trials
           ,
           the
           one
           about
           Respiration
           ,
           and
           the
           other
           about
           Fire
           and
           Flame
           ;
           but
           several
           of
           my
           Notes
           and
           Observations
           being
           at
           present
           out
           of
           the
           way
           ,
           my
           having
           neither
           health
           nor
           leisure
           to
           repair
           these
           inconveniences
           ,
           and
           prosecute
           Tryals
           of
           that
           sort
           with
           any
           assiduity
           ,
           makes
           me
           chuse
           rather
           to
           reserve
           them
           for
           an
           Appendix
           ,
           than
           to
           make
           those
           that
           now
           come
           abroad
           stay
           for
           them
           .
           Which
           will
           not
           (
           I
           presume
           )
           be
           the
           more
           disliked
           ,
           because
           by
           taking
           this
           course
           I
           may
           ,
           in
           delivering
           of
           the
           phaenomena
           of
           Nature
           ,
           imitate
           Nature
           her self
           ,
           
           of
           whom
           t
           is
           the
           Roman
           Philosophers
           saying
           ,
           
             Rerum
             Natura
             sacra
             sua
             non
             simul
             tradit
             .
          
        
         
           
           
             Some
             Advertisements
             touching
             the
             Engine
             it self
             .
          
           
             THough
             the
             Engine
             already
             published
             ,
             and
             that
             which
             I
             imployed
             in
             the
             following
             Tryals
             ,
             have
             the
             same
             Uses
             ,
             &
             agree
             both
             in
             the
             ground
             and
             the
             main
             part
             of
             their
             Construction
             ,
             yet
             they
             differ
             in
             some
             particulars
             fit
             to
             be
             taken
             notice
             of
             :
             for
             after
             I
             had
             presented
             the
             great
             Engine
             I
             formerly
             made
             use
             of
             to
             the
             Royal
             Society
             ,
             partly
             the
             difficulty
             of
             procuring
             such
             another
             of
             that
             Size
             and
             Make
             ,
             and
             partly
             the
             desire
             of
             making
             some
             improvements
             invited
             me
             to
             make
             some
             alterations
             in
             the
             Structure
             ;
             some
             of
             them
             suggested
             by
             others
             ,
             (
             especially
             by
             the
             Ingenious
             M
             r
             Hook
             ,
             )
             and
             some
             of
             them
             that
             I
             added
             my self
             ,
             as
             finding
             that
             without
             them
             I
             could
             not
             do
             my
             work
             .
             Wherefore
             it
             will
             not
             be
             amiss
             to
             point
             at
             the
             chief
             differences
             between
             the
             former
             and
             the
             latter
             Engine
             ,
             and
             to
             intimate
             some
             of
             the
             conveniences
             and
             inconveniences
             that
             attend
             them
             .
          
           
             As
             for
             the
             Construction
             of
             the
             second
             Engine
             it self
             ,
             since
             t
             is
             presumed
             ,
             that
             the
             Readers
             of
             this
             Book
             have
             already
             perused
             That
             of
             which
             this
             is
             a
             Continuation
             ,
             and
             understood
             the
             contrivance
             of
             the
             Instrument
             that
             belongs
             to
             it
             ,
             it
             was
             presumed
             sufficient
             to
             exhibit
             in
             the
             first
             Plate
             the
             delineation
             of
             the
             entire
             Engine
             ready
             to
             be
             set
             at
             work
             ;
             and
             in
             the
             second
             ,
             the
             figures
             of
             the
             several
             Metalline
             parts
             that
             compose
             it
             ,
             before
             they
             are
             set
             together
             .
             For
             though
             these
             have
             not
             verbal
             and
             Alphabetical
             explications
             annexed
             to
             them
             ,
             yet
             the
             sight
             of
             them
             may
             suffice
             to
             make
             those
             that
             have
             an
             imagination
             fitted
             to
             conceive
             Mechanical
             contrivances
             ,
             and
             are
             acquainted
             with
             the
             former
             Engine
             ,
             comprehend
             the
             structure
             of
             this
             ;
             which
             ,
             Alphabetical
             explications
             would
             scarce
             make
             such
             Readers
             do
             ,
             as
             are
             not
             so
             qualified
             :
             onely
             two
             things
             there
             are
             ,
             which
             being
             of
             some
             difficulty
             ,
             as
             well
             as
             of
             importance
             to
             be
             conceived
             ,
             I
             shall
             here
             particularly
             
             tak
             notice
             of
             .
             The
             first
             of
             which
             is
             ,
             that
             in
             regard
             the
             Sucker
             is
             to
             be
             alwayes
             under
             water
             ,
             and
             the
             perforation
             
               p
               q
            
             ,
             that
             passes
             perpendicularly
             quite
             through
             it
             ,
             and
             serves
             together
             with
             the
             stick
             
               r
               s
            
             for
             a
             Valve
             ,
             is
             to
             be
             stopt
             at
             the
             bottom
             of
             the
             Cylinder
             ,
             as
             at
             
               n
               o
            
             ,
             when
             t
             is
             full
             of
             water
             ,
             t
             was
             requisite
             to
             make
             the
             stick
             
               r
               p
            
             of
             a
             considerable
             length
             ,
             as
             two
             or
             three
             foot
             :
             The
             other
             and
             chief
             thing
             is
             that
             in
             the
             second
             Plate
             ,
             the
             Pipe
             AB
             ,
             whose
             end
             B
             bends
             upward
             ,
             is
             made
             to
             lie
             in
             a
             gruve
             or
             gutter
             purposely
             made
             in
             the
             flat
             wooden
             Board
             
               c
               d
               e
               f
            
             ,
             on
             which
             the
             Receivers
             are
             to
             rest
             ;
             which
             square
             board
             I
             caused
             to
             be
             overlaid
             with
             very
             good
             Cement
             ,
             on
             which
             I
             took
             care
             to
             apply
             a
             strong
             plate
             of
             iron
             ,
             of
             the
             bigness
             and
             shape
             of
             the
             Board
             ,
             leaving
             onely
             a
             small
             hole
             for
             the
             erected
             part
             of
             the
             Pipe
             to
             come
             out
             at
             ,
             which
             I
             added
             ,
             not
             onely
             to
             keep
             the
             wooden
             Board
             the
             better
             from
             warping
             ,
             but
             because
             I
             knew
             (
             what
             will
             perhaps
             be
             thought
             strange
             )
             that
             the
             pressure
             of
             the
             Atmosphere
             on
             one
             side
             of
             the
             Board
             ,
             when
             there
             is
             no
             pressure
             or
             but
             very
             litle
             on
             the
             other
             side
             ,
             will
             enable
             many
             Aerial
             particles
             to
             strain
             through
             the
             very
             wood
             ,
             though
             of
             a
             good
             thickness
             ,
             and
             imbued
             with
             oyl
             to
             choak
             the
             Pores
             ;
             to
             this
             iron-plate
             we
             sometimes
             fit
             a
             Lip
             turning
             up
             about
             it
             ,
             to
             hinder
             the
             Water
             that
             on
             some
             occasions
             will
             come
             from
             the
             Receiver
             from
             falling
             on
             the
             Room
             ;
             (
             and
             to
             add
             that
             upon
             the
             by
             )
             though
             the
             Stop-cock
             
               g
               h
               i
               k
            
             ,
             that
             belongs
             to
             the
             hitherto
             mentioned
             Pipe
             ,
             may
             be
             inserted
             at
             I.
             into
             the
             Barrel
             or
             Cylinder
             
               l
               m
               n
               o
            
             by
             the
             help
             of
             Soder
             ,
             yet
             we
             chose
             as
             a
             much
             better
             way
             to
             have
             the
             Branch
             I.
             of
             the
             Stop-cock
             made
             like
             a
             Screw
             ,
             which
             being
             once
             firmly
             screwed
             in
             to
             the
             Barrel
             ,
             is
             not
             apt
             to
             be
             broken
             off
             ,
             and
             may
             be
             more
             easily
             mended
             if
             any
             thing
             happen
             to
             be
             out
             of
             order
             ,
             which
             the
             Engine
             is
             the
             most
             liable
             to
             be
             in
             or
             about
             the
             Pipe
             ,
             partly
             because
             it
             may
             fall
             out
             ,
             (
             though
             but
             very
             rarely
             if
             due
             care
             be
             but
             taken
             ,
             )
             that
             the
             Air
             will
             insinuate
             it self
             between
             the
             wooden
             Board
             and
             the
             iron-plate
             ,
             and
             so
             get
             up
             (
             where
             the
             Pipe
             bends
             upwards
             )
             into
             the
             cavity
             of
             the
             Receiver
             ,
             and
             partly
             because
             the
             Pipe
             being
             for
             a
             just
             reason
             
             made
             but
             slender
             ,
             and
             the
             part
             of
             it
             that
             looks
             upwards
             very
             short
             ,
             it
             happens
             not
             very
             unfrequently
             ,
             that
             when
             we
             imploy
             Receivers
             with
             narrow
             Orifices
             ,
             where
             the
             Cement
             must
             lie
             close
             to
             the
             opening
             of
             the
             Pipe
             ,
             it
             happens
             ,
             I
             say
             ,
             that
             the
             Cement
             ,
             especially
             if
             it
             be
             much
             softned
             by
             heat
             ,
             is
             suckt
             (
             as
             they
             speak
             )
             into
             the
             Pipe
             ,
             and
             so
             choaks
             it
             up
             ;
             or
             else
             that
             some
             part
             of
             the
             body
             included
             in
             the
             Receiver
             is
             drawn
             to
             the
             orifice
             of
             the
             Pipe
             ,
             and
             lying
             upon
             it
             as
             a
             Cover
             hinders
             the
             free
             passage
             of
             the
             Air
             into
             the
             Barrel
             ,
             against
             which
             inconvenience
             ,
             to
             add
             that
             upon
             the
             by
             ,
             we
             use
             amongst
             other
             Expedients
             to
             place
             just
             about
             the
             Orifice
             of
             the
             Pipe
             a
             small
             cover
             of
             Tin
             ,
             like
             that
             of
             a
             litle
             Box
             ,
             which
             covers
             it
             at
             the
             top
             to
             hinder
             any
             thing
             from
             lying
             immediately
             upon
             the
             Pipe
             ,
             and
             has
             a
             small
             opening
             or
             two
             in
             the
             side
             ,
             to
             give
             the
             Air
             of
             the
             Receiver
             free
             access
             to
             the
             Pipe.
             
          
           
             The
             square
             and
             hollow
             wooden
             part
             of
             this
             Engine
             ,
             discernable
             in
             the
             first
             plate
             ,
             is
             so
             made
             ,
             that
             it
             may
             contain
             not
             onely
             the
             Cylinder
             ,
             but
             so
             much
             water
             ,
             as
             will
             alwaies
             keep
             the
             Cylinder
             quite
             cover'd
             with
             that
             liquor
             ;
             by
             which
             means
             the
             Sucker
             ,
             lying
             &
             playing
             alwaies
             under
             water
             ,
             is
             kept
             still
             turgid
             and
             plump
             ,
             and
             the
             water
             being
             ready
             at
             hand
             to
             fill
             up
             any
             litle
             interval
             or
             chink
             ,
             that
             may
             happen
             to
             be
             between
             the
             Sucker
             and
             the
             inside
             of
             the
             Barrel
             ,
             does
             together
             with
             the
             newly
             mentioned
             plumpness
             of
             the
             Sucker
             very
             much
             conduce
             to
             the
             exact
             keeping
             out
             of
             the
             Air.
             But
             this
             advantage
             is
             not
             without
             some
             inconvenience
             ,
             for
             divers
             times
             ,
             if
             great
             care
             be
             not
             taken
             in
             turning
             the
             Stop-cock
             ,
             the
             water
             will
             be
             impell'd
             into
             the
             Receiver
             ,
             and
             much
             prejudice
             sundry
             Experiments
             ,
             when
             the
             included
             bodies
             are
             such
             that
             may
             be
             spoiled
             or
             impaired
             (
             at
             least
             for
             the
             present
             )
             by
             that
             liquor
             .
             The
             smalness
             of
             our
             Cylinder
             is
             a
             convenience
             in
             regard
             of
             the
             facility
             it
             affords
             to
             make
             and
             dispatch
             those
             many
             Experiments
             that
             may
             be
             performed
             in
             small
             Receivers
             ,
             though
             it
             make
             those
             more
             troublesome
             and
             tedious
             ,
             that
             require
             the
             Exhaustion
             of
             large
             and
             capacious
             ones
             .
          
           
             The
             flat
             Plate
             (
             mentioned
             a
             litle
             above
             )
             has
             this
             great
             conveniency
             
             in
             many
             Experiments
             ,
             that
             the
             Receiver
             needs
             no
             Stop-cock
             of
             its
             own
             ;
             for
             such
             a
             vessel
             being
             made
             all
             of
             an
             entire
             piece
             of
             Glass
             ,
             and
             whelmed
             on
             upon
             the
             Plate
             well
             covered
             with
             Cement
             ,
             can
             better
             keep
             out
             the
             Air
             ,
             than
             if
             there
             were
             a
             stop-cock
             ,
             at
             which
             the
             Air
             does
             but
             too
             frequently
             get
             in
             ;
             but
             besides
             that
             in
             divers
             Experiments
             such
             Receivers
             do
             usually
             require
             to
             be
             wide
             mouthed
             ,
             whereby
             a
             greater
             compass
             is
             to
             be
             fenced
             against
             the
             ingress
             of
             the
             Air
             ,
             several
             Experiments
             cannot
             so
             conveniently
             be
             tryed
             in
             this
             sort
             of
             Receivers
             .
          
           
             But
             because
             ,
             that
             though
             this
             second
             form
             of
             our
             Engine
             hath
             as
             to
             several
             purposes
             its
             peculiar
             conveniences
             and
             advantages
             ,
             yet
             some
             Virtuosi
             may
             be
             furnished
             with
             the
             other
             already
             ,
             and
             some
             may
             conceive
             it
             the
             more
             clearly
             of
             the
             two
             ,
             or
             may
             judg
             it
             preferable
             for
             their
             particular
             designs
             ;
             I
             shall
             here
             intimate
             ,
             that
             for
             most
             of
             the
             Experiments
             ,
             if
             not
             all
             ,
             that
             follow
             in
             this
             Treatise
             ,
             they
             may
             make
             use
             of
             ,
             or
             at
             least
             make
             a
             shift
             with
             the
             first
             Engine
             ,
             with
             a
             very
             few
             alterations
             ;
             whereof
             the
             chief
             is
             to
             be
             this
             ,
             That
             to
             the
             upper
             part
             of
             the
             great
             Cylinder
             ,
             on
             the
             side
             opposite
             to
             the
             iron-rack
             ,
             there
             is
             to
             be
             fastned
             such
             a
             square
             Board
             ,
             and
             suitable
             iron-plate
             ,
             as
             is
             used
             in
             the
             second
             Engine
             ,
             betwixt
             which
             Board
             and
             Plate
             is
             to
             be
             lodged
             such
             a
             Pipe
             as
             was
             lately
             described
             ,
             being
             either
             a
             continuation
             of
             the
             outward
             branch
             of
             the
             Stop-cock
             ,
             or
             else
             firmly
             fastned
             to
             it
             by
             sodering
             or
             screwing
             :
             for
             by
             this
             means
             ,
             when
             the
             Sucker
             is
             deprest
             ,
             the
             Air
             will
             through
             the
             Cavity
             of
             this
             Pipe
             ,
             and
             the
             Stop-cock
             whereto
             it
             is
             annexed
             ,
             pass
             freely
             by
             virtue
             of
             its
             own
             Spring
             out
             of
             the
             Receiver
             into
             the
             exhausted
             Cylinder
             ;
             though
             this
             ,
             and
             the
             Sucker
             that
             moves
             in
             it
             ,
             being
             not
             kept
             as
             in
             the
             second
             form
             of
             the
             Engine
             under
             water
             ,
             the
             greater
             care
             will
             be
             needed
             to
             keep
             the
             Air
             from
             insinuating
             it self
             between
             them
             .
             A
             good
             Cement
             ,
             to
             fasten
             the
             Receivers
             to
             the
             often
             mentioned
             Plate
             of
             Iron
             ,
             is
             a
             thing
             of
             no
             small
             moment
             in
             making
             the
             following
             Experiments
             ,
             of
             which
             we
             imploy
             differing
             Compositions
             for
             differing
             purposes
             ,
             some
             of
             which
             are
             not
             necessary
             to
             be
             mentioned
             
             in
             that
             part
             of
             this
             work
             that
             now
             comes
             forth
             ;
             but
             that
             which
             in
             almost
             all
             the
             following
             Tryals
             we
             chiefly
             make
             use
             of
             ,
             is
             a
             well
             wrought
             mixture
             of
             (
             yellow
             )
             Bees
             wax
             and
             Turpentine
             ,
             which
             composition
             as
             it
             serves
             better
             than
             most
             others
             to
             keep
             out
             the
             Air
             ,
             so
             it
             has
             the
             conveniency
             ,
             which
             is
             no
             small
             one
             ,
             of
             seldome
             needing
             to
             be
             heated
             ,
             and
             seldomer
             to
             be
             much
             so
             ;
             especially
             if
             we
             imploy
             a
             litle
             more
             Turpentine
             in
             Winter
             than
             in
             Summer
             ,
             in
             the
             former
             of
             which
             seasons
             ,
             as
             much
             ,
             or
             very
             near
             as
             much
             of
             that
             ingredient
             as
             of
             the
             Wax
             does
             well
             ,
             for
             as
             in
             Summer
             a
             mixture
             of
             three
             parts
             of
             Wax
             to
             about
             two
             of
             Turpentine
             is
             more
             proper
             .
          
        
      
       
         
           ERRATA
           .
        
         
           
             By
             an
             oversight
             a
             short
             Paragraph
             was
             omitted
             in
             the
             14.
             page
             ,
             importing
             ,
             that
          
           the
           second
           figure
           of
           the
           4th
           .
           Plate
           was
           designed
           onely
           to
           make
           some
           representation
           of
           the
           difference
           that
           would
           appear
           ,
           if
           instead
           of
           making
           the
           4.
           
           Experiment
           with
           Water
           ,
           as
           in
           the
           foregoing
           figure
           ,
           the
           Tryal
           was
           made
           with
           Quick-silver
           .
        
         
           
             So
             lik
             wise
             in
          
           pag.
           104.
           lin
           .
           4.
           
             and
             8.
             for
          
           14
           of
           the
           12
           Book
           read
           14
           of
           the
           11.
           pag.
           ib.
           l.
           9.
           read
           Cylinders
           of
           equal
           heights
           are
           to
           one
           another
           as
           their
           Bases
           .
        
      
       
         
         
           The
           Reader
           is
           desired
           to
           perfect
           with
           his
           Pen
           the
           marginal
           Notes
           referring
           to
           the
           Plates
           as
           being
           defective
           ,
           and
           also
           to
           insert
           such
           others
           as
           were
           wholly
           omitted
           ,
           according
           to
           the
           following
           Directions
           ;
           which
           could
           not
           otherwise
           be
           conveniently
           supplied
           ,
           without
           putting
           a
           stop
           to
           the
           Press
           .
        
         
           
             In
             the
             Margent
             of
             Page
             the
             —
          
           
             
               3
               
               d.
               read
            
             See
             Plate
             the
             III.
             Figure
             the
             1.
             
          
           
             14.
             r.
             See
             plate
             the
             IV.
             figure
             the
             2.
             
          
           
             30.
             r.
             See
             plate
             the
             III.
             figure
             the
             2.
             
          
           
             33.
             r.
             plate
             the
             III.
             fig.
             the
             2.
             
          
           
             34.
             
             See
             plate
             the
             III.
             figure
             the
             3.
             
          
           
             43.
             r.
             See
             plate
             the
             V.
             figure
             the
             1.
             
          
           
             54.
             r.
             See
             plate
             the
             III.
             figure
             the
             4.
             
          
           
             73.
             
               against
               the
               16.
               line
               ,
               insert
            
             —
             See
             the
             whole
             Baroscope
             delineated
             Plate
             the
             V.
             fig.
             the
             2.
             
          
           
             87.
             against
             the
             last
             line
             but
             two
             ,
             insert
             —
             
               See
               plate
               the
               V.
               figure
               the
            
             3.
             
          
           
             88.
             
               against
               the
               6.
               line
               insert
            
             —
             See
             plate
             the
             V.
             figure
             the
             4.
             
          
           
             107.
             
               against
               the
               28.
               line
               ,
               insert
            
             See
             plate
             the
             VI.
             figure
             the
             1.
             
          
           
             111.
             
               against
               the
               20.
               line
               ,
               insert
            
             See
             plate
             the
             VI.
             fig.
             the
             2.
             
          
           
             
               113.
               r.
            
             See
             the
             2.
             figure
             of
             the
             7.
             plate
             :
             (
             
               adding
               thereto
            
             )
             which
             though
             made
             primarily
             for
             the
             39.
             
             Experiment
             ,
             may
             facilitate
             the
             conceiving
             of
             This.
             
          
           
             120.
             
               against
               the
               17.
               line
               ,
               insert
            
             See
             plate
             the
             VI.
             figure
             the
             3.
             
          
           
             122.
             
               against
               the
               9.
               line
               ,
               insert
            
             See
             plate
             the
             VI.
             figure
             the
             4.
             
          
           
             123.
             
               against
               the
               19.
               line
               ,
               insert
            
             See
             plate
             the
             VI.
             figure
             the
             5.
             
          
           
             125.
             
               against
               the
               14.
               line
               ,
               insert
            
             See
             plate
             the
             VI.
             figure
             the
             6.
             
          
           
             130.
             read
             See
             plate
             the
             VI.
             fig.
             the
             7.
             
          
           
             132.
             r.
             See
             plate
             the
             VII
             .
             fig.
             the
             1.
             
          
           
             136.
             
               against
               the
               8.
               line
               ,
               insert
            
             See
             plate
             the
             VII
             .
             figure
             the
             3.
             
          
           
             139.
             read
             See
             plate
             the
             VII
             .
             figure
             the
             4.
             
          
           
             144.
             r.
             See
             plate
             the
             VIII
             .
             fig.
             the
             1.
             
          
           
             155.
             r.
             See
             plate
             the
             IV.
             fig.
             the
             3.
             
          
           
             161.
             r.
             See
             plate
             the
             VIII
             .
             Fig.
             the
             2.
             and
             4.
             
          
           
             165.
             against
             the
             21.
             line
             ,
             insert
             
               See
               plate
               the
               VIII
               .
               fig.
               the
            
             4.
             and
             against
             the
             last
             line
             save
             one
             ,
             insert
             
               See
               plate
               the
               VIII
               .
               fig.
               the
            
             3.
             
          
           
             166.
             r.
             See
             plate
             the
             VIII
             .
             fig.
             the
             5.
             
          
           
             174.
             
             Within
             3
             lines
             of
             the
             bottom
             ,
             insert
             
               See
               plate
               the
               IV.
               figure
               the
            
             4.
             
          
        
      
       
         
         
           
             
               The
               I.
               Plate
               .
            
          
        
         
         
           
             
               The
               II
               Plate
               .
            
          
        
      
       
         
         
           A
           CONTINVATION
           OF
           Nevv
           Experiments
           Physico-Mechanical
           ,
           Touching
           the
           SPRING
           and
           VVEIGHT
           of
           the
           AIR
           ,
           and
           their
           Effects
           .
        
         
           THE
           I.
           PART
           .
        
         
           Written
           by
           way
           of
           Letter
           ,
           to
           the
           Right
           Honourable
           the
           Lord
           Clifford
           and
           Dungarvan
           .
        
      
    
     
       
         
         
         
           
             My
             Dear
             Lord
             ,
          
        
         
           SInce
           I
           have
           already
           in
           proper
           places
           of
           the
           
             Physico-Mechanical
             Experiments
             about
             the
             Air
          
           ,
           which
           I
           formerly
           presented
           your
           Lordship
           ,
           giv'n
           you
           a
           sufficient
           account
           of
           several
           things
           touching
           the
           Scope
           ,
           Occasion
           ,
           &c.
           of
           my
           Attempt
           ;
           it
           will
           not
           be
           necessary
           to
           make
           a
           solemn
           Preface
           to
           the
           ensuing
           Experiments
           .
           And
           therefore
           presuming
           upon
           an
           acceptance
           ,
           which
           the
           favourable
           Entertainment
           ,
           which
           your
           Lordship
           ,
           as
           well
           as
           the
           Publick
           ,
           was
           pleas'd
           to
           give
           my
           first
           Tryals
           of
           this
           kind
           ,
           encourages
           me
           to
           expect
           ,
           I
           shall
           ,
           without
           troubling
           you
           with
           any
           further
           Preface
           ,
           immediately
           fall
           upon
           a
           Continuation
           ;
           especially
           since
           Your
           Lordship
           will
           perhaps
           wonder
           ,
           that
           you
           have
           not
           receiv'd
           it
           much
           sooner
           ,
           as
           ,
           indeed
           ,
           you
           should
           have
           done
           ,
           if
           I
           had
           been
           befriended
           with
           Accommodations
           and
           Leisure
           .
        
         
           
           
             EXPERIMENT
             I.
             
          
           
             About
             the
             raising
             of
             Mercury
             to
             a
             great
             height
             in
             an
             open
             Tube
             ,
             by
             the
             spring
             of
             a
             little
             included
             Air.
             
          
           
             DIvers
             ways
             have
             been
             proposed
             to
             shew
             both
             the
             Pressure
             of
             the
             Air
             ,
             as
             the
             Atmosphere
             is
             a
             heavy
             Body
             ,
             and
             that
             the
             Air
             ,
             especially
             when
             compress'd
             by
             outward
             force
             ,
             has
             a
             Spring
             that
             enables
             it
             to
             sustain
             or
             resist
             a
             pressure
             equal
             to
             that
             of
             as
             much
             of
             the
             Atmosphere
             ,
             as
             can
             come
             to
             bear
             against
             it
             ,
             and
             also
             to
             shew
             ,
             that
             such
             Air
             as
             we
             live
             in
             ,
             and
             is
             not
             condens'd
             by
             any
             humane
             or
             adventitious
             force
             ,
             has
             not
             onely
             a
             resisting
             Spring
             ,
             but
             an
             active
             Spring
             (
             if
             I
             may
             so
             speak
             )
             in
             some
             measure
             ,
             as
             when
             it
             distends
             a
             flaccid
             or
             breaks
             a
             full-blown
             Bladder
             in
             our
             exhausted
             Receiver
             .
          
           
             But
             observing
             that
             there
             seems
             to
             want
             a
             visible
             Experiment
             to
             convince
             those
             that
             are
             not
             so
             easily
             satisfy'd
             with
             Reasons
             ,
             though
             drawn
             by
             just
             consequence
             from
             Physical
             or
             Mechanical
             Truths
             ,
             or
             even
             from
             other
             Experiments
             ,
             taking
             notice
             ,
             I
             say
             ,
             hereof
             ,
             I
             made
             the
             following
             Experiments
             ;
             not
             so
             much
             to
             prevent
             or
             removed
             a
             scruple
             no
             better
             grounded
             ,
             as
             to
             have
             a
             new
             way
             of
             making
             an
             Estimate
             by
             some
             known
             and
             determinate
             measure
             of
             the
             force
             of
             the
             bare
             Spring
             of
             the
             Air
             ,
             both
             in
             its
             natural
             state
             ,
             (
             as
             t
             is
             said
             to
             be
             when
             not
             compress'd
             nor
             ratify'd
             ,
             more
             then
             the
             free
             Air
             we
             breath
             ,
             )
             and
             according
             to
             its
             several
             degrees
             of
             Expansion
             .
          
           
             We
             took
             then
             a
             Viol
             ,
             with
             a
             neck
             not
             very
             large
             ,
             and
             having
             fill'd
             about
             a
             fourth
             part
             of
             it
             with
             Quick-silver
             ,
             we
             so
             erected
             and
             fastned
             a
             long
             and
             slender
             Pipe
             of
             Glass
             ,
             open
             at
             both
             ends
             in
             the
             neck
             of
             the
             Viol
             ,
             with
             hard
             sealing
             wax
             ,
             that
             the
             lower
             end
             reach'd
             almost
             to
             the
             bottom
             of
             the
             Quick-silver
             ,
             and
             the
             upper
             
             more
             then
             a
             yard
             above
             the
             viol
             .
             Then
             having
             blown
             in
             a
             little
             air
             ,
             to
             try
             whether
             the
             Instrument
             did
             not
             leak
             ,
             (
             which
             t
             is
             very
             difficult
             to
             keep
             such
             instruments
             from
             doing
             ,
             )
             we
             conveigh'd
             it
             into
             a
             long
             and
             slender
             Receiver
             ,
             
             fit
             for
             such
             an
             use
             ,
             and
             having
             withdrawn
             the
             Air
             as
             well
             as
             we
             could
             ,
             we
             found
             according
             to
             our
             expectation
             ,
             that
             the
             Spring
             of
             the
             Air
             ,
             included
             in
             the
             viol
             ,
             impell'd
             up
             the
             Quick-silver
             into
             the
             erected
             Pipe
             ,
             to
             the
             height
             of
             27.
             inches
             ,
             and
             having
             suffer'd
             the
             External
             air
             to
             return
             into
             the
             Receiver
             ,
             the
             Quick-silver
             subsided
             in
             the
             Tube
             ,
             sometimes
             almost
             ,
             and
             sometimes
             quite
             as
             low
             as
             the
             stagnant
             Quick-silver
             in
             the
             viol
             .
          
           
             For
             the
             better
             illustration
             of
             this
             Experiment
             ,
             thus
             summarily
             related
             ,
             but
             with
             the
             like
             success
             ,
             as
             to
             the
             main
             ,
             several
             times
             repeated
             ,
             we
             will
             subjoyn
             the
             following
             Observations
             and
             Notes
             .
          
           
             I.
             That
             we
             try'd
             this
             Experiment
             several
             times
             ,
             and
             the
             last
             time
             in
             the
             presence
             of
             the
             famous
             Savilian
             Geometer
             ,
             D
             r
             Wallis
             ,
             who
             saw
             the
             Quick-silver
             in
             the
             Pipe
             impell'd
             up
             to
             27.
             inches
             ,
             being
             one
             himself
             of
             the
             measurers
             ;
             and
             though
             at
             other
             times
             we
             found
             it
             to
             be
             much
             about
             the
             same
             height
             with
             the
             last
             ,
             yet
             once
             it
             seem'd
             plainly
             to
             be
             a
             pretty
             deal
             higher
             ;
             which
             yet
             we
             specifi'd
             not
             ,
             because
             a
             mischance
             took
             off
             the
             mark
             ,
             which
             we
             had
             made
             to
             measure
             the
             height
             by
             .
          
           
             II.
             Having
             once
             ,
             to
             try
             the
             stanchnesse
             of
             the
             viol
             ,
             blown
             in
             so
             much
             Air
             ,
             (
             without
             taking
             out
             any
             thing
             as
             we
             use
             to
             do
             in
             the
             like
             case
             )
             that
             the
             Air
             in
             the
             cavity
             of
             the
             viol
             rais'd
             and
             kept
             the
             Quicksilver
             3.
             inches
             high
             in
             the
             Pipe
             ,
             when
             we
             went
             on
             with
             the
             rest
             of
             the
             Experiment
             ,
             according
             to
             the
             way
             above
             describ'd
             ,
             we
             found
             ,
             by
             emptying
             the
             Receiver
             of
             air
             ,
             that
             we
             were
             able
             to
             raise
             the
             Quicksilver
             in
             the
             Cane
             30.
             inches
             ,
             or
             somewhat
             more
             above
             that
             in
             the
             viol
             .
          
           
             III.
             Sometimes
             it
             may
             happen
             ,
             that
             the
             Mercury
             ,
             when
             taken
             very
             soon
             out
             of
             the
             Receiver
             ,
             will
             not
             appear
             to
             have
             subsided
             to
             its
             first
             lownesse
             ,
             which
             perhaps
             't
             will
             not
             sink
             to
             in
             some
             while
             after
             :
             which
             is
             not
             to
             be
             wondred
             at
             ,
             since
             in
             such
             a
             Receiver
             ,
             
             which
             contains
             but
             little
             air
             ,
             the
             heat
             of
             the
             Cement
             and
             the
             iron
             ,
             imploy'd
             to
             melt
             it
             quite
             round
             the
             Receiver
             ,
             may
             impart
             a
             little
             warmth
             to
             the
             air
             in
             the
             viol
             ,
             which
             will
             after
             return
             to
             its
             former
             Temper
             .
             But
             this
             Accident
             is
             neither
             constant
             nor
             necessary
             to
             the
             Experiment
             .
          
           
             IV.
             T
             is
             very
             remarkable
             ,
             that
             if
             the
             Receiver
             be
             fitly
             stopt
             ,
             and
             slender
             enough
             ;
             upon
             the
             turning
             of
             the
             Stop-cock
             ,
             to
             let
             out
             the
             air
             at
             the
             first
             exuction
             ,
             the
             Mercury
             will
             be
             impell'd
             up
             by
             the
             spring
             of
             the
             Air
             in
             the
             viol
             ,
             suddenly
             flying
             abroad
             or
             stretching
             it self
             ,
             so
             that
             it
             will
             be
             rais'd
             several
             inches
             above
             the
             height
             it
             will
             rest
             at
             afterwards
             ,
             and
             will
             make
             several
             vibrations
             up
             and
             down
             before
             it
             come
             to
             settle
             ,
             just
             as
             the
             Mercury
             does
             in
             the
             Torricellian
             Experiment
             ,
             (
             the
             bare
             pressure
             of
             the
             little
             air
             doing
             here
             to
             the
             Mercury
             ,
             what
             the
             weight
             of
             the
             Atmosphere
             does
             there
             ,
             )
             and
             such
             motions
             of
             the
             Mercury
             will
             be
             made
             four
             or
             five
             subsequent
             Exuctions
             ,
             upon
             the
             withdrawing
             of
             the
             air
             in
             the
             Receiver
             .
             But
             as
             these
             grow
             lesser
             and
             lesser
             ,
             as
             the
             Spring
             of
             the
             included
             Air
             grows
             fainter
             ,
             so
             none
             of
             them
             is
             any
             thing
             near
             so
             considerable
             as
             the
             vibrations
             made
             upon
             the
             first
             Suck
             .
          
           
             V.
             Agreeable
             hereunto
             we
             observ'd
             ,
             that
             at
             the
             first
             Exuction
             ,
             when
             the
             Spring
             of
             the
             included
             Air
             was
             yet
             strong
             ,
             the
             Mercury
             would
             be
             rais'd
             by
             our
             Estimate
             above
             half
             ,
             if
             not
             ⅔
             of
             the
             whole
             height
             ,
             whereto
             't
             will
             at
             length
             be
             brought
             ,
             (
             though
             that
             must
             be
             according
             to
             the
             bignes
             of
             the
             Receiver
             ,
             and
             other
             circumstances
             ,
             )
             and
             the
             subsequent
             Exuctions
             do
             still
             adde
             less
             and
             less
             proportions
             of
             height
             to
             the
             Mercurial
             Cylinder
             ,
             and
             that
             for
             two
             Reasons
             :
             the
             one
             ,
             because
             the
             more
             there
             is
             of
             Mercury
             impell'd
             into
             the
             Tube
             ,
             the
             greater
             weight
             of
             Mercury
             presses
             upon
             the
             included
             air
             :
             and
             the
             other
             ,
             because
             the
             air
             has
             so
             much
             the
             more
             room
             in
             the
             viol
             to
             expand
             it self
             ,
             whereby
             its
             spring
             must
             be
             proportionably
             weakned
             .
          
           
             Lastly
             ,
             when
             we
             made
             most
             of
             these
             Tryals
             ,
             I
             had
             the
             curiosity
             to
             observe
             the
             height
             of
             the
             Mercury
             in
             a
             good
             Barometer
             ,
             and
             thereby
             found
             ,
             that
             the
             Air
             was
             then
             but
             light
             ;
             its
             greatest
             
             height
             reaching
             but
             to
             29
             inches
             ,
             and
             ⅜
             ,
             and
             its
             height
             soon
             after
             the
             Tryal
             ,
             whereof
             D
             r
             Wallis
             was
             a
             witnesse
             ,
             amounting
             but
             to
             29.
             inches
             .
          
           
             To
             make
             an
             estimate
             of
             the
             Quantity
             of
             Air
             ,
             that
             had
             rais'd
             the
             Quicksilver
             to
             27
             inches
             ,
             we
             took
             the
             viol
             that
             was
             imploy'd
             about
             this
             Experiment
             ;
             and
             having
             counterpois'd
             it
             ,
             whilst
             it
             was
             empty
             ,
             we
             afterward
             fill'd
             it
             with
             water
             ,
             and
             found
             the
             Liquor
             to
             weigh
             5.
             
             Ounces
             ,
             2.
             
             Drachms
             ,
             and
             about
             20.
             
             Grains
             ;
             and
             then
             having
             pour'd
             out
             the
             water
             ,
             till
             it
             was
             sunk
             to
             a
             mark
             which
             we
             had
             made
             on
             the
             outside
             of
             the
             Glass
             ,
             to
             take
             notice
             how
             high
             the
             Quick-silver
             reach'd
             that
             we
             pour'd
             in
             :
             and
             lastly
             ,
             weighing
             the
             remaining
             water
             ,
             equal
             in
             bulk
             to
             the
             Quick-silver
             ,
             we
             found
             it
             to
             amount
             to
             1.
             
             Ounce
             ,
             2.
             
             Drachms
             ,
             14.
             
             Grains
             ;
             so
             that
             the
             air
             ,
             that
             had
             rais'd
             up
             the
             Mercury
             ,
             possess'd
             (
             before
             its
             Expansion
             )
             in
             the
             viol
             the
             place
             but
             of
             4.
             ounces
             ,
             and
             a
             few
             odde
             grains
             ,
             
               i.
               e.
            
             of
             about
             ¼
             of
             a
             Pint
             of
             water
             .
             And
             as
             for
             the
             Pipe
             also
             ,
             imploy'd
             about
             the
             same
             Experiment
             ,
             we
             found
             its
             Cavity
             to
             have
             about
             ⅛
             part
             of
             an
             Inch
             in
             Diameter
             .
          
           
             It
             was
             one
             of
             the
             Uses
             I
             hop'd
             to
             make
             of
             this
             Experiment
             ,
             that
             by
             comparing
             the
             several
             degrees
             of
             Expansion
             of
             air
             included
             in
             the
             viol
             ,
             with
             the
             respective
             and
             increasing
             heights
             of
             the
             Mercury
             that
             was
             impell'd
             up
             into
             the
             Pipe
             ,
             some
             estimate
             might
             be
             made
             of
             the
             force
             of
             the
             Spring
             of
             the
             Air
             weaken'd
             by
             several
             degrees
             of
             Dilatation
             ;
             but
             for
             want
             of
             conveniences
             I
             forbore
             to
             venter
             upon
             such
             nice
             Observations
             ,
             especially
             because
             the
             Pressure
             of
             the
             dilated
             air
             ,
             that
             remains
             in
             the
             Receiver
             ,
             and
             is
             external
             to
             the
             air
             included
             in
             the
             viol
             ,
             must
             also
             be
             taken
             into
             consideration
             .
          
           
             Another
             Use
             of
             our
             Experiment
             may
             be
             this
             :
             That
             it
             may
             supply
             us
             with
             a
             considerable
             Argument
             against
             some
             Learned
             men
             ,
             who
             attribute
             the
             suspension
             of
             the
             Quick-silver
             in
             the
             Torricellian
             Experiment
             to
             a
             certain
             rarify'd
             matter
             ,
             which
             some
             call
             a
             Funiculus
             ,
             and
             whereto
             others
             give
             other
             names
             ;
             which
             rarify'd
             substance
             they
             suppose
             to
             draw
             up
             and
             sustain
             the
             Quick-silver
             ,
             
             in
             compliance
             of
             Natures
             abhorrency
             of
             a
             Vacuum
             .
             For
             in
             the
             Experiment
             under
             consideration
             ,
             the
             Quick-silver
             being
             not
             onely
             sustain'd
             at
             the
             height
             of
             27
             inches
             in
             the
             Tube
             ,
             but
             elevated
             thither
             ;
             if
             the
             cause
             of
             This
             be
             demanded
             ,
             it
             will
             be
             answer'd
             ,
             according
             to
             their
             hypothesis
             ,
             that
             the
             air
             in
             the
             Receiver
             ,
             external
             to
             that
             of
             the
             Viol
             ,
             being
             ,
             by
             reason
             of
             the
             sucking
             out
             of
             some
             of
             it
             by
             the
             Pump
             ,
             more
             rarified
             than
             that
             in
             the
             viol
             ,
             it
             draws
             up
             to
             it
             the
             Quick-silver
             in
             the
             Cane
             ,
             and
             the
             more
             it
             is
             rarify'd
             ,
             the
             higher
             it
             is
             enabl'd
             to
             draw
             it
             .
             But
             then
             I
             demand
             ,
             whence
             it
             comes
             to
             pass
             ,
             that
             though
             we
             can
             ,
             by
             persevering
             to
             pump
             ,
             more
             and
             more
             rarifie
             the
             little
             remaining
             air
             ,
             or
             the
             Aëreal
             substance
             in
             the
             Receiver
             ,
             That
             in
             the
             viol
             not
             appearing
             to
             be
             also
             rarified
             ,
             yet
             the
             air
             in
             the
             Receiver
             does
             not
             by
             virtue
             of
             its
             superadded
             rarefaction
             ,
             whereby
             it
             exceeds
             that
             of
             the
             air
             in
             the
             viol
             ,
             pull
             up
             the
             Quick-silver
             to
             a
             greater
             height
             in
             the
             Tube
             then
             27.
             inches
             :
             For
             ,
             that
             this
             is
             not
             the
             greatest
             height
             ,
             to
             which
             Mercury
             may
             be
             rais'd
             by
             this
             rarefy'd
             substance
             ,
             our
             Adversaries
             must
             not
             deny
             ,
             who
             tell
             us
             ,
             that
             in
             the
             Torricellian
             Experiment
             it
             sustains
             a
             Mercurial
             Cylinder
             of
             29.
             inches
             ,
             and
             ½
             ,
             and
             can
             raise
             a
             Cylinder
             of
             29
             inches
             to
             29
             ½
             ,
             or
             higher
             ,
             in
             case
             that
             the
             Cylinder
             be
             made
             to
             vibrate
             up
             and
             down
             in
             the
             Tube
             .
          
           
             And
             as
             for
             those
             ,
             
             that
             will
             in
             such
             cases
             ,
             as
             our
             Experiment
             suggests
             ,
             have
             recourse
             onely
             to
             that
             which
             they
             call
             the
             
               Fuga
               Vacui
            
             ,
             they
             may
             please
             also
             to
             consider
             ,
             that
             since
             the
             Quick-silver
             remains
             the
             same
             ,
             its
             ascension
             in
             the
             Tube
             will
             not
             be
             available
             for
             what
             they
             think
             to
             be
             Natures
             purpose
             ;
             for
             ,
             whether
             it
             reach
             higher
             or
             lower
             in
             the
             Tube
             ,
             it
             will
             adaequately
             fill
             no
             more
             space
             in
             one
             posture
             ,
             or
             in
             one
             figure
             ,
             then
             in
             another
             ,
             in
             what
             part
             soever
             of
             the
             cavity
             of
             the
             Receiver
             it
             be
             plac'd
             .
          
        
         
           
           
             EXPERIMENT
             II.
             
          
           
             Shewing
             ,
             that
             much
             included
             Air
             rais'd
             Mercury
             in
             an
             open
             Tube
             ,
             no
             higher
             than
             the
             weight
             of
             the
             Atmosphere
             may
             in
             a
             Baroscope
             .
          
           
             IN
             the
             former
             Experiment
             ,
             by
             reason
             of
             the
             smalness
             of
             the
             viol
             ,
             that
             was
             employ'd
             about
             it
             ,
             there
             was
             so
             little
             Air
             included
             ,
             that
             the
             Expansion
             of
             it
             so
             far
             ,
             as
             was
             requisite
             to
             impell
             up
             the
             Mercury
             in
             the
             Pipe
             to
             the
             above
             mentioned
             height
             of
             27.
             inches
             ,
             may
             be
             probably
             suspected
             to
             have
             very
             much
             weaken'd
             its
             Spring
             ,
             and
             therefore
             it
             may
             be
             thought
             ,
             that
             (
             especially
             considering
             the
             great
             force
             that
             several
             of
             our
             Experiments
             manifest
             imprison'd
             air
             to
             have
             ,
             )
             if
             there
             were
             a
             greater
             Quantity
             of
             air
             included
             in
             the
             vessel
             ,
             so
             that
             the
             Expansion
             ,
             sufficient
             to
             raise
             the
             Mercury
             to
             the
             former
             height
             ,
             would
             not
             need
             to
             be
             considerable
             ,
             (
             because
             that
             the
             capacity
             of
             the
             Tube
             being
             but
             the
             same
             ,
             the
             whole
             included
             air
             will
             be
             so
             much
             the
             lesse
             expanded
             ,
             by
             how
             much
             the
             more
             of
             it
             there
             is
             ,
             )
             it
             seem'd
             probable
             that
             the
             Spring
             of
             the
             Air
             ,
             being
             but
             a
             little
             weakned
             by
             so
             small
             a
             dilatation
             ,
             would
             remain
             strong
             enough
             to
             raise
             a
             much
             taller
             Cylinder
             of
             Mercury
             in
             the
             Tube
             ,
             and
             perhaps
             make
             the
             Liquor
             run
             over
             into
             the
             Receiver
             .
          
           
             But
             though
             this
             Suggestion
             seem
             probable
             enough
             ,
             yet
             when
             I
             consider'd
             ,
             that
             the
             weight
             of
             the
             Atmosphere
             is
             able
             to
             sustain
             a
             Cylinder
             of
             Quick-silver
             but
             of
             30.
             inches
             ,
             or
             thereabouts
             ,
             (
             in
             perpendicular
             height
             ,
             )
             and
             consequently
             that
             the
             pressure
             of
             such
             a
             Mercurial
             Cylinder
             is
             equivalent
             to
             that
             of
             an
             Atmospherical
             Cylinder
             of
             the
             same
             bore
             ;
             't
             was
             not
             difficult
             to
             conclude
             ,
             that
             since
             the
             Air
             in
             a
             viol
             ,
             before
             the
             mouth
             is
             clos'd
             ,
             has
             a
             Spring
             but
             equal
             in
             strength
             to
             the
             weight
             of
             the
             Atmospherical
             Pillar
             that
             leans
             upon
             it
             ,
             (
             for
             if
             the
             Spring
             were
             too
             strong
             for
             the
             weight
             that
             leans
             on
             it
             ,
             some
             of
             the
             air
             would
             get
             out
             of
             the
             viol
             ,
             )
             a
             greater
             viol
             ,
             and
             consequently
             a
             greater
             quantity
             of
             included
             air
             would
             
             not
             be
             able
             by
             its
             spring
             to
             elevate
             and
             sustain
             a
             longer
             Cylinder
             of
             Mercury
             ,
             than
             the
             weight
             of
             the
             Atmosphere
             is
             able
             to
             do
             ;
             nor
             indeed
             altogether
             so
             much
             ,
             because
             of
             some
             little
             (
             though
             but
             little
             )
             Diminution
             of
             the
             Spring
             by
             some
             (
             though
             but
             a
             small
             )
             expansion
             ,
             that
             the
             included
             Air
             suffers
             ,
             by
             succeeding
             in
             the
             place
             of
             the
             Mercury
             ,
             that
             is
             impell'd
             up
             .
          
           
             To
             clear
             therefore
             this
             matter
             by
             an
             Experiment
             ,
             we
             took
             a
             strong
             glass-bottle
             ,
             capable
             of
             holding
             about
             a
             Quart
             of
             Liquor
             ,
             and
             having
             put
             into
             it
             a
             convenient
             quantity
             of
             Quick-silver
             ,
             we
             erected
             in
             it
             a
             very
             long
             and
             slender
             pipe
             of
             Glass
             ,
             open
             at
             both
             the
             ends
             ,
             and
             reaching
             at
             the
             lower
             end
             beneath
             the
             surface
             of
             the
             stagnant
             Mercury
             ,
             and
             having
             fasten'd
             this
             pipe
             in
             the
             neck
             of
             the
             Bottle
             ,
             by
             choaking
             up
             that
             neck
             very
             accurately
             with
             good
             Cement
             ,
             that
             none
             of
             the
             included
             air
             might
             be
             able
             to
             get
             out
             ,
             we
             conveigh'd
             the
             whole
             into
             a
             Receiver
             ,
             like
             that
             imploy'd
             about
             the
             I.
             Experiment
             in
             shape
             ,
             but
             much
             larger
             ,
             that
             it
             might
             be
             able
             to
             contain
             so
             great
             a
             vessel
             ;
             and
             then
             the
             Engine
             being
             set
             a
             work
             ,
             we
             quickly
             rais'd
             the
             Quick-silver
             to
             a
             greater
             height
             than
             formerly
             ,
             and
             when
             we
             saw
             it
             come
             to
             a
             stand
             ,
             we
             did
             by
             the
             help
             of
             some
             marks
             ,
             made
             before
             hand
             on
             the
             pipe
             ,
             and
             by
             the
             help
             of
             a
             very
             long
             and
             well
             divided
             Ruler
             ,
             measure
             ,
             with
             as
             much
             care
             and
             accurateness
             as
             the
             figure
             of
             the
             vessels
             would
             allow
             us
             to
             do
             ,
             the
             height
             of
             the
             Mercurial
             Cylinder
             ,
             which
             we
             found
             to
             be
             29.
             inches
             ,
             and
             about
             ⅞
             ,
             to
             which
             abating
             half
             an
             inch
             ,
             which
             was
             rais'd
             ,
             before
             the
             Pump
             was
             employed
             ,
             by
             some
             air
             that
             had
             been
             blow'd
             into
             the
             Bottle
             ,
             to
             try
             whether
             it
             were
             stanch
             ;
             deducting
             ,
             I
             say
             ,
             this
             half
             Inch
             of
             Quick-silver
             ,
             which
             remain'd
             in
             the
             Tube
             after
             the
             external
             Air
             was
             let
             in
             ,
             (
             as
             well
             as
             it
             had
             been
             there
             before
             the
             Receiver
             was
             exhausted
             ,
             )
             out
             of
             the
             newly
             mention'd
             number
             there
             remain'd
             29.
             inches
             ,
             and
             neer
             ⅜
             ,
             for
             the
             height
             of
             the
             Mercury
             ,
             rais'd
             by
             the
             Spring
             of
             the
             Air
             ,
             shut
             up
             in
             the
             Bottle
             :
             and
             then
             consulting
             with
             the
             above
             mentioned
             Baroscope
             ,
             which
             stood
             in
             a
             window
             in
             another
             part
             of
             the
             house
             ,
             I
             found
             ,
             that
             the
             weight
             of
             the
             Atmosphere
             did
             bear
             a
             Mercurial
             Cylinder
             of
             about
             29.
             
             
             Inches
             and
             ½
             ,
             which
             was
             higher
             by
             ⅛
             than
             that
             to
             which
             the
             Spring
             had
             rais'd
             the
             Quick-silver
             in
             the
             exhausted
             Receiver
             :
             and
             the
             Difference
             perhaps
             would
             have
             been
             greater
             ,
             if
             the
             place
             ,
             where
             the
             Experiment
             was
             made
             ,
             had
             not
             by
             its
             warmth
             added
             some
             little
             matter
             to
             the
             Spring
             of
             the
             Air
             ,
             and
             if
             also
             we
             could
             have
             kept
             the
             Mercury
             so
             long
             elevated
             ,
             as
             to
             give
             it
             leave
             to
             discharge
             its
             self
             of
             those
             small
             bubbles
             ,
             which
             t
             is
             almost
             impossible
             in
             such
             Experiments
             as
             this
             to
             free
             Quick-silver
             from
             ,
             without
             some
             help
             from
             time
             .
          
           
             Lastly
             ,
             though
             we
             caus'd
             the
             Pump
             to
             be
             ply'd
             ,
             to
             try
             whether
             we
             could
             not
             ,
             by
             the
             more
             diligent
             Exuction
             of
             the
             Receiver
             ,
             raise
             the
             Quick-silver
             above
             the
             height
             of
             that
             which
             the
             Atmosphere
             kept
             sustain'd
             in
             the
             Baroscope
             ,
             yet
             our
             labour
             gave
             us
             but
             a
             confirmation
             ,
             that
             the
             Spring
             of
             the
             Air
             would
             not
             raise
             the
             Mercury
             higher
             ,
             then
             did
             the
             weight
             of
             the
             Atmosphere
             ,
             which
             may
             not
             a
             little
             confirm
             the
             2
             d
             Observation
             .
          
           
             N
             B.
             This
             was
             not
             the
             onely
             nor
             the
             first
             Experiment
             we
             made
             of
             this
             kind
             ,
             but
             this
             being
             carried
             on
             without
             mischances
             ,
             (
             with
             which
             divers
             others
             were
             attended
             ,
             )
             and
             made
             with
             much
             care
             ,
             I
             thought
             fit
             to
             set
             down
             This
             in
             stead
             of
             all
             ,
             intimating
             generally
             about
             the
             rest
             ,
             that
             they
             seem'd
             to
             agree
             well
             for
             the
             main
             with
             that
             ,
             which
             is
             here
             recited
             ;
             onely
             there
             is
             one
             thing
             relating
             to
             those
             other
             Experiments
             ,
             that
             seems
             not
             altogether
             unworthy
             to
             be
             taken
             notice
             of
             ;
             which
             is
             ,
             that
             when
             our
             Tryals
             were
             made
             in
             vessels
             ,
             that
             contain'd
             a
             considerable
             quantity
             of
             Air
             ,
             though
             upon
             the
             exhaustion
             of
             the
             Receiver
             the
             Spring
             of
             the
             included
             Air
             could
             not
             raise
             the
             Quick-silver
             to
             the
             top
             of
             the
             pipe
             ,
             yet
             sometimes
             by
             other
             Effects
             it
             manifested
             it self
             to
             be
             very
             strong
             ,
             as
             once
             or
             twice
             by
             the
             blowing
             out
             or
             breaking
             the
             Cork
             or
             Cement
             ,
             and
             other
             matter
             that
             was
             imploy'd
             to
             stop
             the
             Glass
             it
             was
             shut
             in
             ;
             and
             once
             by
             an
             Accident
             too
             memorable
             to
             be
             here
             past
             over
             in
             silence
             .
          
           
             I
             had
             one
             day
             invited
             D
             r
             Wallis
             to
             see
             such
             an
             Experiment
             as
             I
             have
             been
             relating
             ,
             made
             with
             (
             not
             a
             viol
             ,
             but
             )
             a
             bottle
             of
             Green
             
             Glass
             ,
             (
             such
             as
             we
             use
             now
             for
             Wine
             ,
             )
             and
             4
             or
             5
             pounds
             of
             Mercury
             .
             After
             this
             Learned
             Person
             and
             I
             had
             continued
             Spectators
             as
             long
             as
             we
             thought
             fit
             ,
             we
             withdrew
             into
             another
             Room
             ,
             where
             we
             had
             not
             sat
             long
             by
             the
             fire
             ,
             before
             we
             were
             surpriz'd
             by
             a
             suddain
             noise
             ,
             which
             the
             person
             ,
             that
             occasion'd
             it
             ,
             presently
             came
             running
             in
             to
             give
             us
             an
             account
             of
             ,
             by
             which
             it
             appear'd
             ,
             that
             this
             Ingenious
             young
             Man
             ,
             (
             whom
             I
             often
             imploy
             about
             Pneumatical
             Experiments
             ,
             and
             whom
             I
             mention'd
             to
             Your
             Lordship
             ,
             because
             
               I.
               M.
            
             has
             the
             honour
             to
             be
             somewhat
             known
             to
             You
             ,
             )
             being
             desirous
             in
             our
             absence
             to
             satisfie
             the
             Curiosity
             he
             had
             to
             know
             ,
             whether
             the
             Quick-silver
             could
             not
             be
             rais'd
             higher
             in
             the
             pipe
             than
             I
             had
             foretold
             ,
             plyed
             the
             Pump
             so
             obstinately
             ,
             that
             at
             length
             ,
             the
             Bottle
             being
             not
             ,
             it
             seems
             ,
             every
             where
             equally
             strong
             ,
             the
             imprison'd
             air
             found
             it
             more
             difficult
             to
             make
             the
             Quick-silver
             run
             over
             at
             the
             top
             of
             the
             pipe
             ,
             than
             to
             break
             the
             Bottle
             in
             the
             weakest
             place
             ,
             and
             accordingly
             did
             not
             onely
             throw
             off
             a
             piece
             of
             the
             Bottle
             ,
             but
             threw
             it
             with
             such
             violence
             against
             the
             large
             and
             strong
             Receiver
             ,
             as
             broke
             that
             also
             ,
             and
             render'd
             it
             unserviceable
             for
             the
             future
             .
             But
             the
             Doctor
             and
             I
             laying
             together
             the
             Pipe
             ,
             which
             happen'd
             to
             be
             broken
             into
             but
             few
             pieces
             ,
             concluded
             by
             the
             place
             ,
             to
             which
             we
             were
             told
             it
             reacht
             when
             this
             Accident
             happened
             ,
             that
             it
             had
             not
             exceeded
             ,
             nor
             indeed
             fully
             equall'd
             the
             height
             ,
             to
             which
             the
             weight
             of
             the
             Atmosphere
             might
             have
             rais'd
             it
             .
          
        
         
           
             EXPERIMENT
             III.
             
          
           
             Shewing
             that
             the
             Spring
             of
             the
             included
             Air
             will
             raise
             Mercury
             to
             almost
             equal-heights
             in
             very
             unequal
             Tubes
             .
          
           
             HAving
             shown
             in
             the
             two
             former
             Experiments
             ,
             that
             the
             Active
             strength
             of
             the
             Airs
             Spring
             is
             very
             considerable
             ,
             I
             thought
             good
             also
             to
             examine
             ,
             whether
             or
             no
             to
             the
             other
             resemblances
             
             in
             operation
             between
             the
             weight
             of
             the
             free
             Air
             ,
             and
             the
             pressure
             of
             the
             included
             Air
             ,
             this
             also
             may
             be
             added
             ,
             that
             as
             the
             gravitation
             of
             the
             Atmosphere
             is
             able
             (
             as
             we
             shall
             hereafter
             prove
             )
             to
             sustain
             the
             Mercury
             at
             the
             same
             height
             in
             lesser
             and
             greater
             Tubes
             ,
             seal'd
             at
             the
             top
             ;
             so
             the
             Pressure
             of
             the
             included
             Air
             may
             be
             able
             to
             sustain
             the
             Mercury
             at
             the
             same
             height
             in
             slenderer
             and
             in
             larger
             Tubes
             ,
             though
             in
             the
             latter
             it
             must
             sustain
             a
             far
             greater
             weight
             of
             Mercury
             than
             in
             the
             former
             ;
             provided
             allowance
             be
             made
             for
             the
             weakning
             ,
             which
             the
             Spring
             of
             the
             included
             Air
             must
             be
             subject
             to
             ,
             by
             reason
             that
             ,
             to
             succeed
             in
             the
             place
             of
             a
             large
             Cylinder
             of
             Mercury
             impell'd
             up
             into
             the
             greater
             Tube
             ,
             it
             must
             expand
             it self
             more
             ,
             and
             consequently
             have
             its
             Spring
             more
             weakned
             ,
             than
             if
             the
             Tube
             were
             slender
             .
          
           
             To
             prosecute
             this
             Experiment
             ,
             I
             thought
             on
             a
             peculiar
             shape
             of
             vessels
             ,
             which
             ,
             if
             I
             had
             been
             where
             there
             is
             a
             Glass-house
             ,
             I
             would
             have
             caus'd
             to
             be
             blown
             for
             the
             more
             convenient
             trying
             of
             two
             Pipes
             of
             different
             bores
             at
             the
             same
             time
             .
             But
             though
             I
             wanted
             this
             Accommodation
             ,
             I
             thought
             I
             might
             well
             enough
             show
             what
             I
             intended
             by
             imploying
             successively
             two
             Tubes
             of
             very
             differing
             sizes
             ,
             provided
             the
             vessel
             for
             the
             including
             of
             the
             Air
             were
             the
             same
             .
          
           
             Wherefore
             taking
             the
             Glass
             bottle
             ,
             made
             use
             of
             to
             try
             the
             former
             Experiment
             ,
             and
             erecting
             in
             it
             after
             the
             manner
             above
             described
             a
             Cylindrical
             pipe
             of
             Glass
             ,
             a
             good
             deal
             larger
             than
             the
             former
             ,
             (
             if
             not
             as
             large
             agen
             ,
             )
             we
             prosecuted
             the
             Experiment
             as
             we
             had
             made
             it
             ,
             with
             the
             slender
             Tube
             above
             mentioned
             ,
             and
             found
             that
             we
             were
             able
             ,
             by
             the
             Spring
             of
             the
             Air
             in
             the
             bottle
             ,
             to
             raise
             the
             Quick-silver
             to
             a
             considerable
             height
             ,
             which
             ,
             measuring
             as
             well
             as
             the
             vessel
             would
             allow
             us
             ,
             was
             ,
             by
             the
             least
             estimate
             that
             was
             made
             of
             it
             ,
             (
             which
             was
             mine
             )
             28.
             inches
             ,
             and
             ⅛
             ,
             by
             which
             it
             appear'd
             to
             want
             somewhat
             above
             an
             Inch
             of
             the
             height
             of
             the
             Mercurial
             Cylinder
             ,
             which
             the
             weight
             of
             the
             Atmosphere
             could
             have
             sustain'd
             ,
             as
             appear'd
             by
             the
             Barometer
             ,
             wherein
             the
             Quick-silver
             at
             that
             time
             was
             about
             29.
             inches
             ,
             and
             ¼
             high
             ;
             which
             difference
             
             was
             no
             more
             then
             I
             expected
             ,
             considering
             that
             ,
             whereas
             the
             weight
             of
             the
             Atmosphere
             is
             still
             the
             same
             when
             the
             Mercury
             is
             at
             its
             full
             height
             (
             and
             that
             whether
             the
             Pipe
             be
             great
             or
             small
             )
             in
             a
             seal'd
             Tube
             ;
             the
             Spring
             of
             our
             included
             Air
             must
             needs
             be
             weakned
             the
             larger
             the
             Tube
             is
             ,
             and
             the
             higher
             the
             liquid
             Metal
             is
             impell'd
             in
             it
             ,
             so
             that
             it
             seem'd
             a
             considerable
             Phaenomenon
             ,
             that
             the
             Spring
             of
             so
             little
             Air
             should
             be
             able
             to
             raise
             the
             Mercury
             as
             high
             within
             an
             Inch
             or
             thereabouts
             in
             a
             wider
             as
             in
             a
             slenderer
             Tube
             ,
             since
             the
             Diameter
             of
             the
             Cavity
             of
             the
             former
             being
             by
             our
             estimate
             double
             to
             that
             of
             the
             latter
             ,
             (
             into
             which
             the
             slender
             Pipe
             could
             easily
             be
             put
             
               as
               into
            
             a
             Case
             too
             big
             for
             it
             :
             )
             The
             greater
             Mercurial
             Cylinder
             may
             be
             suppos'd
             to
             have
             weighed
             near
             four
             times
             as
             much
             as
             the
             lesser
             ;
             I
             say
             ,
             near
             ,
             because
             there
             was
             an
             Inch
             difference
             in
             their
             heights
             :
             but
             in
             case
             these
             had
             been
             equal
             ,
             then
             the
             Solidities
             of
             the
             Cylinders
             would
             have
             been
             to
             one
             another
             as
             their
             Bases
             ;
             and
             since
             these
             ,
             being
             Circular
             ,
             are
             in
             duplicate
             proportion
             to
             their
             Diameters
             ,
             that
             is
             ,
             as
             the
             Squares
             of
             their
             Diameters
             ;
             its
             plain
             ,
             that
             if
             the
             Diameters
             be
             as
             one
             to
             two
             ,
             the
             Squares
             of
             them
             must
             be
             as
             one
             to
             four
             ;
             and
             these
             Cylinders
             consisting
             of
             the
             same
             Mercury
             ,
             their
             Weights
             will
             have
             the
             same
             Proportions
             with
             their
             Solidities
             ,
             and
             consequently
             would
             be
             as
             one
             to
             four
             ,
             making
             the
             abatement
             formerly
             intimated
             for
             the
             Inch
             and
             a
             little
             more
             of
             Mercury
             ,
             by
             which
             the
             larger
             Cylinder
             came
             short
             of
             the
             height
             of
             the
             former
             .
          
           
             NB.
             1.
             
             This
             and
             the
             two
             former
             Experiments
             tryed
             by
             us
             with
             Quick-silver
             ,
             may
             be
             also
             tryed
             with
             Water
             ;
             but
             besides
             that
             we
             could
             hardly
             procure
             Tubes
             long
             enough
             for
             such
             Tryals
             ,
             we
             were
             not
             very
             sollicitous
             about
             it
             :
             for
             if
             we
             attentively
             enough
             consider
             ,
             what
             has
             been
             already
             deliver'd
             ,
             and
             the
             Proportion
             in
             specifick
             gravity
             betwixt
             Water
             and
             Quick-silver
             ,
             (
             whereof
             the
             latter
             is
             near
             14.
             times
             as
             heavy
             ,
             bulk
             for
             bulk
             ,
             as
             the
             former
             ,
             )
             't
             will
             not
             be
             difficult
             to
             foresee
             the
             Event
             of
             such
             Experiments
             ,
             which
             he
             ,
             that
             has
             a
             mind
             to
             make
             ,
             should
             be
             furnish'd
             not
             onely
             with
             long
             Tubes
             ,
             but
             with
             capacious
             Vessels
             to
             shut
             up
             the
             Air
             in
             .
             
             Else
             the
             Air
             will
             be
             so
             far
             expanded
             before
             the
             Water
             has
             attain'd
             near
             the
             height
             ,
             to
             which
             the
             weight
             of
             the
             Atmosphere
             may
             raise
             it
             ,
             that
             the
             Experiments
             will
             not
             seem
             to
             succeed
             near
             so
             well
             with
             Water
             ,
             as
             ours
             did
             with
             Quick-silver
             .
          
           
             2.
             
             We
             thought
             it
             worth
             trying
             ,
             whether
             ,
             when
             the
             included
             Air
             had
             rais'd
             the
             great
             Cylinder
             of
             Mercury
             to
             the
             utmost
             height
             ,
             it
             could
             elevate
             it
             to
             ,
             by
             the
             Spring
             it
             then
             had
             ;
             it
             would
             not
             be
             brought
             to
             raise
             the
             Quick-silver
             yet
             higher
             ,
             if
             ,
             notwithstanding
             the
             Expansion
             it
             had
             already
             ,
             there
             were
             an
             agitation
             made
             by
             the
             heated
             Corpuscles
             of
             the
             same
             Air.
             And
             in
             pursuance
             of
             this
             Curiosity
             having
             caus'd
             an
             hot
             Iron
             and
             a
             Shovel
             of
             kindled
             Coals
             to
             be
             held
             near
             the
             opposite
             parts
             of
             the
             Receiver
             ,
             we
             perceiv'd
             after
             a
             while
             ,
             that
             the
             Mercury
             ascended
             ⅛
             of
             an
             inch
             or
             better
             above
             the
             greatest
             height
             it
             had
             reach'd
             before
             .
             But
             conjecturing
             that
             it
             would
             have
             risen
             higher
             ,
             were
             it
             not
             that
             whilst
             the
             application
             of
             the
             hot
             bodies
             was
             making
             ,
             some
             Particles
             of
             Air
             had
             unperceivably
             stolen
             into
             the
             Receiver
             ,
             I
             caus'd
             the
             Pump
             to
             be
             ply'd
             again
             to
             withdraw
             the
             Air
             ,
             I
             suspected
             to
             have
             got
             in
             ,
             by
             which
             means
             the
             Mercury
             was
             quickly
             rais'd
             ⅝
             of
             an
             inch
             ,
             (
             or
             better
             ,
             )
             by
             virtue
             of
             this
             Adventitious
             Spring
             ,
             (
             if
             I
             may
             so
             call
             it
             ,
             )
             which
             the
             included
             Air
             acquir'd
             by
             heat
             ,
             and
             I
             made
             no
             doubt
             ,
             that
             it
             might
             have
             been
             rais'd
             much
             higher
             ,
             but
             I
             was
             unwilling
             by
             applying
             a
             less
             moderate
             heat
             to
             hazard
             the
             breaking
             of
             my
             Glasses
             ,
             in
             the
             place
             I
             then
             was
             in
             ,
             where
             such
             a
             mischance
             could
             scarce
             have
             been
             repair'd
             .
          
        
         
           
             EXPERIMENT
             IV.
             
          
           
             About
             a
             new
             Hydraulo-pneumatical
             Fountain
             ,
             made
             by
             the
             Spring
             of
             uncompress'd
             Air.
             
          
           
             I
             Shall
             now
             add
             such
             an
             application
             of
             the
             Principle
             whereon
             the
             former
             Experiment
             was
             grounded
             ,
             as
             I
             should
             scarce
             think
             
             worth
             mentioning
             in
             this
             place
             ,
             were
             it
             not
             that
             besides
             that
             divers
             Virtuosi
             seem
             not
             a
             little
             delighted
             with
             it
             ,
             it
             may
             for
             ought
             I
             know
             prove
             to
             be
             of
             some
             Philosophical
             use
             (
             to
             be
             pointed
             at
             hereafter
             .
             )
          
           
             We
             took
             a
             Glass-bottle
             with
             a
             convenient
             quantity
             of
             Water
             in
             it
             ,
             and
             fitted
             this
             Bottle
             with
             a
             slender
             glass-pipe
             open
             at
             both
             ends
             ,
             and
             about
             three
             foot
             long
             ,
             which
             was
             so
             plac'd
             ,
             that
             the
             lower
             Orifice
             was
             a
             good
             way
             beneath
             the
             Surface
             of
             the
             Water
             ,
             and
             the
             Pipe
             it self
             passed
             perpendicularly
             upwards
             through
             the
             Neck
             of
             the
             Bottle
             ,
             which
             Neck
             was
             ,
             by
             the
             Pipe
             and
             by
             good
             hard
             Cement
             imploy'd
             to
             fill
             the
             space
             betwixt
             the
             Pipe
             and
             the
             inside
             ,
             so
             well
             and
             firmly
             clos'd
             ,
             that
             no
             Water
             or
             Air
             could
             get
             out
             of
             the
             bottle
             ,
             
             nor
             no
             externall
             Aire
             could
             get
             into
             it
             ,
             but
             by
             passing
             through
             the
             Pipe.
             This
             Instrument
             was
             convey'd
             into
             a
             large
             Receiver
             shap'd
             like
             a
             Pear
             ,
             of
             which
             a
             good
             part
             of
             the
             blunt
             end
             ,
             and
             a
             small
             part
             of
             the
             sharp
             end
             are
             cut
             off
             by
             Sections
             parallel
             to
             the
             Horizon
             ,
             and
             consequently
             to
             one
             another
             .
             And
             because
             this
             Receiver
             was
             not
             (
             nor
             ought
             to
             be
             )
             long
             enough
             to
             receive
             the
             whole
             Pipe
             ,
             there
             was
             Cemented
             on
             to
             the
             upper
             part
             of
             it
             a
             smaller
             Receiver
             of
             white
             Glass
             ,
             of
             such
             a
             length
             and
             bigness
             ,
             that
             the
             upper
             end
             of
             the
             Pipe
             might
             reach
             to
             the
             middle
             of
             its
             Cavity
             ,
             or
             thereabouts
             ,
             and
             that
             the
             motions
             of
             the
             springing
             water
             might
             have
             a
             convenient
             Scope
             ,
             and
             so
             be
             the
             better
             taken
             notice
             of
             .
          
           
             This
             double
             Receiver
             being
             cemented
             on
             to
             the
             Engine
             ,
             a
             little
             of
             the
             Air
             was
             by
             one
             Suck
             of
             the
             Pump
             drawn
             out
             from
             it
             ,
             by
             which
             the
             Pressure
             of
             the
             remaining
             Air
             being
             weakned
             ,
             it
             was
             necessary
             ,
             that
             since
             the
             Air
             included
             in
             the
             Bottle
             had
             not
             its
             Spring
             likewise
             weakned
             ,
             it
             should
             expand
             it self
             ,
             and
             consequently
             impell
             up
             the
             water
             in
             the
             same
             Bottle
             through
             the
             Pipe
             ,
             which
             it
             did
             so
             vigorously
             ,
             as
             to
             make
             it
             strike
             briskly
             at
             first
             against
             that
             part
             of
             the
             top
             of
             the
             smaller
             Receiver
             ,
             which
             was
             just
             over
             the
             Orifice
             of
             the
             Pipe.
             But
             after
             it
             had
             a
             while
             made
             the
             Water
             thus
             shoot
             up
             in
             a
             perpendicular
             line
             ,
             as
             the
             Spring
             of
             the
             Air
             in
             the
             Bottle
             grew
             by
             that
             Airs
             dilatation
             to
             be
             weaken'd
             ,
             the
             Water
             
             would
             be
             impell'd
             up
             less
             strongly
             and
             less
             directly
             ,
             till
             the
             Air
             in
             the
             Bottle
             being
             as
             much
             expanded
             as
             that
             in
             the
             Receiver
             ,
             the
             Ascent
             of
             the
             Water
             would
             quite
             cease
             ,
             unless
             by
             Pumping
             a
             little
             more
             Aire
             out
             of
             the
             Receiver
             we
             renew'd
             it
             again
             .
          
           
             About
             the
             making
             of
             this
             Experiment
             these
             Particulars
             may
             be
             noted
             .
          
           
             1.
             
             T
             is
             convenient
             ,
             that
             the
             upper
             part
             of
             the
             Pipe
             be
             made
             (
             as
             it
             easily
             may
             be
             at
             the
             flame
             of
             a
             Lamp
             )
             very
             slender
             ,
             that
             the
             Water
             having
             but
             a
             very
             small
             Orifice
             to
             issue
             out
             at
             ,
             may
             be
             spent
             but
             slowly
             ,
             and
             thereby
             make
             the
             Experiment
             last
             so
             much
             the
             longer
             .
          
           
             2.
             
             You
             may
             ,
             if
             you
             please
             ,
             in
             stead
             of
             making
             the
             upper
             part
             of
             the
             Pipe
             slender
             ,
             as
             was
             just
             now
             directed
             ,
             Cement
             on
             to
             it
             a
             Top
             either
             of
             Glass
             or
             Brass
             ,
             consisting
             of
             three
             or
             more
             very
             slender
             Pipes
             ,
             with
             a
             Pin-hole
             at
             the
             end
             of
             each
             ,
             that
             one
             of
             these
             pointing
             directly
             upwards
             ,
             and
             the
             others
             to
             the
             right
             hand
             and
             to
             the
             left
             ,
             the
             Water
             may
             spin
             out
             several
             ways
             at
             once
             ,
             by
             which
             kind
             of
             branched
             Pipes
             we
             have
             sometimes
             imitated
             the
             
               Jets
               d'
               eau
            
             (
             as
             the
             French
             call
             them
             )
             and
             Artificial
             fountains
             of
             Gardens
             and
             Groto's
             .
          
           
             3.
             
             In
             regard
             that
             so
             short
             a
             Cylinder
             of
             Water
             ,
             as
             exceeded
             not
             the
             length
             of
             our
             Glass
             pipe
             ,
             could
             not
             make
             any
             considerable
             resistance
             to
             the
             expansion
             of
             the
             included
             Air
             ,
             it
             was
             thought
             and
             found
             safe
             enough
             to
             imploy
             in
             stead
             of
             a
             strong
             Glass-bottle
             a
             much
             larger
             Viol
             ,
             without
             being
             sollicitous
             about
             its
             shape
             ,
             or
             that
             it
             should
             be
             very
             strong
             ,
             and
             by
             this
             means
             we
             could
             make
             this
             pleasant
             Spectacle
             last
             a
             great
             while
             ,
             especially
             if
             we
             also
             made
             use
             of
             the
             expedient
             to
             be
             mentioned
             in
             the
             following
             Note
             .
          
           
             4.
             
             If
             you
             find
             that
             the
             included
             Air
             have
             by
             expanding
             it self
             too
             much
             weaken'd
             its
             Spring
             ,
             whilst
             there
             yet
             remains
             with
             it
             a
             good
             quantity
             of
             Water
             in
             the
             Bottle
             or
             Viol
             ,
             you
             may
             reinforce
             the
             pressure
             of
             the
             Air
             by
             onely
             turning
             the
             Stop-cock
             ,
             and
             letting
             in
             what
             air
             you
             think
             fit
             to
             the
             exhausted
             Receiver
             :
             for
             upon
             the
             admission
             of
             this
             new
             Air
             ,
             the
             Air
             in
             the
             Receiver
             will
             press
             
             sisted
             on
             ?
             If
             as
             a
             Law-maker
             ,
             then
             even
             the
             Sanction
             will
             continue
             ,
             by
             which
             such
             Laws
             as
             these
             obliged
             formerly
             :
             So
             they
             will
             still
             oblige
             as
             Laws
             ,
             whilst
             the
             same
             reason
             continues
             for
             which
             God
             was
             at
             first
             pleas'd
             to
             impose
             them
             .
             If
             as
             an
             infallible
             Judge
             of
             Reason
             ;
             still
             it
             will
             follow
             ,
             that
             whilst
             the
             Reason
             holds
             ,
             they
             will
             be
             so
             far
             from
             being
             made
             unlawful
             in
             such
             Particulars
             wherein
             the
             Reason
             does
             indeed
             hold
             ,
             that
             their
             performance
             will
             still
             be
             acceptable
             to
             God
             ,
             tho'
             not
             commanded
             by
             him
             .
             Either
             way
             of
             Explication
             is
             sufficient
             to
             overthrow
             his
             whole
             way
             of
             reasoning
             ,
             as
             manag'd
             by
             our
             Adversaries
             .
          
           
             But
             what
             if
             we
             should
             turn
             this
             way
             of
             reasoning
             us'd
             by
             the
             Apostles
             ,
             
             against
             our
             Adversaries
             ?
             What
             if
             we
             should
             conclude
             ,
             That
             because
             
               Instrumental
               Musick
            
             was
             us'd
             then
             in
             their
             
               Temple
               Sacrifices
            
             ,
             therefore
             it
             should
             still
             be
             at
             least
             fit
             and
             acceptable
             in
             our
             present
             
               Eucharistical
               Sacrifices
            
             ?
             I
             cannot
             foresee
             what
             they
             could
             say
             ,
             why
             we
             should
             not
             have
             reason'd
             as
             the
             Apostles
             did
             ;
             or
             how
             the
             Apostles
             could
             blame
             us
             for
             doing
             so
             ;
             or
             why
             our
             Adversaries
             should
             blame
             us
             ;
             who
             profess
             themselves
             such
             Enemies
             of
             Impositions
             ,
             if
             they
             did
             not
             impose
             upon
             us
             more
             than
             the
             Apostles
             ,
             in
             so
             easily
             condemning
             matters
             of
             this
             nature
             as
             unlawful
             .
             They
             can
             pretend
             no
             more
             condemnation
             in
             other
             places
             of
             the
             Writings
             of
             the
             Apostles
             in
             this
             Case
             ,
             than
             in
             those
             others
             wherein
             the
             Apostles
             themselves
             allow
             this
             way
             of
             Arguing
             .
             And
             I
             know
             no
             reason
             from
             the
             natures
             of
             the
             things
             themselves
             ,
             that
             even
             our
             Adversaries
             can
             pretend
             to
             be
             temporary
             ,
             or
             that
             will
             not
             make
             Instrumental-Musick
             as
             suitable
             to
             our
             present
             Worship
             ,
             as
             it
             was
             to
             that
             of
             the
             Apostles
             .
             No
             sort
             of
             Sacrifices
             were
             more
             proper
             for
             Hymns
             than
             those
             that
             are
             Eucharistical
             ,
             and
             such
             all
             ours
             are
             now
             ,
             but
             were
             not
             so
             in
             the
             Days
             of
             the
             Apostles
             .
             And
             the
             use
             of
             Hymns
             neither
             is
             ,
             nor
             can
             be
             denied
             by
             our
             Adversaries
             ,
             as
             well
             in
             the
             
               private
               Synaxes
            
             of
             the
             Apostolical
             Christians
             ,
             as
             in
             the
             Worship
             of
             the
             Temple
             .
             The
             Hymn
             to
             Christ
             as
             a
             God
             in
             Pliny
             ,
             
             appeal'd
             to
             in
             the
             latter
             end
             of
             the
             second
             Century
             as
             a
             very
             early
             evidence
             of
             the
             belief
             of
             his
             Deity
             ,
             seems
             to
             have
             been
             joined
             with
             the
             Eucharist
             .
             
             For
             Pliny
             tells
             us
             ,
             on
             the
             same
             occasion
             ,
             of
             the
             Covenant
             the
             Christians
             entred
             into
             against
             all
             the
             liberties
             us'd
             by
             wicked
             Persons
             .
             And
             the
             publick
             Singers
             are
             mention'd
             in
             the
             earliest
             distinct
             Accounts
             we
             have
             of
             their
             Offices
             ,
             not
             as
             newly
             introduc'd
             ,
             but
             as
             actually
             obtaining
             without
             any
             memory
             of
             a
             late
             Original
             .
             Had
             the
             reasons
             of
             the
             things
             been
             all
             that
             had
             been
             requisite
             for
             raising
             of
             the
             Affections
             ,
             I
             cannot
             conceive
             any
             need
             our
             Adversaries
             can
             pretend
             for
             Singing
             :
             That
             does
             no
             otherways
             contribute
             to
             the
             raising
             of
             the
             Affections
             ,
             than
             as
             the
             assistance
             and
             improvement
             of
             the
             Imagination
             may
             be
             supposed
             to
             contribute
             to
             it
             .
             The
             Singing
             does
             not
             add
             a
             new
             Reason
             ,
             nor
             impose
             the
             old
             ones
             ,
             why
             the
             Affections
             should
             be
             raised
             .
             But
             however
             ,
             they
             do
             dispose
             the
             Affections
             to
             
               follow
               Reason
            
             ,
             more
             readily
             and
             more
             vigorously
             than
             they
             would
             if
             they
             had
             not
             the
             assistance
             of
             a
             favourable
             Imagination
             :
             And
             that
             by
             the
             Nature
             of
             the
             Things
             themselves
             ;
             and
             in
             that
             regard
             ,
             
               Musick
               Instrumental
            
             ,
             also
             was
             acknowledg'd
             to
             have
             the
             same
             influence
             that
             Singing
             had
             by
             the
             Imagination
             over
             the
             Affections
             ;
             and
             to
             add
             to
             the
             advantages
             of
             
               Singing
               Vocally
            
             :
             So
             it
             was
             ,
             that
             
             David's
             playing
             on
             the
             Harp
             cured
             Saul
             of
             the
             
               evil
               Spirit
            
             ,
             by
             curing
             that
             Melancholy
             which
             disposed
             him
             to
             receive
             the
             Influences
             of
             the
             Evil
             Spirit
             :
             So
             it
             was
             ,
             that
             the
             like
             use
             of
             
               Instrumental
               Musick
            
             dispos'd
             Elisha
             for
             the
             influences
             of
             the
             
               good
               Spirit
            
             ,
             by
             composing
             that
             Passion
             which
             his
             Zeal
             against
             the
             Idolatry
             of
             the
             King
             of
             Israel
             had
             put
             the
             Prophet
             into
             ;
             it
             made
             him
             capable
             of
             being
             acted
             by
             the
             Spirit
             of
             Prophesy
             :
             For
             chearfulness
             of
             Temper
             is
             one
             of
             the
             Dispositions
             requir'd
             by
             the
             
               Rabinnical
               Jews
            
             themselves
             ,
             for
             fitting
             Men
             for
             Prophecy
             .
             That
             may
             possibly
             be
             the
             Reason
             why
             the
             Scriptures
             mention
             
               Instrumental
               Musick
            
             as
             receiv'd
             in
             the
             Schools
             of
             the
             Prophets
             ,
             
             especially
             when
             they
             were
             actually
             Prophesying
             ;
             as
             it
             should
             seem
             to
             dispose
             them
             for
             the
             freer
             Influences
             of
             the
             
               Divine
               Spirit
            
             .
             The
             
               Singing
               Hymns
            
             to
             such
             Instruments
             is
             call'd
             Prophesying
             ,
             in
             the
             places
             now
             mention'd
             .
             So
             far
             the
             nature
             of
             the
             Spiritual
             Worship
             of
             the
             Gospel
             ,
             is
             from
             superseding
             this
             assistance
             of
             
               Instrumental
               Musick
            
             ,
             as
             our
             Adversaries
             would
             have
             us
             believe
             ,
             that
             on
             the
             contrary
             
             I
             had
             done
             )
             not
             satisfied
             about
             them
             .
             Onely
             He
             sometimes
             (
             as
             I
             also
             did
             )
             observ'd
             the
             Salient
             water
             to
             describe
             part
             of
             a
             line
             perfectly
             enough
             Parabolical
             ,
             with
             which
             sort
             of
             Curves
             he
             has
             been
             particularly
             conversant
             .
          
           
             This
             made
             me
             resolve
             for
             further
             satisfaction
             to
             attempt
             by
             another
             contrivance
             ,
             (
             of
             whose
             success
             ,
             if
             I
             can
             procure
             the
             Implements
             I
             need
             ,
             Your
             Lordship
             may
             expect
             an
             account
             ,
             )
             what
             the
             Figures
             will
             be
             not
             onely
             of
             Salient
             water
             ,
             but
             Mercury
             ,
             and
             other
             Liquors
             ;
             and
             that
             when
             the
             Receiver
             is
             much
             better
             exhausted
             ,
             then
             it
             was
             necessary
             it
             should
             be
             in
             the
             foregoing
             Experiment
             .
          
        
         
           
             EXPERIMENT
             V.
             
          
           
             About
             a
             way
             of
             speedily
             breaking
             Flat
             Glasses
             ,
             by
             the
             weight
             of
             the
             Atmosphere
             .
          
           
             FOr
             the
             more
             easie
             understanding
             of
             some
             of
             the
             subsequent
             Tryals
             ,
             it
             will
             be
             requisite
             in
             this
             place
             to
             mention
             among
             Experiments
             about
             the
             Spring
             of
             the
             Air
             the
             following
             Phaenomenon
             belonging
             to
             its
             Weight
             .
          
           
             This
             is
             one
             of
             those
             that
             is
             the
             most
             usually
             shown
             to
             Strangers
             ,
             as
             a
             plain
             and
             easie
             proof
             both
             that
             the
             Weight
             of
             the
             incumbent
             Air
             is
             considerable
             ,
             and
             that
             the
             round
             figure
             of
             a
             Receiver
             doth
             much
             more
             conduce
             to
             make
             an
             exhausted
             Glass
             support
             that
             weight
             ,
             than
             if
             the
             upper
             part
             of
             the
             Receiver
             were
             flat
             .
          
           
             To
             make
             this
             Experiment
             we
             provided
             a
             Hoop
             or
             Ring
             of
             Brass
             of
             a
             considerable
             thickness
             ,
             whose
             height
             was
             2
             ½
             ,
             or
             3
             Inches
             ,
             and
             the
             Diameter
             of
             whose
             Cavity
             as
             well
             at
             the
             upper
             as
             lower
             Orifice
             (
             should
             have
             been
             just
             3.
             
             Inches
             ,
             but
             through
             the
             errour
             of
             the
             workman
             )
             was
             3.
             inches
             and
             2
             /
             10.
             
             To
             this
             Hoop
             we
             successively
             fasten'd
             with
             Cement
             divers
             round
             pieces
             of
             Glass
             ,
             such
             as
             is
             used
             by
             Glasiers
             (
             to
             whose
             Shops
             we
             sent
             for
             it
             )
             to
             make
             Panes
             for
             Windows
             ,
             and
             thereby
             made
             the
             Brass-ring
             with
             its
             
             Glass-cover
             a
             kind
             of
             Receiver
             ,
             whose
             open
             Orifice
             we
             carefully
             cemented
             on
             to
             the
             Engine
             ;
             and
             then
             we
             found
             ,
             as
             we
             had
             conjectured
             ,
             that
             usually
             at
             the
             first
             Exuction
             (
             though
             sometimes
             not
             till
             the
             second
             )
             the
             Glass-plate
             would
             be
             broken
             inwards
             with
             such
             violence
             ,
             as
             to
             be
             shatter'd
             into
             a
             great
             multitude
             of
             small
             fragments
             ,
             and
             (
             which
             was
             remarkable
             )
             the
             irruption
             of
             the
             external
             Air
             driving
             the
             Glass
             inwards
             did
             constantly
             make
             a
             loud
             Clap
             ,
             almost
             like
             the
             Report
             of
             a
             Pistol
             .
             Which
             Phaenomenon
             ,
             whether
             it
             may
             help
             us
             to
             discover
             the
             cause
             of
             that
             great
             noise
             ,
             that
             is
             made
             upon
             the
             discharging
             of
             Guns
             ,
             (
             for
             the
             Recoyl
             seems
             to
             depend
             upon
             the
             Dilatation
             and
             Impulse
             of
             the
             Powder
             ,
             )
             I
             must
             not
             stay
             to
             consider
             .
          
        
         
           
             EXPERIMENT
             VI.
             
          
           
             Shewing
             ,
             that
             the
             breaking
             of
             Glass-plates
             in
             the
             foregoing
             Experiment
             ,
             need
             not
             to
             be
             ascrib'd
             to
             the
             Fuga
             Vacui
             .
          
           
             THough
             I
             long
             since
             inform'd
             you
             ,
             that
             in
             the
             Experiments
             I
             then
             presented
             Your
             Lordship
             ,
             it
             was
             not
             my
             purpose
             to
             deliver
             my
             own
             Opinion
             whether
             there
             be
             a
             Vacuum
             ,
             or
             no
             ,
             and
             though
             I
             do
             not
             in
             this
             Tract
             intend
             to
             declare
             my self
             either
             way
             ;
             yet
             ,
             that
             I
             may
             on
             this
             occasion
             also
             show
             ,
             that
             the
             Pressure
             of
             the
             Air
             may
             suffice
             to
             account
             for
             divers
             Phaenomena
             ,
             which
             according
             to
             the
             vulgar
             Philosophers
             must
             be
             referr'd
             to
             Natures
             abhorrency
             of
             a
             Vacuum
             ,
             I
             will
             illustrate
             the
             foregoing
             Experiment
             by
             another
             ,
             the
             substance
             whereof
             is
             this
             .
          
           
             That
             if
             ,
             instead
             of
             the
             above
             mentioned
             brass
             Hoop
             ,
             both
             whose
             Orifices
             are
             of
             equal
             breadth
             ,
             you
             imploy
             a
             hollow
             (
             but
             taller
             )
             piece
             of
             Brass
             ,
             or
             (
             which
             is
             more
             easily
             made
             )
             of
             Latton
             ,
             shap'd
             like
             a
             
               Conus
               iruncatus
            
             ,
             or
             a
             Sugar-loaf
             ,
             whose
             upper
             part
             is
             taken
             off
             parallel
             to
             the
             bottom
             ;
             and
             if
             you
             make
             the
             two
             Orifices
             of
             a
             breadth
             sufficiently
             unequal
             ,
             as
             if
             the
             larger
             being
             made
             
             as
             wide
             as
             that
             of
             our
             Brass-hoop
             ,
             the
             straiter
             were
             less
             than
             an
             Inch
             in
             Diameter
             ;
             You
             will
             find
             ,
             that
             if
             this
             piece
             of
             Metal
             be
             made
             use
             of
             ,
             as
             the
             other
             was
             in
             the
             foregoing
             Experiment
             ,
             the
             flat
             Glass
             cemented
             on
             to
             the
             Orifice
             ,
             will
             be
             easily
             broken
             ,
             as
             formerly
             when
             t
             is
             fastned
             to
             the
             wider
             Orifice
             ;
             but
             if
             the
             straiter
             Orifice
             be
             turn'd
             upward
             ,
             the
             Glass
             that
             covers
             it
             ,
             if
             it
             be
             of
             a
             due
             thickness
             ,
             (
             though
             no
             thicker
             than
             the
             former
             ,
             )
             will
             remain
             entire
             ,
             notwithstanding
             the
             withdrawing
             of
             the
             Air
             from
             beneath
             it
             :
             Which
             seems
             sufficiently
             to
             argue
             ,
             that
             t
             is
             not
             precisely
             Natures
             abhorrency
             of
             a
             vacuum
             ,
             that
             is
             the
             cause
             why
             Glasses
             are
             usually
             broken
             in
             such
             Experiments
             ,
             since
             whether
             the
             wider
             or
             the
             narrower
             Orifice
             be
             uppermost
             ,
             and
             cover'd
             ,
             (
             the
             Metalline
             part
             of
             the
             vessel
             being
             the
             same
             ,
             and
             onely
             varying
             its
             posture
             ,
             )
             the
             capacity
             of
             the
             exhausted
             vessel
             will
             be
             equal
             ;
             and
             therefore
             Nature
             ought
             to
             break
             the
             Glass
             as
             well
             in
             one
             case
             as
             the
             other
             ,
             which
             yet
             the
             Experiment
             shows
             she
             does
             not
             .
          
           
             Wherefore
             this
             Diversity
             seems
             much
             better
             explicable
             by
             saying
             ,
             that
             when
             the
             wider
             Orifice
             is
             uppermost
             ,
             the
             Glass
             that
             covers
             it
             must
             serve
             for
             the
             Basis
             of
             a
             large
             Atmospherical
             Pillar
             ,
             which
             by
             its
             great
             weight
             may
             easily
             force
             the
             resistance
             of
             the
             Glass
             :
             whereas
             when
             the
             smaller
             Orifice
             is
             uppermost
             ,
             there
             leans
             upon
             its
             Cover
             but
             so
             slender
             a
             Pillar
             of
             the
             Atmosphere
             ,
             that
             the
             natural
             tenacity
             or
             mutual
             cohaesion
             of
             parts
             in
             the
             Glass
             is
             not
             to
             be
             surmounted
             by
             a
             weight
             that
             is
             no
             greater
             .
          
        
         
           
             EXPERIMENT
             VII
             .
          
           
             About
             a
             convenient
             way
             of
             breaking
             blown
             Bladders
             by
             the
             Spring
             of
             the
             Air
             included
             in
             them
             :
          
           
             THe
             foregoing
             Experiments
             having
             sufficiently
             manifested
             the
             strength
             of
             the
             Airs
             Spring
             upon
             fluid
             Bodies
             ,
             I
             next
             thought
             fit
             to
             try
             ,
             whether
             the
             force
             of
             a
             little
             included
             Air
             would
             
             also
             upon
             consistent
             and
             even
             Solid
             bodies
             emulate
             the
             Operations
             of
             the
             weight
             of
             the
             Atmosphere
             .
             In
             the
             prosecution
             of
             which
             Enquiry
             we
             thought
             fit
             to
             make
             two
             sorts
             of
             Tryals
             :
             the
             one
             ,
             where
             the
             Air
             is
             included
             in
             the
             Bodies
             ,
             on
             which
             its
             Spring
             does
             work
             ;
             and
             the
             other
             ,
             where
             t
             is
             External
             to
             them
             .
             Of
             the
             first
             sort
             are
             this
             7
             th
             ,
             and
             the
             two
             following
             Experiments
             ;
             and
             of
             the
             second
             sort
             are
             some
             other
             Tryals
             ,
             to
             be
             comprehended
             under
             the
             10
             th
             Experiment
             .
          
           
             Having
             formerly
             mention'd
             to
             Your
             Lordship
             ,
             that
             we
             were
             several
             times
             able
             (
             though
             sometimes
             not
             without
             much
             difficulty
             )
             to
             make
             a
             blown
             Bladder
             break
             with
             the
             Spring
             of
             its
             own
             Air
             ;
             I
             should
             not
             think
             it
             worth
             while
             to
             say
             any
             thing
             here
             about
             the
             same
             Phaenomenon
             ,
             but
             that
             (
             besides
             that
             it
             seems
             odd
             enough
             ,
             and
             is
             not
             unpleasant
             to
             many
             Spectators
             ,
             )
             it
             may
             deserve
             not
             to
             be
             wholly
             neglected
             ,
             because
             a
             Good
             way
             to
             break
             Bladders
             in
             the
             much
             Exhausted
             Receiver
             ,
             may
             sometimes
             prove
             an
             useful
             Expedient
             ,
             especially
             in
             such
             cases
             where
             the
             Experimenter
             (
             who
             sometimes
             either
             is
             not
             skilful
             enough
             ,
             or
             well
             enough
             furnish'd
             with
             accommodations
             to
             regulate
             the
             ingress
             of
             the
             Air
             )
             would
             very
             suddainly
             supply
             the
             Receiver
             with
             fresh
             Air
             ,
             when
             it
             has
             been
             much
             emptied
             ,
             without
             danger
             of
             letting
             in
             too
             much
             Air
             from
             without
             .
             Not
             to
             mention
             ,
             that
             the
             Air
             ,
             included
             in
             the
             Bladder
             to
             be
             broken
             ,
             may
             be
             so
             mingled
             with
             streams
             ,
             or
             imbu'd
             with
             divers
             qualities
             ,
             as
             to
             be
             much
             fitter
             than
             common
             Air
             for
             some
             particular
             Purposes
             .
          
           
             We
             shall
             then
             for
             the
             affinities
             sake
             between
             this
             Tryal
             and
             the
             former
             ,
             subjoyn
             now
             the
             way
             ,
             by
             which
             we
             seldom
             fail'd
             of
             breaking
             Bladders
             in
             our
             emptied
             Receivers
             .
             For
             this
             purpose
             ,
             the
             blown
             Bladder
             that
             was
             to
             be
             burst
             ,
             having
             the
             neck
             very
             closely
             and
             strongly
             tyed
             ,
             was
             kept
             a
             pretty
             while
             in
             the
             Receiver
             ,
             whilst
             the
             Air
             was
             pumping
             out
             ,
             and
             then
             taken
             out
             again
             ,
             that
             ,
             now
             the
             fibres
             were
             stretcht
             and
             relax'd
             ,
             the
             Capacity
             being
             lessen'd
             by
             a
             new
             ligature
             that
             I
             order'd
             to
             be
             strongly
             made
             near
             the
             Neck
             ,
             the
             Bladder
             might
             be
             lessen'd
             though
             the
             Air
             were
             but
             
             the
             same
             ,
             and
             the
             Membrance
             being
             not
             so
             capable
             of
             yielding
             as
             before
             ,
             upon
             the
             second
             exhaustion
             of
             the
             Receiver
             the
             Bladder
             in
             it
             would
             break
             ,
             far
             more
             easily
             then
             otherwise
             ,
             and
             perhaps
             be
             oddly
             enough
             lacerated
             .
          
           
             We
             sometimes
             also
             varied
             this
             way
             of
             disposing
             Bladders
             to
             be
             burst
             ,
             by
             omitting
             the
             preparatory
             putting
             in
             of
             the
             Bladder
             into
             the
             Receiver
             ,
             and
             onely
             taking
             it
             in
             a
             little
             near
             the
             Neck
             ,
             that
             ,
             the
             Bladder
             having
             not
             been
             blown
             very
             full
             at
             first
             ,
             the
             tension
             of
             the
             included
             Air
             might
             be
             greater
             .
             But
             this
             last
             way
             is
             to
             be
             made
             use
             of
             ,
             when
             the
             thing
             we
             desire
             is
             ,
             that
             the
             Bladder
             by
             breaking
             at
             a
             certain
             time
             may
             part
             with
             its
             Air
             ,
             and
             not
             when
             t
             is
             onely
             to
             give
             an
             instance
             of
             the
             force
             of
             the
             Spring
             of
             uncompress'd
             Air
             against
             the
             sides
             of
             the
             Vessel
             that
             contain
             it
             .
          
        
         
           
             EXPERIMENT
             VIII
             .
          
           
             About
             the
             lifting
             up
             a
             considerable
             Weight
             by
             the
             bare
             Spring
             of
             a
             little
             Air
             included
             in
             a
             Bladder
             .
          
           
             YOu
             will
             easily
             believe
             ,
             that
             the
             Force
             imploy'd
             (
             in
             the
             foregoing
             Experiment
             )
             by
             the
             Air
             ,
             to
             break
             the
             well
             blown
             Bladders
             t
             is
             included
             in
             ,
             is
             considerable
             ,
             if
             I
             here
             adde
             ,
             that
             a
             small
             quantity
             of
             Air
             ,
             which
             will
             not
             fill
             ¼
             of
             a
             Bladder
             ,
             will
             not
             onely
             serve
             to
             blow
             it
             quite
             up
             ,
             but
             will
             manifestly
             swell
             it
             ,
             though
             that
             Effect
             be
             oppos'd
             not
             onely
             by
             the
             resistance
             of
             the
             Bladder
             it self
             ,
             but
             by
             a
             considerable
             weight
             tied
             to
             the
             bottom
             of
             it
             ,
             as
             in
             the
             following
             Experiment
             .
          
           
             We
             took
             a
             middle
             siz'd
             Bladder
             (
             of
             a
             Hog
             or
             Sheep
             ,
             )
             and
             having
             press'd
             out
             the
             Air
             ,
             till
             there
             remain'd
             but
             about
             a
             fourth
             or
             fifth
             part
             (
             by
             guess
             ,
             )
             we
             caus'd
             the
             Neck
             to
             be
             very
             strongly
             tyed
             up
             again
             :
             also
             round
             about
             the
             opposite
             part
             of
             the
             Bladder
             ,
             within
             about
             an
             inch
             of
             the
             bottom
             ,
             we
             so
             strongly
             tyed
             another
             String
             ,
             that
             it
             would
             not
             be
             made
             to
             slip
             off
             by
             a
             not
             inconsiderable
             
             weight
             we
             hung
             at
             it
             .
             Then
             fastning
             the
             Neck
             of
             the
             Bladder
             to
             the
             turning
             Key
             ,
             we
             convey'd
             the
             Bladder
             and
             the
             Weight
             hanging
             at
             it
             into
             a
             large
             Receiver
             ,
             in
             which
             when
             it
             began
             to
             be
             pretty
             well
             exhausted
             ,
             the
             Air
             within
             the
             Bladder
             being
             freed
             from
             the
             wonted
             Pressure
             of
             the
             Air
             without
             it
             ,
             did
             by
             its
             own
             Spring
             manifestly
             swell
             ,
             and
             thereby
             notably
             shorten
             the
             Bladder
             that
             contain'd
             it
             ,
             and
             by
             consequence
             visibly
             lifted
             up
             the
             Weight
             ,
             (
             that
             resisted
             that
             change
             of
             figure
             ,
             )
             which
             exceeded
             15
             pound
             of
             16.
             ounces
             to
             the
             Pound
             .
          
           
             After
             that
             we
             took
             a
             larger
             Bladder
             ,
             and
             having
             let
             out
             so
             much
             Air
             ,
             that
             it
             was
             left
             lank
             enough
             ,
             we
             fasten'd
             the
             two
             ends
             of
             it
             to
             the
             upper
             part
             of
             the
             Receiver
             ,
             (
             for
             which
             else
             it
             would
             have
             been
             too
             long
             ,
             )
             and
             tyed
             a
             Weight
             (
             but
             not
             the
             same
             )
             so
             as
             that
             it
             hung
             down
             from
             the
             middle
             of
             the
             Bladder
             ;
             then
             exhausting
             the
             Receiver
             as
             before
             ,
             though
             the
             Bladder
             ,
             and
             this
             new
             Weight
             which
             stretcht
             it
             ,
             reach'd
             so
             low
             ,
             as
             that
             for
             a
             while
             we
             could
             scarce
             see
             whether
             it
             hung
             in
             the
             Air
             or
             no
             ,
             yet
             at
             length
             we
             perceiv'd
             the
             Bladder
             to
             swell
             ,
             and
             concluded
             that
             it
             had
             lifted
             up
             its
             Clog
             about
             an
             Inch
             ;
             which
             was
             confirm'd
             by
             the
             return
             we
             permitted
             of
             the
             Air
             into
             the
             Receiver
             ,
             upon
             which
             the
             Bladder
             became
             more
             wrinkled
             than
             before
             ,
             and
             the
             Weight
             descended
             ,
             which
             being
             taken
             off
             ,
             and
             weighed
             in
             a
             Statera
             ,
             amounted
             to
             abovt
             28
             Pounds
             .
             We
             would
             have
             reiterated
             the
             Experiment
             ,
             but
             so
             heavy
             a
             Weight
             having
             broken
             the
             Bladder
             ,
             we
             were
             discouraged
             from
             proceeding
             any
             farther
             ,
             especially
             in
             regard
             of
             the
             difficulty
             of
             bringing
             by
             this
             contrivance
             the
             strength
             of
             the
             Airs
             Spring
             to
             any
             exact
             computation
             ,
             though
             it
             sufficiently
             shews
             what
             I
             design'd
             it
             should
             ,
             namely
             that
             the
             Spring
             of
             a
             little
             included
             Air
             may
             be
             able
             even
             in
             so
             slight
             a
             contrivance
             to
             raise
             a
             great
             Weight
             .
          
           
             Whether
             this
             Experiment
             may
             any
             way
             illustrate
             the
             motion
             of
             Muscles
             ,
             made
             by
             Inflation
             ,
             Contraction
             ,
             &c.
             it
             belongs
             not
             to
             this
             place
             to
             consider
             .
          
        
         
           
           
             EXPERIMENT
             IX
             .
          
           
             About
             the
             breaking
             of
             Hermetically
             seal'd
             Bubbles
             of
             Glass
             by
             the
             bare
             Spring
             of
             their
             own
             Air.
             
          
           
             I
             Shall
             premise
             to
             the
             following
             Tryals
             an
             Experiment
             ,
             wherein
             Uncompress'd
             Air
             is
             made
             by
             its
             own
             bare
             Spring
             to
             break
             the
             solid
             body
             it self
             t
             is
             shut
             up
             in
             .
             And
             this
             I
             the
             rather
             set
             down
             before
             the
             subsequent
             Tryals
             ,
             
             because
             in
             our
             already
             publish'd
             
               Physico-Mechanical
               Experiments
            
             mention
             has
             been
             made
             of
             this
             Tryal
             ,
             as
             of
             one
             that
             we
             could
             not
             then
             make
             to
             succeed
             ;
             we
             have
             since
             ,
             imploying
             smaller
             Receivers
             ,
             made
             it
             often
             enough
             prosperously
             ,
             somewhat
             to
             the
             wonder
             of
             eminent
             Virtuosi
             ,
             who
             confess'd
             to
             me
             they
             had
             made
             frequent
             and
             divers
             attempts
             to
             perform
             the
             same
             thing
             ,
             without
             ever
             succeeding
             in
             any
             of
             them
             .
          
           
             But
             it
             will
             not
             be
             requisite
             to
             multiply
             relations
             about
             this
             Particular
             ,
             and
             therefore
             I
             shall
             set
             down
             but
             this
             one
             ,
             which
             I
             meet
             with
             among
             my
             loose
             Notes
             .
          
           
             A
             large
             Glass
             Bubble
             Hermetically
             seal'd
             being
             put
             into
             the
             Receiver
             ,
             and
             the
             Air
             drawn
             out
             as
             much
             as
             in
             usual
             Operations
             ,
             and
             somewhat
             more
             ,
             though
             I
             told
             the
             Company
             before
             hand
             that
             I
             had
             several
             times
             observ'd
             ,
             that
             such
             Bubbles
             would
             not
             break
             immediately
             ,
             but
             somewhile
             after
             the
             withdrawing
             the
             Air
             from
             about
             them
             ,
             yet
             this
             continued
             so
             long
             entire
             after
             we
             had
             left
             off
             Pumping
             ,
             that
             presuming
             it
             had
             been
             blown
             too
             strong
             ,
             I
             began
             to
             dispair
             of
             the
             Experiments
             succeeding
             ;
             when
             ,
             whilst
             we
             were
             providing
             something
             else
             to
             put
             into
             the
             Receiver
             ,
             and
             as
             I
             guess'd
             4.
             minuts
             after
             the
             Pump
             had
             been
             let
             alone
             ,
             the
             Bubble
             surpriz'd
             us
             with
             its
             being
             broken
             with
             such
             violence
             by
             the
             Spring
             of
             the
             included
             Air
             ,
             that
             the
             fragments
             of
             it
             were
             dash'd
             every
             way
             against
             the
             sides
             of
             the
             Receiver
             ,
             and
             broken
             so
             very
             small
             ,
             that
             when
             we
             came
             to
             take
             it
             up
             ,
             the
             Powder
             was
             by
             the
             By-standers
             compar'd
             to
             the
             small
             Sand
             wont
             to
             be
             imploy'd
             to
             
             dry
             Papers
             ,
             that
             have
             been
             newly
             writ
             upon
             with
             Inck.
             The
             Reason
             why
             the
             Bubble
             broke
             so
             slowly
             I
             cannot
             now
             stay
             to
             propose
             ,
             no
             more
             then
             to
             examine
             whether
             the
             difficulty
             of
             breaking
             vessels
             of
             Glass
             ,
             no
             thicker
             then
             these
             Bubbles
             ,
             proceed
             from
             some
             weakning
             of
             the
             Spring
             of
             imprisoned
             Air
             ,
             by
             its
             stretching
             a
             little
             the
             including
             Glass
             ,
             (
             for
             in
             another
             case
             we
             have
             observ'd
             this
             Glass
             to
             be
             stretchable
             by
             the
             pressure
             of
             Air
             ;
             )
             or
             from
             hence
             ,
             that
             't
             was
             very
             hard
             ,
             as
             I
             have
             elsewhere
             mention'd
             ,
             to
             avoid
             rarifying
             the
             Air
             a
             little
             ,
             and
             consequently
             weakning
             its
             Spring
             ,
             by
             the
             heat
             that
             was
             necessary
             to
             be
             imploy'd
             about
             the
             sealing
             up
             the
             Bubble
             .
          
        
         
           
             EXPERIMENT
             X.
             
          
           
             Containing
             two
             or
             three
             Tryals
             of
             the
             force
             of
             the
             Spring
             of
             our
             Air
             uncompress'd
             upon
             stable
             and
             even
             solid
             Bodies
             ,
             (
             whereto
             t
             is
             external
             .
             )
          
           
             IN
             prosecution
             of
             the
             Enquiry
             propos'd
             in
             the
             Title
             ,
             we
             made
             (
             among
             others
             )
             the
             following
             Tryals
             .
          
           
             
               The
               I.
               TRYAL
               .
            
             
               1.
               
               WE
               took
               the
               Brass-hoop
               ,
               mention'd
               in
               the
               5
               th
               Experiment
               ,
               (
               whose
               Diameter
               is
               somewhat
               above
               3.
               
               Inches
               ,
               )
               and
               having
               caus'd
               a
               Glazier
               to
               cut
               some
               Plates
               of
               Glass
               ,
               such
               as
               are
               used
               for
               making
               the
               Quarrels
               of
               Windows
               ,
               till
               he
               had
               brought
               them
               to
               a
               Size
               ,
               &
               a
               roundness
               fit
               to
               serve
               for
               Covers
               to
               that
               brass-hoop
               ,
               we
               carefully
               fasten'd
               one
               of
               them
               with
               Cement
               to
               the
               upper
               Orifice
               of
               the
               Hoop
               or
               Ring
               ,
               and
               then
               cementing
               the
               lower
               Orifice
               to
               the
               Engine
               ,
               so
               that
               the
               Vessel
               ,
               compos'd
               of
               the
               Metal
               and
               Glass
               ,
               serv'd
               for
               a
               small
               Receiver
               ;
               we
               whelm'd
               over
               it
               a
               large
               and
               strong
               Receiver
               ,
               which
               we
               also
               fasten'd
               on
               to
               the
               Engine
               with
               Cement
               after
               the
               usual
               manner
               .
               By
               which
               Contrivance
               it
               was
               necessary
               ,
               that
               when
               the
               Pump
               was
               set
               on
               work
               ,
               the
               included
               Receiver
               (
               of
               Brass
               and
               Glass
               )
               should
               have
               its
               Air
               withdrawn
               ,
               and
               yet
               the
               Air
               in
               the
               larger
               Receiver
               should
               not
               be
               
               pump'd
               out
               but
               by
               breaking
               through
               the
               Glass
               ,
               so
               that
               the
               internal
               Air
               of
               the
               Metalline
               Receiver
               (
               as
               we
               may
               call
               it
               for
               distinctions
               sake
               )
               being
               pump'd
               out
               ,
               the
               Glass
               Plate
               ,
               that
               made
               part
               of
               that
               Receiver
               ,
               must
               lye
               expos'd
               to
               the
               pressure
               of
               the
               Ambient
               Air
               shut
               up
               in
               the
               other
               Receiver
               ,
               without
               having
               the
               former
               assistance
               of
               the
               now
               withdrawn
               Air
               to
               resist
               the
               Pressure
               ;
               wherefore
               ,
               as
               we
               expected
               ,
               at
               the
               first
               or
               second
               Exuction
               of
               the
               Air
               ,
               included
               in
               the
               small
               metalline
               Receiver
               ,
               the
               Glass-plate
               was
               ,
               by
               the
               Pressure
               of
               the
               incumbent
               Air
               ,
               contain'd
               in
               the
               great
               Receiver
               ,
               broken
               into
               an
               100
               pieces
               ,
               which
               were
               beaten
               inwards
               into
               the
               Cavity
               of
               the
               Hoop
               .
            
          
           
             
               The
               II.
               Tryal
               .
            
             
               2.
               
               This
               done
               ,
               to
               shew
               that
               there
               needed
               not
               the
               Spring
               of
               so
               great
               a
               quantity
               of
               included
               Air
               to
               break
               such
               Glasses
               ,
               we
               took
               another
               Roundish
               one
               ,
               which
               ,
               though
               wide
               enough
               at
               the
               Orifice
               to
               cover
               the
               Brass
               Ring
               &
               the
               new
               Glass-plate
               that
               we
               had
               cemented
               on
               it
               ,
               was
               yet
               so
               low
               ,
               that
               we
               estimated
               it
               to
               hold
               but
               a
               6
               th
               part
               of
               what
               the
               large
               Receiver
               ,
               formerly
               imploy'd
               ,
               is
               able
               to
               contain
               ;
               and
               having
               whelm'd
               this
               smaller
               vessel
               ,
               which
               was
               shap'd
               like
               those
               Cups
               they
               call
               Tumblers
               ,
               over
               the
               Metalline
               Receiver
               ,
               and
               well
               fasten'd
               it
               to
               the
               Engine
               with
               Cement
               ,
               we
               found
               that
               though
               this
               External
               Receiver
               had
               a
               great
               part
               of
               its
               Cavity
               fill'd
               by
               the
               included
               one
               ,
               yet
               when
               this
               Internal
               one
               was
               exhausted
               by
               an
               Exuction
               or
               two
               ,
               the
               Spring
               of
               the
               little
               Air
               that
               remain'd
               ,
               was
               able
               to
               break
               the
               Plate
               into
               a
               multitude
               of
               fragments
               .
            
          
           
             
               The
               III.
               Tryal
               .
            
             
               3.
               
               Because
               the
               Glass-Plates
               hitherto
               mention'd
               seem'd
               not
               so
               thick
               ,
               but
               that
               the
               Pressure
               of
               the
               included
               Air
               might
               be
               able
               to
               give
               considerabler
               Instances
               of
               its
               Force
               ;
               in
               stead
               of
               the
               Metalline
               Receivers
               hitherto
               employed
               ,
               we
               took
               a
               square
               Bottle
               of
               Glass
               ,
               which
               we
               judg'd
               to
               be
               able
               to
               contain
               about
               a
               Pint
               (
               or
               Pound
               )
               of
               Water
               ,
               and
               which
               had
               been
               provided
               to
               keep
               subtle
               Chymical
               Liquors
               in
               ,
               for
               which
               use
               we
               are
               not
               wont
               to
               choose
               weak
               ones
               .
               
               This
               we
               inverted
               ,
               and
               apply'd
               to
               the
               Engine
               as
               a
               Receiver
               ,
               over
               which
               we
               whelm'd
               the
               large
               Receiver
               formerly
               mention'd
               ;
               and
               having
               cemented
               it
               on
               ,
               as
               in
               the
               foregoing
               Experiments
               ,
               we
               set
               the
               Pump
               on
               work
               to
               empty
               the
               internal
               Receiver
               ,
               (
               or
               square
               Bottle
               ,
               )
               by
               which
               means
               the
               withdrawing
               of
               the
               Air
               ,
               and
               the
               figure
               of
               the
               vessel
               (
               which
               was
               inconvenient
               for
               resisting
               )
               suffer'd
               the
               Pressure
               of
               the
               Air
               included
               in
               the
               external
               Receiver
               to
               crush
               the
               viol
               into
               a
               great
               number
               of
               pieces
               .
            
             
               And
               to
               vary
               this
               Experiment
               ,
               as
               we
               did
               that
               of
               breaking
               the
               metalline
               Receivers
               ,
               we
               took
               another
               Glass
               of
               the
               shape
               and
               about
               the
               bigness
               of
               the
               former
               ,
               and
               having
               apply'd
               it
               to
               the
               Engine
               as
               before
               ,
               and
               cover'd
               it
               with
               a
               Receiver
               that
               was
               little
               higher
               than
               it self
               ,
               we
               found
               ,
               that
               upon
               the
               exhaustion
               of
               the
               Air
               the
               second
               square
               Glass
               was
               likewise
               broken
               into
               many
               fragments
               ,
               some
               of
               which
               were
               of
               so
               great
               a
               thickness
               ,
               as
               mov'd
               some
               wonder
               ,
               that
               the
               bare
               Pressure
               of
               the
               Air
               was
               able
               to
               break
               such
               a
               vessel
               ,
               though
               probably
               the
               Cracks
               ,
               that
               reacht
               to
               them
               ,
               were
               begun
               in
               much
               weaker
               parts
               of
               the
               Glass
               .
            
             
               NB.
               1.
               
               The
               bottoms
               and
               the
               necks
               of
               both
               these
               square
               Bottles
               were
               entire
               enough
               ;
               by
               which
               it
               seem'd
               probable
               ,
               that
               the
               vessels
               had
               been
               broken
               by
               the
               Pressure
               of
               the
               Air
               against
               the
               Sides
               ,
               which
               were
               not
               onely
               thinner
               than
               the
               parts
               above
               named
               ,
               but
               expos'd
               a
               larger
               Superficies
               to
               the
               lateral
               Pressure
               of
               the
               Air
               ,
               than
               to
               the
               perpendicular
               .
            
             
               2.
               
               We
               observ'd
               in
               one
               of
               the
               two
               last
               Experiments
               ,
               that
               the
               Vessel
               did
               not
               break
               presently
               upon
               the
               last
               Exuction
               that
               was
               made
               of
               the
               included
               Air
               ,
               but
               a
               considerable
               time
               after
               ,
               which
               it
               seems
               was
               requisite
               to
               allow
               the
               comprest
               parts
               of
               the
               Glass
               time
               to
               change
               their
               places
               ;
               and
               this
               Phaenomenon
               I
               therefore
               mention
               ,
               because
               the
               same
               thing
               that
               here
               happen'd
               in
               the
               breaking
               a
               Glass
               inwards
               by
               the
               Spring
               of
               the
               Air
               ,
               I
               elsewhere
               observ'd
               to
               have
               happen'd
               in
               breaking
               a
               Glass
               outwards
               by
               the
               same
               Spring
               .
            
             
               3.
               
               To
               confirm
               ,
               that
               it
               is
               the
               Spring
               of
               the
               External
               Receivers
               Air
               that
               is
               the
               Agent
               in
               those
               Fractures
               of
               Glasses
               ,
               and
               to
               prevent
               
               or
               remove
               some
               scruples
               ,
               we
               thought
               fit
               to
               make
               this
               variation
               in
               the
               Experiment
               .
               We
               applyed
               a
               Plate
               of
               Glass
               ,
               just
               like
               those
               formerly
               mentioned
               ,
               to
               the
               Brass-hoop
               ;
               but
               in
               the
               cementing
               of
               it
               on
               ,
               we
               plac'd
               in
               the
               thickness
               of
               the
               Cement
               a
               small
               Pipe
               of
               Glass
               of
               about
               an
               Inch
               long
               ,
               whose
               Cavity
               was
               not
               so
               big
               as
               that
               of
               a
               Straw
               ,
               and
               which
               being
               left
               open
               at
               both
               the
               ends
               might
               serve
               for
               a
               little
               Channel
               ,
               through
               which
               the
               Air
               might
               pass
               from
               the
               External
               Receiver
               to
               the
               Internal
               ;
               over
               This
               we
               whelm'd
               one
               of
               the
               small
               Receivers
               above
               mentioned
               ,
               &
               then
               ,
               though
               we
               set
               the
               Pump
               on
               work
               much
               longer
               then
               would
               have
               needed
               if
               this
               litle
               Pipe
               had
               not
               been
               made
               use
               of
               ,
               we
               found
               ,
               as
               we
               expected
               ,
               that
               the
               Internal
               Receiver
               continued
               entire
               ,
               because
               the
               Air
               ,
               whose
               Spring
               should
               have
               broken
               it
               ,
               having
               liberty
               to
               pass
               through
               the
               Pipe
               ,
               and
               consequently
               to
               expand
               it self
               into
               the
               place
               deserted
               by
               the
               Air
               pump'd
               out
               ,
               did
               by
               that
               Expansion
               weaken
               its
               Spring
               too
               much
               ,
               to
               retain
               strength
               enough
               to
               break
               the
               Metalline
               (
               or
               Internal
               )
               Receiver
               .
            
             
               But
               here
               t
               is
               to
               be
               noted
               ,
               that
               either
               the
               Pipe
               must
               be
               made
               bigger
               than
               that
               lately
               mentioned
               ,
               or
               the
               Exuction
               of
               the
               Air
               must
               not
               be
               made
               by
               the
               Pump
               as
               nimbly
               as
               we
               can
               ,
               or
               otherwise
               the
               Plate
               of
               Glass
               may
               be
               broken
               notwithstanding
               the
               Pipe
               ;
               because
               the
               Air
               contain'd
               in
               the
               External
               Receiver
               ,
               having
               a
               force
               much
               greater
               than
               is
               necessary
               to
               break
               such
               a
               Plate
               ,
               it
               may
               well
               happen
               (
               as
               I
               have
               sometimes
               found
               it
               do
               )
               that
               if
               the
               Air
               be
               hastily
               drawn
               out
               of
               the
               Internal
               Receiver
               ,
               that
               Air
               ,
               which
               should
               succeed
               in
               its
               room
               ,
               cannot
               get
               fast
               enough
               out
               of
               that
               external
               Receiver
               through
               so
               small
               a
               Pipe
               ,
               and
               the
               Air
               remaining
               in
               that
               external
               Receiver
               will
               yet
               retain
               a
               Spring
               strong
               enough
               to
               break
               the
               Glass
               .
               To
               illustrate
               which
               ,
               I
               shall
               propose
               this
               Experiment
               ,
               That
               sometimes
               ,
               when
               I
               have
               at
               the
               flame
               of
               a
               Lamp
               caus'd
               Glass
               Bubbles
               to
               be
               blown
               with
               exceeding
               slender
               Stems
               ,
               if
               they
               were
               nimbly
               remov'd
               out
               of
               the
               flame
               whilst
               they
               were
               ignited
               ,
               they
               would
               according
               to
               my
               conjecture
               be
               either
               broken
               ,
               if
               they
               cool'd
               too
               fast
               ;
               or
               compress'd
               inward
               ,
               if
               they
               long
               enough
               retain'd
               the
               
               Softness
               they
               had
               given
               them
               by
               Fusion
               .
               For
               the
               Air
               in
               the
               Bubble
               being
               exceedingly
               rarified
               and
               expanded
               ,
               whilst
               the
               Glass
               is
               kept
               in
               the
               flame
               ,
               and
               coming
               to
               cool
               hastily
               when
               remov'd
               from
               thence
               ,
               looses
               upon
               refrigeration
               the
               Spring
               the
               heat
               had
               given
               it
               ,
               and
               so
               ,
               if
               the
               External
               Air
               cannot
               press
               in
               fast
               enough
               through
               the
               too
               slender
               Pipe
               ,
               there
               will
               not
               get
               in
               Air
               enough
               to
               resist
               the
               Pressure
               of
               the
               Atmosphere
               ,
               and
               therefore
               if
               this
               Pressure
               find
               the
               Bubble
               yet
               soft
               ,
               it
               will
               press
               it
               a
               little
               inwards
               ,
               and
               either
               flatten
               it
               ,
               or
               make
               a
               dimple
               in
               it
               ,
               though
               the
               Orifice
               of
               the
               Pipe
               be
               left
               open
               .
            
          
        
         
           
             EXPERIMENT
             XI
             .
          
           
             Shewing
             ,
             that
             Mercury
             will
             in
             Tubes
             be
             raised
             by
             Suction
             no
             higher
             then
             the
             weight
             of
             the
             Atmosphere
             is
             able
             to
             impell
             it
             up
             .
          
           
             T
             Is
             sufficiently
             known
             ,
             that
             the
             common
             opinion
             of
             Philosophers
             ,
             and
             especially
             of
             those
             which
             follovv
             Aristotle
             ,
             has
             long
             been
             ,
             and
             still
             is
             ,
             that
             the
             cause
             of
             the
             Ascension
             of
             Water
             upon
             Suction
             ,
             and
             particularly
             in
             those
             Pumps
             ,
             where
             the
             Water
             seems
             of
             its
             own
             accord
             to
             follow
             the
             rising
             Sucker
             ,
             is
             Natures
             abhorrency
             of
             a
             Vacuum
             .
             Against
             this
             receiv'd
             Opinion
             divers
             of
             the
             Modern
             Philosophers
             have
             oppos'd
             themselves
             .
             But
             as
             some
             of
             them
             were
             Vacuists
             ,
             and
             others
             Plenists
             ,
             they
             have
             explicated
             the
             Ascension
             of
             Water
             in
             Sucking-pumps
             upon
             very
             different
             grounds
             ;
             so
             that
             many
             Ingenious
             men
             continue
             yet
             irresolv'd
             in
             this
             noble
             Controversie
             .
             Wherefore
             though
             I
             have
             formerly
             made
             ,
             and
             now
             renew
             a
             solemn
             Profession
             ,
             that
             I
             do
             not
             in
             this
             Treatise
             intend
             to
             declare
             either
             for
             or
             against
             the
             being
             of
             a
             Vacuum
             ;
             and
             though
             I
             have
             *
             elsewhere
             occasionally
             acknowledg'd
             my Self
             not
             to
             acquiesce
             fully
             in
             what
             either
             the
             ancient
             or
             the
             modern
             Philosophers
             have
             taught
             about
             the
             adequate
             cause
             of
             Suction
             ;
             (
             in
             the
             
             assigning
             of
             which
             ,
             I
             think
             ,
             I
             have
             shown
             them
             to
             have
             been
             somewhat
             deficient
             ,
             )
             yet
             since
             I
             think
             some
             Experiments
             ,
             of
             importance
             to
             this
             Controversie
             ,
             may
             be
             better
             made
             by
             the
             help
             of
             our
             Engine
             ,
             than
             they
             have
             been
             by
             any
             Instrument
             I
             have
             yet
             heard
             of
             ,
             I
             shall
             now
             adde
             the
             Tryals
             I
             made
             ,
             to
             shew
             both
             that
             whether
             there
             be
             or
             may
             be
             a
             Vacuum
             or
             not
             ,
             there
             is
             no
             need
             to
             have
             recourse
             to
             a
             
               fuga
               vacui
            
             to
             explicate
             Suction
             ;
             and
             also
             that
             whatever
             other
             Causes
             have
             by
             Gassendus
             and
             Cartesius
             been
             ingeniously
             propos'd
             to
             explicate
             Suction
             ,
             it
             seems
             to
             depend
             clearly
             upon
             the
             Weight
             of
             the
             Atmosphere
             ,
             or
             in
             some
             cases
             upon
             the
             Spring
             of
             the
             Air
             ;
             though
             I
             deny
             not
             ,
             that
             other
             Causes
             may
             contribute
             to
             that
             Pressure
             of
             the
             Air
             ,
             which
             I
             take
             to
             be
             the
             grand
             and
             immediate
             Agent
             in
             these
             Phaenomena
             .
          
           
             We
             took
             a
             Brass-Pipe
             bended
             like
             a
             Siphon
             ,
             and
             fitted
             at
             the
             bigger
             end
             with
             a
             Stop-cock
             &c
             ,
             
             as
             is
             delineated
             in
             the
             Figure
             ,
             (
             which
             Instrument
             for
             brevities
             sake
             I
             often
             call
             an
             Exhausting
             (
             or
             Sucking
             )
             Siphon
             ,
             )
             and
             to
             the
             slender
             end
             of
             this
             we
             fastned
             with
             good
             Cement
             the
             upper
             end
             of
             a
             Cylindrical
             Pipe
             of
             Glass
             ,
             of
             about
             fifty
             inches
             long
             ,
             and
             open
             at
             both
             ends
             ,
             and
             having
             the
             lower
             end
             open
             into
             a
             Glass
             of
             stagnant
             Quick-silver
             ,
             whose
             upper
             Superficies
             reacht
             a
             pretty
             deal
             higher
             than
             the
             immerst
             Orifice
             of
             the
             Glass
             Cane
             .
             These
             things
             being
             thus
             prepared
             ,
             we
             caus'd
             the
             Pump
             to
             be
             set
             on
             work
             ,
             whereby
             the
             Air
             being
             by
             degrees
             drawn
             out
             of
             the
             Exhausting
             Siphon
             ,
             and
             consequently
             of
             the
             Glass-Cane
             that
             open'd
             into
             it
             ;
             the
             stagnant
             Mercury
             was
             proportionably
             impell'd
             up
             into
             the
             Glass-pipe
             ,
             till
             it
             had
             attain'd
             to
             its
             due
             height
             ,
             which
             exceeded
             not
             30.
             inches
             .
             And
             then
             ,
             though
             there
             remain'd
             in
             the
             upper
             part
             of
             the
             Pipe
             above
             20
             inches
             unfill'd
             with
             Quick-silver
             ,
             yet
             we
             could
             not
             by
             further
             pumping
             raise
             that
             fluid
             Metal
             any
             higher
             .
          
           
             By
             which
             it
             seems
             manifest
             enough
             ,
             that
             whatever
             many
             Learned
             men
             have
             taught
             ,
             or
             others
             do
             yet
             believe
             about
             the
             unlimited
             power
             that
             Nature
             would
             exercise
             ,
             to
             prevent
             what
             they
             call
             
             a
             Vacuum
             ;
             yet
             this
             power
             has
             its
             bounds
             ,
             and
             those
             depend
             not
             so
             much
             upon
             the
             Exigency
             of
             that
             Principle
             ,
             which
             the
             School-men
             call
             a
             
               fuga
               vacui
            
             ,
             as
             upon
             the
             specifick
             Gravity
             of
             the
             Liquor
             to
             be
             rais'd
             by
             Suction
             .
             For
             confirmation
             of
             which
             ,
             we
             substituted
             in
             stead
             of
             the
             stagnant
             Mercury
             a
             bason
             of
             Water
             ,
             and
             though
             instead
             of
             the
             many
             Sucks
             we
             had
             fruitlesly
             imploy'd
             to
             raise
             the
             Quick-silver
             above
             the
             lately
             mentioned
             height
             ,
             we
             now
             imploy'd
             but
             one
             Exsuction
             ,
             (
             or
             less
             then
             a
             full
             one
             ,
             )
             which
             did
             but
             in
             part
             empty
             the
             Exhausting
             Siphon
             :
             yet
             the
             Water
             upon
             the
             opening
             of
             the
             Stop-cock
             was
             not
             onely
             impell'd
             to
             the
             very
             top
             of
             the
             Glass-Cane
             ,
             but
             likewise
             continued
             running
             for
             a
             good
             while
             through
             the
             Exhausting
             Siphon
             ,
             and
             thence
             fell
             upon
             the
             plate
             of
             the
             Engine
             ;
             so
             that
             it
             seem'd
             an
             odd
             spectacle
             to
             those
             that
             knew
             not
             the
             reason
             of
             it
             ,
             to
             see
             the
             Water
             running
             very
             briskly
             of
             its
             own
             accord
             as
             they
             imagined
             out
             of
             the
             shorter
             leg
             of
             a
             Siphon
             ;
             especially
             that
             leg
             being
             perhaps
             not
             above
             a
             a
             quarter
             so
             long
             as
             the
             other
             .
             And
             here
             I
             must
             not
             omit
             this
             considerable
             circumstance
             ,
             that
             though
             sometimes
             in
             the
             Torricellian
             Experiment
             I
             have
             observ'd
             the
             Mercury
             to
             stand
             at
             thirty
             inches
             ,
             and
             now
             and
             then
             above
             it
             ,
             yet
             the
             height
             of
             the
             Mercury
             elevated
             in
             our
             Glass-Cane
             appear'd
             not
             ,
             when
             measured
             ,
             to
             reach
             fully
             29.
             inches
             and
             a
             quarter
             ,
             which
             I
             thought
             it
             was
             not
             difficult
             to
             render
             a
             reason
             of
             ,
             from
             the
             varying
             weight
             of
             the
             Atmosphere
             ;
             and
             accordingly
             consulting
             the
             Baroscope
             ,
             (
             that
             stood
             in
             another
             room
             ,
             )
             I
             found
             the
             Atmosphere
             to
             be
             at
             that
             time
             somewhat
             light
             ,
             the
             Quick-silver
             in
             it
             being
             in
             height
             but
             29.
             inches
             and
             an
             eighth
             ,
             which
             probably
             would
             have
             been
             the
             very
             height
             of
             the
             Quick-silver
             rais'd
             by
             the
             Engine
             ,
             if
             it
             had
             had
             time
             by
             standing
             to
             free
             it self
             from
             Bubbles
             .
          
           
             From
             whence
             we
             may
             conclude
             ,
             that
             Suction
             will
             elevate
             liquors
             in
             Pumps
             no
             higher
             then
             the
             weight
             of
             the
             Atmosphere
             is
             able
             to
             raise
             them
             ,
             since
             the
             closeness
             requisite
             in
             the
             Pump
             of
             our
             Engine
             to
             be
             stanch
             makes
             it
             very
             unlikely
             ,
             that
             by
             any
             ordinary
             Pump
             a
             more
             accurate
             Suction
             can
             be
             effected
             .
          
           
           
             I
             have
             nothing
             to
             adde
             about
             the
             related
             Experiment
             but
             this
             one
             ;
             that
             it
             may
             afford
             us
             a
             notable
             confirmation
             of
             the
             argument
             we
             formerly
             propos'd
             against
             them
             ,
             that
             ascrib'd
             the
             elevation
             and
             sustentation
             of
             the
             Quick-silver
             in
             the
             Torricellian
             Experiment
             to
             a
             certain
             rarified
             Air
             ,
             which
             the
             more
             highly
             it
             is
             rarified
             ,
             the
             greater
             power
             it
             acquires
             to
             attract
             Quick-silver
             ,
             and
             other
             contiguous
             Bodies
             ;
             for
             in
             our
             Experiment
             though
             by
             continuing
             to
             pump
             we
             can
             rarifie
             or
             distend
             more
             and
             more
             the
             Air
             in
             the
             Exhausting
             Siphon
             ,
             yet
             we
             were
             not
             able
             to
             raise
             the
             Mercury
             above
             30
             inches
             ,
             (
             which
             exceeds
             not
             the
             height
             to
             which
             the
             Atmosphere
             is
             able
             to
             elevate
             it
             ,
             )
             and
             this
             ,
             though
             ,
             the
             stagnant
             Mercury
             being
             exposed
             to
             the
             free
             Air
             ,
             it
             cannot
             be
             pretended
             (
             as
             in
             some
             other
             cases
             it
             may
             ,
             though
             not
             satisfactorily
             ,
             be
             done
             )
             that
             the
             Mercury
             cannot
             be
             raised
             higher
             ,
             without
             offering
             violence
             to
             the
             body
             incumbent
             on
             the
             stagnant
             Mercury
             :
             for
             in
             the
             Experiment
             we
             are
             considering
             if
             Nature
             should
             raise
             the
             Quick-silver
             higher
             and
             higher
             in
             the
             Pipe
             ,
             to
             succeed
             in
             the
             room
             of
             the
             Air
             that
             is
             withdrawn
             ;
             the
             formerly
             Stagnant
             Mercury
             ,
             that
             would
             on
             this
             occasion
             be
             rais'd
             ,
             might
             be
             immediately
             succeeded
             by
             the
             free
             and
             undilated
             Air
             ,
             so
             that
             Nature
             would
             be
             put
             to
             offer
             violence
             to
             the
             Quick-silver
             onely
             ,
             which
             if
             she
             were
             scrupulous
             to
             do
             ,
             what
             ayl'd
             her
             to
             raise
             it
             (
             as
             she
             did
             in
             our
             Tryal
             )
             against
             the
             inclinations
             of
             so
             ponderous
             a
             body
             ,
             to
             above
             29.
             
             Inches
             high
             ?
          
           
             
               Annotation
               .
            
             
               Though
               the
               Exhausting
               Siphon
               ,
               mentioned
               at
               the
               beginning
               of
               this
               Experiment
               ,
               may
               be
               easily
               enough
               conceiv'd
               by
               an
               attentive
               inspection
               of
               the
               Figure
               ,
               yet
               because
               I
               frequently
               make
               use
               of
               it
               in
               Pneumatical
               Experiments
               ,
               t
               will
               not
               be
               amiss
               to
               intimate
               here
               once
               for
               all
               these
               three
               particulars
               about
               it
               .
               1.
               
               That
               though
               the
               bending
               Pipe
               its
               self
               may
               be
               for
               some
               uses
               more
               conveniently
               made
               of
               Glass
               than
               of
               Metal
               ,
               because
               the
               Transparency
               of
               the
               former
               may
               inable
               us
               to
               discover
               what
               passes
               in
               it
               ;
               yet
               for
               
               the
               most
               part
               we
               choose
               to
               imploy
               Pipes
               of
               the
               latter
               sort
               ,
               because
               the
               others
               are
               so
               very
               subject
               to
               break
               .
               2.
               
               That
               t
               is
               convenient
               to
               make
               the
               longer
               leg
               of
               the
               Siphon
               a
               little
               larger
               at
               the
               bottom
               than
               the
               rest
               of
               the
               Pipe
               usually
               needs
               to
               be
               ,
               that
               it
               may
               the
               more
               commodiously
               admit
               the
               shank
               of
               a
               Stop-cock
               ,
               which
               is
               to
               be
               very
               carefully
               inserted
               with
               Cement
               ;
               by
               seasonably
               turning
               and
               returning
               of
               which
               Stop-cock
               ,
               the
               passage
               (
               for
               the
               Air
               )
               between
               the
               Engine
               and
               the
               Vessel
               to
               be
               exhausted
               is
               to
               be
               opened
               and
               shut
               .
               3.
               
               That
               though
               we
               sometimes
               content
               our selves
               to
               apply
               immediately
               the
               brass
               Siphon
               its
               self
               to
               the
               Engine
               ,
               by
               fastning
               with
               Cement
               the
               external
               shank
               of
               the
               Stop-cock
               to
               the
               Orifice
               of
               the
               little
               Pipe
               ,
               through
               which
               the
               Excuction
               of
               the
               Air
               is
               made
               ;
               yet
               the
               bended
               Pipe
               alone
               ,
               if
               it
               be
               not
               almost
               constantly
               held
               ,
               is
               so
               apt
               to
               be
               loosen'd
               by
               the
               motion
               of
               the
               Engine
               ,
               and
               the
               turning
               of
               the
               Stopcock
               ,
               (
               which
               frequently
               occasions
               Leaks
               ,
               and
               disturbs
               the
               Operation
               ,
               )
               that
               for
               the
               most
               part
               we
               make
               use
               of
               a
               Siphon
               consisting
               of
               a
               brass
               Pipe
               ,
               
               and
               Stop-cock
               ,
               and
               a
               Glass
               of
               6
               ,
               8
               ,
               or
               10
               Inches
               in
               height
               ,
               and
               of
               some
               such
               shape
               (
               for
               it
               need
               not
               be
               the
               very
               same
               )
               as
               that
               represented
               in
               the
               Figure
               :
               for
               by
               this
               means
               ,
               though
               the
               Exhaustion
               is
               because
               of
               this
               additional
               Glass
               ,
               somewhat
               longer
               in
               making
               ,
               yet
               it
               is
               more
               securely
               and
               uninterruptedly
               carried
               on
               by
               reason
               of
               the
               stability
               ,
               which
               the
               breadth
               of
               the
               lower
               Orifice
               of
               the
               Glass
               gives
               to
               the
               whole
               Instrument
               .
               Besides
               which
               ,
               we
               have
               these
               other
               conveniences
               ,
               that
               not
               onely
               the
               Siphon
               is
               hereby
               much
               lengthned
               ,
               which
               in
               divers
               Tryals
               is
               very
               fit
               ;
               but
               also
               that
               we
               may
               commodiously
               place
               in
               the
               Glassie
               part
               of
               this
               compounded
               Syphon
               a
               Gage
               ,
               whereby
               to
               discern
               from
               time
               to
               time
               how
               much
               the
               Air
               is
               drawn
               out
               of
               the
               Vessel
               to
               be
               exhausted
               .
            
          
        
         
           
           
             EXPERIMENT
             XII
             .
          
           
             About
             the
             differing
             Heights
             whereto
             Liquors
             will
             be
             elevated
             by
             Suction
             ,
             according
             to
             their
             several
             Specifick
             Gravities
             .
          
           
             IF
             ,
             when
             I
             was
             making
             the
             foregoing
             Experiment
             ,
             I
             had
             been
             able
             to
             procure
             a
             Pipe
             long
             enough
             ,
             I
             had
             tried
             to
             what
             height
             I
             could
             raise
             Water
             by
             Suction
             ,
             though
             I
             would
             have
             done
             it
             rather
             to
             satisfie
             Others
             then
             my self
             ,
             who
             scarce
             doubted
             ,
             but
             that
             as
             Water
             is
             (
             bulk
             for
             bulk
             )
             about
             14
             times
             lighter
             than
             Quick-silver
             :
             so
             it
             would
             have
             been
             rais'd
             by
             Suction
             to
             about
             four
             or
             five
             and
             thirty
             foot
             ,
             (
             which
             is
             14
             times
             as
             high
             as
             we
             were
             able
             to
             elevate
             the
             Quick-silver
             ,
             )
             and
             no
             higher
             .
             But
             being
             not
             furnished
             for
             the
             Tryal
             I
             would
             have
             made
             ,
             I
             thought
             fit
             to
             substitute
             another
             ,
             which
             would
             carry
             the
             former
             Experiment
             somewhat
             further
             .
             For
             whereas
             ,
             in
             That
             ,
             we
             shew'd
             how
             high
             the
             Atmosphere
             was
             able
             by
             its
             whole
             Gravitation
             to
             raise
             Quick-silver
             ;
             and
             whereas
             likewise
             that
             ,
             which
             appears
             in
             Monsieur
             Paschals
             Experiment
             ,
             is
             ,
             at
             what
             height
             the
             whole
             weight
             of
             the
             Atmosphere
             can
             sustain
             a
             Cylinder
             of
             Water
             :
             by
             the
             way
             that
             I
             thought
             on
             ,
             it
             would
             appear
             ,
             (
             which
             hath
             not
             yet
             (
             that
             I
             know
             of
             )
             been
             shewn
             ,
             )
             how
             a
             part
             of
             the
             Pressure
             of
             the
             Air
             would
             in
             perpendicular
             Pipes
             raise
             not
             onely
             the
             two
             mentioned
             Liquors
             ,
             but
             others
             also
             to
             Heights
             answerable
             to
             the
             degree
             of
             Pressure
             ,
             and
             proportionable
             to
             the
             specifick
             Gravities
             of
             the
             respective
             Liquors
             .
          
           
             To
             make
             this
             Tryal
             the
             more
             clear
             and
             free
             from
             exceptions
             ,
             I
             caus'd
             to
             be
             made
             and
             inserted
             to
             the
             shorter
             Leg
             of
             the
             above
             mentioned
             Exhausting
             Siphon
             a
             short
             Pipe
             ;
             which
             brancht
             it self
             equally
             to
             the
             right
             hand
             and
             the
             left
             ,
             
             as
             the
             adjoyning
             Figure
             declares
             .
             In
             which
             contrivance
             I
             aim'd
             at
             these
             two
             conveniences
             :
             one
             that
             I
             might
             exhaust
             two
             Glass-Canes
             at
             the
             same
             time
             ;
             and
             the
             other
             ,
             to
             prevent
             its
             being
             surmis'd
             that
             the
             Engine
             was
             not
             equally
             applied
             to
             both
             the
             Glasses
             to
             be
             exhausted
             .
             This
             
             additional
             Brass-pipe
             being
             carefully
             cemented
             into
             the
             Sucking
             Syphon
             ,
             we
             did
             to
             each
             of
             its
             two
             branches
             take
             care
             to
             have
             well
             fastned
             with
             the
             same
             Cement
             a
             Cylindrical
             Glass
             of
             about
             42
             Inches
             in
             length
             ,
             (
             that
             being
             somewhat
             near
             the
             height
             of
             our
             exhausting
             Syphon
             above
             the
             floor
             ,
             )
             the
             lower
             Orifice
             of
             one
             of
             these
             two
             Glasses
             being
             immerst
             in
             a
             vessel
             of
             stagnant
             Mercury
             ,
             and
             that
             of
             the
             other
             in
             a
             vessel
             of
             Water
             ,
             where
             care
             was
             taken
             by
             those
             I
             imploy'd
             ,
             that
             as
             the
             Tubes
             were
             chosen
             near
             of
             a
             bigness
             ,
             (
             which
             yet
             was
             not
             necessary
             ,
             )
             so
             the
             surfaces
             of
             the
             two
             different
             Liquors
             should
             be
             near
             of
             a
             height
             .
             This
             being
             done
             ,
             we
             began
             to
             pump
             warily
             and
             slowly
             ,
             till
             the
             Water
             in
             one
             of
             the
             Pipes
             was
             elevated
             to
             about
             42
             inches
             ,
             and
             then
             measuring
             the
             height
             of
             the
             Quick-silver
             ,
             in
             the
             other
             Pipe
             above
             the
             surface
             of
             the
             Stagnant
             Quick-silver
             ,
             we
             found
             it
             to
             be
             almost
             3
             Inches
             ;
             so
             that
             the
             Water
             was
             about
             14
             times
             as
             high
             as
             the
             Quick-silver
             .
             And
             to
             prosecute
             the
             Experiment
             a
             little
             further
             ,
             we
             very
             warily
             let
             in
             a
             little
             Air
             to
             the
             Exhausting
             Syphon
             ,
             and
             had
             the
             pleasure
             to
             see
             the
             two
             Liquors
             proportionably
             descend
             ,
             till
             turning
             the
             Stop-cock
             when
             the
             Water
             was
             about
             14
             inches
             high
             ,
             we
             thereby
             kept
             them
             from
             sinking
             any
             lower
             ,
             till
             we
             had
             measured
             the
             height
             of
             the
             Quick-silver
             ,
             which
             we
             found
             to
             be
             about
             one
             inch
             .
          
           
             We
             tried
             also
             the
             proportion
             of
             these
             two
             Liquors
             at
             other
             heights
             ,
             but
             could
             not
             easily
             measure
             thē
             so
             well
             as
             we
             did
             at
             those
             newly
             mentioned
             ;
             and
             therefore
             though
             there
             seem'd
             to
             be
             some
             slight
             variation
             ,
             yet
             we
             lookt
             upon
             it
             but
             as
             what
             might
             be
             well
             imputed
             to
             the
             difficulty
             of
             making
             such
             Experiments
             exactly
             ;
             and
             this
             displeas'd
             me
             not
             in
             these
             Tryals
             ,
             that
             whereas
             it
             was
             observ'd
             ,
             and
             somewhat
             wondred
             at
             ,
             that
             the
             Quick-silver
             for
             the
             most
             part
             seem'd
             to
             be
             somewhat
             (
             though
             but
             a
             very
             little
             )
             higher
             then
             the
             proportion
             of
             1
             to
             14
             required
             ,
             I
             had
             long
             before
             by
             particular
             Tryals
             found
             ,
             that
             though
             14
             and
             1
             be
             the
             nearest
             of
             small
             integer
             numbers
             that
             express
             the
             proportion
             between
             the
             Specifick
             Gravities
             of
             Quicksilver
             and
             Water
             ,
             yet
             the
             former
             of
             those
             Fluids
             (
             or
             at
             least
             that
             which
             I
             made
             my
             Tryals
             with
             )
             is
             not
             
             quite
             so
             heavy
             as
             this
             proportion
             supposes
             ,
             though
             I
             shall
             not
             here
             stay
             to
             determine
             precisely
             the
             difference
             ,
             having
             done
             it
             in
             another
             Tract
             ,
             where
             the
             method
             I
             imployed
             in
             the
             investigation
             of
             it
             is
             also
             set
             down
             .
          
           
             The
             above
             mentioned
             Experiment
             ,
             made
             by
             the
             help
             of
             our
             Engine
             ,
             as
             to
             Quick-silver
             and
             Water
             being
             confirmable
             by
             Tryals
             (
             to
             be
             by
             and-by
             mentioned
             )
             made
             in
             other
             Liquors
             ,
             affords
             our
             Hypothesis
             two
             considerable
             advantages
             above
             the
             vulgar
             doctrine
             of
             the
             Schools
             ,
             (
             for
             I
             do
             not
             apply
             what
             follows
             to
             all
             the
             Plenists
             ,
             )
             who
             ascribe
             the
             ascension
             of
             Liquors
             by
             Suction
             to
             a
             Traction
             made
             
               ob
               fugam
               vacui
            
             ,
             as
             they
             are
             wont
             to
             speak
             .
          
           
             For
             first
             it
             is
             manifestly
             agreeable
             to
             our
             Doctrine
             ,
             that
             ,
             since
             the
             Air
             ,
             according
             to
             It
             ,
             is
             a
             Fluid
             that
             is
             not
             void
             of
             Weight
             ,
             it
             should
             raise
             those
             Liquors
             that
             are
             lighter
             ,
             as
             Water
             ,
             higher
             then
             those
             that
             are
             ponderous
             ,
             as
             Quick-silver
             ;
             and
             that
             answerably
             to
             the
             disparity
             of
             their
             Weights
             ▪
             And
             secondly
             ,
             there
             is
             no
             reason
             why
             ,
             if
             the
             Air
             be
             withdrawn
             by
             Suction
             from
             Quick
             silver
             and
             Water
             ,
             there
             should
             be
             less
             left
             a
             vacuum
             above
             the
             one
             then
             above
             the
             other
             ,
             in
             case
             either
             of
             them
             succeed
             not
             in
             the
             place
             deserted
             by
             the
             Air
             ,
             and
             consequently
             when
             the
             Air
             is
             withdrawn
             out
             of
             both
             the
             forementioned
             Glass-pipes
             ,
             if
             there
             would
             be
             no
             vacuum
             in
             case
             no
             liquor
             should
             succeed
             it
             ,
             why
             does
             Nature
             needlesly
             to
             prevent
             a
             vacuum
             make
             the
             Water
             that
             is
             an
             heavy
             body
             ascend
             contrary
             to
             its
             own
             nature
             ,
             according
             to
             which
             it
             tends
             towards
             the
             Center
             of
             the
             Earth
             ?
             And
             if
             the
             succeeding
             of
             a
             liquor
             be
             necessary
             to
             prevent
             a
             vacuum
             ,
             how
             chance
             that
             Nature
             does
             not
             elevate
             the
             Quick-silver
             as
             well
             as
             the
             Water
             ,
             especially
             since
             t
             is
             manifest
             by
             the
             foregoing
             Experiment
             that
             she
             is
             able
             to
             raise
             that
             ponderous
             Liquor
             above
             26
             inches
             higher
             than
             she
             did
             in
             the
             Experiment
             we
             are
             now
             discoursing
             of
             .
          
           
             Perhaps
             it
             would
             not
             be
             amiss
             to
             take
             notice
             ,
             on
             this
             occasion
             ,
             that
             among
             other
             applications
             of
             this
             Experiment
             it
             may
             be
             made
             somewhat
             useful
             to
             estimate
             the
             differing
             Gravities
             of
             liquors
             ,
             to
             
             w
             ch
             purpose
             I
             caus'd
             to
             be
             put
             under
             the
             bottom
             of
             the
             forementioned
             Glass
             pipes
             two
             vessels
             ,
             the
             one
             with
             fresh
             water
             ,
             &
             the
             other
             with
             the
             like
             water
             impregnated
             with
             a
             good
             proportion
             of
             Sea-salt
             that
             I
             had
             caus'd
             to
             be
             dissolv'd
             in
             it
             ,
             for
             want
             of
             Sea-water
             ,
             which
             I
             would
             rather
             have
             imploy'd
             .
             And
             I
             found
             ,
             that
             when
             the
             fresh
             water
             was
             rais'd
             to
             about
             42
             inches
             ,
             the
             Saline
             solution
             had
             not
             fully
             reacht
             to
             40.
             
          
           
             But
             though
             this
             difference
             were
             double
             to
             that
             which
             the
             proportion
             and
             Gravity
             betwixt
             our
             Sea-water
             and
             fresh
             water
             would
             have
             required
             ,
             yet
             to
             make
             the
             disparity
             more
             evident
             ,
             and
             also
             because
             I
             would
             be
             able
             the
             better
             to
             guess
             at
             the
             proportion
             of
             the
             dissolv'd
             Salt
             by
             making
             it
             as
             great
             as
             I
             could
             ,
             I
             caus'd
             an
             unusual
             Brine
             to
             be
             made
             ,
             by
             suffering
             Sea-salt
             to
             deliquate
             in
             the
             moist
             Air.
             And
             having
             applyed
             this
             Liquor
             and
             fresh
             water
             to
             the
             two
             already
             mentioned
             Pipes
             ,
             and
             proceeded
             after
             the
             former
             manner
             ,
             we
             found
             that
             when
             the
             pure
             water
             was
             elevated
             to
             near
             42
             Inches
             ,
             the
             liquor
             of
             Sea-salt
             wanted
             about
             7.
             
             Inches
             and
             a
             quarter
             of
             that
             height
             ;
             and
             when
             the
             water
             was
             made
             to
             subside
             to
             the
             middle
             of
             its
             Pipe
             ,
             or
             thereabouts
             ,
             the
             Saline
             liquor
             in
             the
             other
             Pipe
             was
             between
             3
             and
             4
             inches
             lower
             then
             it
             .
          
           
             I
             would
             have
             tryed
             the
             difference
             between
             these
             Liquors
             and
             Oyl
             ,
             but
             the
             Coldness
             of
             the
             Weather
             was
             unfavourable
             to
             such
             a
             Tryal
             :
             but
             to
             shew
             a
             far
             greater
             Disparity
             then
             That
             would
             have
             done
             betwixt
             the
             height
             of
             Liquors
             of
             unequal
             Gravities
             ,
             I
             took
             fair
             Water
             ,
             and
             a
             liquor
             made
             of
             the
             Salt
             of
             Pot-ashes
             suffered
             to
             run
             in
             a
             Sellar
             
               per
               deliquium
            
             ,
             (
             this
             being
             one
             of
             the
             ponderousest
             Liquors
             I
             have
             prepar'd
             ,
             )
             and
             having
             proceeded
             as
             in
             the
             former
             Tryals
             ,
             I
             found
             that
             when
             the
             common
             Water
             was
             about
             42
             inches
             high
             ,
             the
             newly
             mention'd
             Solution
             wanted
             somewhat
             of
             30
             inches
             ;
             and
             when
             the
             Water
             was
             made
             to
             subside
             to
             the
             middle
             of
             its
             Pipe
             ,
             or
             thereabouts
             ,
             the
             deliquated
             Liquor
             was
             between
             6
             and
             7
             inches
             lower
             then
             it
             .
          
           
             I
             had
             some
             thoughts
             ,
             when
             I
             applied
             my self
             to
             make
             these
             Tryals
             ,
             to
             examine
             how
             well
             we
             could
             by
             this
             new
             way
             compare
             
             the
             Saltness
             of
             the
             waters
             of
             several
             Seas
             ,
             and
             those
             also
             of
             Salt-springs
             ;
             and
             likewise
             whether
             ,
             and
             (
             if
             any
             thing
             near
             )
             how
             far
             we
             might
             by
             this
             Method
             determine
             the
             proportion
             of
             the
             more
             simple
             Liquors
             that
             may
             be
             mingled
             in
             compounded
             ones
             ,
             as
             in
             the
             mixture
             of
             Water
             and
             Wine
             ,
             Vinegar
             and
             Water
             ,
             &c.
             but
             being
             not
             provided
             with
             Instruments
             fit
             for
             such
             nice
             Tryals
             ,
             and
             a
             mischance
             having
             impair'd
             the
             Glasses
             lately
             mentioned
             before
             the
             last
             Tryals
             were
             quite
             ended
             ,
             and
             having
             soon
             after
             broken
             one
             of
             them
             ,
             I
             laid
             aside
             those
             Thoughts
             .
          
        
         
           
             EXPERIMENT
             XIII
             .
          
           
             About
             the
             Heights
             to
             which
             Water
             and
             Mercury
             may
             be
             rais'd
             ,
             proportionably
             to
             their
             specifick
             Gravities
             ,
             by
             the
             Spring
             of
             the
             Air.
             
          
           
             IN
             prosecution
             of
             the
             Parallel
             formerly
             begun
             ,
             betwixt
             the
             Effects
             of
             the
             Weight
             of
             the
             Atmosphere
             ,
             and
             the
             Spring
             of
             included
             Air
             ,
             we
             thought
             fit
             after
             the
             foregoing
             to
             make
             the
             following
             Experiment
             .
          
           
             We
             took
             a
             strong
             Glass-bottle
             ,
             capable
             to
             hold
             above
             a
             Pint
             of
             Water
             ,
             and
             having
             in
             the
             bottom
             of
             it
             lodg'd
             a
             convenient
             quantity
             of
             Mercury
             ,
             we
             pour'd
             on
             it
             a
             greater
             quantity
             of
             Water
             ,
             (
             because
             this
             Liquor
             was
             to
             be
             impell'd
             up
             many
             times
             higher
             than
             the
             other
             ,
             )
             and
             having
             provided
             two
             slender
             Glass-pipes
             ,
             each
             open
             at
             both
             ends
             ,
             we
             so
             plac'd
             and
             fastned
             them
             ,
             by
             means
             of
             the
             Cement
             wherewith
             we
             choak'd
             the
             upper
             part
             of
             the
             neck
             of
             the
             Bottle
             ,
             that
             the
             shorter
             of
             the
             Pipes
             had
             its
             lower
             Orifice
             immerst
             beneath
             the
             surface
             of
             the
             Quick-silver
             ,
             and
             the
             longer
             Pipe
             reacht
             not
             quite
             so
             low
             as
             that
             Surface
             ,
             and
             so
             was
             immerst
             but
             in
             the
             Water
             ,
             by
             which
             contrivance
             we
             avoided
             the
             necessity
             of
             having
             two
             distinct
             vessels
             for
             our
             two
             stagnant
             Liquors
             ,
             which
             would
             have
             been
             inconvenient
             in
             regard
             of
             the
             slenderness
             of
             the
             upper
             part
             of
             our
             Receiver
             .
             This
             done
             ,
             we
             conveyed
             the
             Bottle
             
             into
             a
             fitly
             shap'd
             Receiver
             ,
             (
             formerly
             describ'd
             at
             the
             first
             Experiment
             ,
             )
             and
             having
             begun
             to
             pump
             out
             the
             Air
             ,
             we
             took
             notice
             to
             what
             heights
             the
             Quick-silver
             and
             Water
             were
             impell'd
             up
             in
             their
             respective
             Tubes
             ,
             on
             which
             we
             had
             before
             made
             marks
             from
             inch
             to
             inch
             with
             hard
             Wax
             ,
             (
             that
             they
             might
             not
             be
             remov'd
             by
             wet
             or
             rubbing
             ,
             )
             and
             we
             observ'd
             ,
             that
             when
             the
             Quicksilver
             was
             impell'd
             up
             to
             two
             inches
             ,
             the
             Water
             was
             rais'd
             to
             about
             eight
             and
             twenty
             ;
             and
             when
             the
             Quick-silver
             was
             about
             one
             inch
             high
             ,
             the
             Water
             was
             about
             fourteen
             .
             I
             say
             ,
             
               about
               ,
               partly
            
             because
             some
             allowances
             must
             be
             made
             for
             the
             sinking
             of
             the
             Superficies
             of
             the
             Stagnant
             Quicksilver
             ,
             and
             the
             greater
             subsidence
             of
             that
             of
             the
             stagnant
             Water
             ,
             by
             reason
             of
             the
             Liquors
             impell'd
             into
             the
             two
             Pipes
             ;
             partly
             because
             that
             the
             breadth
             of
             the
             Mark
             of
             wax
             was
             considerable
             ,
             when
             the
             Quick-silver
             was
             but
             about
             an
             inch
             high
             ,
             and
             so
             made
             it
             difficult
             to
             discern
             the
             exact
             height
             of
             the
             Metal
             ,
             when
             the
             water
             was
             fallen
             down
             to
             fourteen
             inches
             :
             especially
             in
             regard
             that
             the
             Quick-silver
             never
             ascending
             so
             high
             as
             the
             neck
             of
             the
             Bottle
             ,
             (
             which
             the
             water
             left
             far
             beneath
             it
             ,
             )
             the
             thickness
             of
             the
             Receiver
             ,
             and
             that
             of
             so
             strong
             a
             Bottle
             made
             it
             difficult
             to
             discern
             so
             clearly
             the
             station
             of
             the
             Quick-silver
             as
             I
             could
             have
             wished
             .
          
        
         
           
             EXPERIMENT
             XIV
             .
          
           
             About
             the
             Heights
             answerable
             to
             their
             respective
             Gravities
             ,
             to
             which
             Mercury
             and
             Water
             will
             subside
             ,
             upon
             the
             withdrawing
             of
             the
             Spring
             of
             the
             Air.
             
          
           
             FOr
             the
             further
             illustration
             of
             the
             Doctrine
             propos'd
             in
             the
             last
             and
             some
             of
             the
             foregoing
             Experiments
             ,
             about
             the
             raising
             and
             sustentation
             of
             Liquors
             in
             Pipes
             by
             the
             Pressure
             of
             the
             Air
             ;
             I
             thought
             it
             not
             unfit
             to
             make
             the
             following
             Tryal
             ,
             though
             it
             were
             easie
             to
             foresee
             in
             this
             peculiar
             Experiment
             a
             peculiar
             difficulty
             .
          
           
           
             We
             caus'd
             then
             to
             be
             convey'd
             into
             a
             fitly
             shap'd
             Receiver
             two
             Pipes
             of
             Glass
             very
             uneven
             in
             length
             ,
             but
             each
             of
             them
             seal'd
             at
             one
             end
             ,
             the
             shorter
             Tube
             was
             fill'd
             with
             Mercury
             ,
             and
             inverted
             into
             a
             small
             Glass
             Jarr
             ,
             wherein
             a
             sufficient
             quantity
             of
             that
             Liquor
             had
             been
             before
             lodg'd
             :
             the
             longer
             Pipe
             was
             fill'd
             with
             common
             Water
             ,
             and
             inverted
             into
             a
             larger
             Glass
             ,
             wherein
             likewise
             a
             fit
             proportion
             of
             the
             same
             Liquor
             had
             been
             put
             .
          
           
             Then
             the
             Receiver
             being
             closely
             cemented
             on
             to
             the
             Engine
             ,
             the
             Air
             was
             pump'd
             out
             for
             a
             pretty
             while
             before
             the
             Mercury
             began
             to
             subside
             ;
             but
             when
             it
             was
             so
             far
             withdrawn
             ,
             that
             its
             Pressure
             was
             no
             longer
             able
             to
             keep
             up
             a
             Mercurial
             Cylinder
             of
             that
             height
             ,
             that
             liquid
             Metal
             began
             to
             sink
             ;
             the
             Water
             in
             the
             other
             Tube
             ,
             though
             this
             were
             three
             times
             as
             long
             ,
             still
             retaining
             its
             full
             height
             .
             But
             when
             the
             Quick-silver
             was
             fallen
             so
             low
             ,
             as
             to
             be
             but
             between
             three
             &
             four
             inches
             above
             the
             surface
             of
             the
             Stagnant
             Quick-silver
             ,
             the
             Water
             also
             began
             to
             subside
             ,
             but
             sooner
             then
             according
             to
             the
             laws
             of
             meer
             Staticks
             it
             ought
             to
             have
             done
             ,
             because
             many
             Aerial
             Particles
             emerging
             from
             the
             body
             of
             the
             Water
             to
             the
             upper
             part
             of
             the
             Glass
             ,
             did
             by
             their
             Spring
             concurr
             with
             the
             Gravity
             of
             the
             water
             to
             depress
             this
             Liquor
             .
             And
             so
             when
             the
             Quick-silver
             was
             three
             inches
             above
             the
             stagnant
             Mercury
             ,
             the
             water
             in
             the
             other
             Pipe
             was
             fallen
             divers
             inches
             beneath
             42
             ,
             and
             several
             inches
             beneath
             28
             when
             the
             Mercury
             had
             subsided
             an
             inch
             lower
             .
             But
             this
             being
             no
             more
             then
             was
             to
             be
             expected
             ,
             after
             we
             had
             caus'd
             the
             Pumping
             to
             be
             a
             while
             continued
             ,
             to
             free
             the
             water
             the
             better
             from
             the
             latitant
             Air
             ,
             we
             let
             in
             the
             external
             Air
             ,
             and
             having
             thereby
             impell'd
             up
             again
             both
             the
             Liquors
             into
             their
             Pipes
             ,
             and
             remov'd
             the
             Receiver
             we
             took
             out
             those
             Pipes
             ,
             and
             inverting
             each
             of
             them
             again
             to
             let
             out
             the
             Air
             ,
             (
             for
             even
             that
             wich
             held
             the
             Quick-silver
             had
             got
             a
             small
             Bubble
             ,
             though
             inconsiderable
             in
             comparison
             of
             the
             Air
             that
             had
             got
             up
             out
             of
             the
             Water
             ,
             )
             we
             fill'd
             each
             of
             them
             with
             a
             little
             of
             the
             restagnant
             Liquor
             belonging
             to
             it
             ,
             and
             inverting
             each
             Tube
             once
             more
             into
             its
             proper
             liquor
             ,
             we
             repeated
             the
             Experiment
             ,
             and
             found
             it
             ,
             as
             it
             
             seem'd
             ,
             to
             require
             more
             pumping
             then
             before
             to
             make
             the
             Liquors
             begin
             to
             subside
             ;
             so
             that
             when
             the
             Mercury
             was
             fallen
             to
             three
             inches
             ,
             or
             two
             ,
             or
             one
             ,
             the
             water
             subsided
             so
             near
             to
             the
             heights
             of
             42
             ,
             28
             ,
             or
             14
             inches
             ,
             that
             we
             saw
             no
             sufficient
             cause
             to
             hinder
             us
             from
             supposing
             ,
             that
             the
             litle
             differences
             that
             appear'd
             between
             the
             several
             heights
             of
             the
             Quick-silver
             ,
             and
             fourteen
             times
             as
             great
             heights
             of
             the
             Water
             (
             which
             fell
             somewhat
             lower
             than
             its
             proportion
             in
             Gravity
             required
             )
             proceeded
             from
             some
             Aerial
             Corpuscles
             yet
             remaining
             ,
             in
             spite
             of
             all
             we
             had
             done
             ,
             in
             the
             water
             ,
             and
             by
             their
             Spring
             ,
             though
             but
             faint
             ,
             when
             once
             they
             had
             emerg'd
             to
             the
             upper
             part
             of
             the
             Glass
             ,
             furthering
             a
             little
             the
             depression
             of
             it
             :
             not
             now
             to
             mention
             lesser
             Circumstances
             ,
             particularly
             ,
             that
             the
             surface
             of
             the
             stagnant
             Water
             did
             not
             inconsiderably
             rise
             by
             the
             accession
             of
             the
             Water
             lately
             in
             the
             Pipe
             ;
             whereby
             the
             Cylinder
             of
             water
             ,
             rais'd
             above
             that
             surface
             ,
             became
             by
             so
             much
             the
             shorter
             .
             However
             Your
             Lordship
             may
             ,
             if
             You
             think
             fit
             ,
             cause
             the
             Experiment
             to
             be
             reiterated
             ,
             which
             I
             could
             not
             so
             well
             do
             ,
             by
             reason
             of
             a
             mischance
             that
             befell
             the
             Receiver
             .
          
        
         
           
             EXPERIMENT
             XV.
             
          
           
             About
             the
             greatest
             height
             to
             which
             Water
             can
             be
             rais'd
             by
             Attraction
             or
             Sucking
             Pumps
             .
          
           
             SInce
             the
             making
             and
             the
             writing
             of
             the
             foregoing
             Experiments
             ,
             having
             met
             with
             an
             opportunity
             to
             borrow
             a
             place
             somewhat
             convenient
             to
             make
             a
             Tryal
             to
             what
             height
             Water
             may
             be
             rais'd
             by
             Pumping
             ;
             I
             thought
             not
             fit
             to
             neglect
             it
             .
             For
             though
             both
             by
             the
             consideration
             of
             our
             Hypothesis
             ,
             to
             whose
             truth
             so
             many
             Phaenomena
             bear
             witness
             ;
             and
             though
             particularly
             by
             the
             Consequences
             deduceable
             from
             the
             three
             last
             recited
             Experiments
             I
             were
             kept
             from
             doubting
             what
             the
             event
             would
             be
             ,
             yet
             I
             thought
             it
             worth
             while
             to
             make
             the
             Tryal
             .
          
           
           
             I
             know
             what
             is
             said
             to
             have
             been
             the
             Complaint
             of
             some
             Pump-makers
             .
             But
             I
             confess
             the
             Phaenomenon
             ,
             't
             was
             grounded
             on
             ,
             seem'd
             not
             to
             me
             to
             be
             certainly
             enough
             deliver'd
             by
             a
             Writer
             or
             two
             ,
             that
             mention
             what
             they
             complain'd
             of
             ;
             and
             their
             observation
             seems
             not
             to
             have
             been
             made
             determinately
             or
             carefully
             enough
             for
             a
             matter
             of
             this
             moment
             .
             Since
             that
             which
             they
             complain
             of
             seems
             to
             have
             been
             in
             general
             ,
             that
             they
             could
             not
             by
             pumping
             raise
             Water
             to
             what
             height
             they
             please
             ,
             as
             the
             common
             Opinion
             of
             Philosophers
             about
             Natures
             
               fuga
               vacui
            
             made
             them
             expect
             they
             might
             .
             And
             it
             may
             well
             have
             happen'd
             ,
             that
             as
             they
             endeavoured
             onely
             to
             raise
             it
             to
             the
             height
             their
             occasions
             required
             ,
             so
             all
             that
             their
             Disappointment
             manifested
             ,
             was
             ,
             that
             they
             could
             not
             raise
             it
             to
             that
             particular
             height
             :
             which
             did
             not
             determine
             ,
             whether
             if
             the
             Pump
             had
             been
             a
             Foot
             or
             a
             Yard
             shorter
             ,
             the
             Water
             would
             then
             have
             been
             elevated
             to
             the
             upper
             part
             of
             it
             or
             no
             :
             but
             that
             which
             I
             chiefly
             consider
             is
             ,
             that
             these
             being
             but
             Tradesmen
             ,
             that
             did
             not
             work
             according
             to
             the
             Dictates
             of
             ,
             or
             with
             design
             to
             satisfie
             ,
             a
             Philosophical
             Curiosity
             ,
             we
             may
             justly
             suspect
             ,
             that
             their
             Pumps
             were
             not
             sufficiently
             stanch
             ,
             nor
             the
             Operation
             Critically
             enough
             perform'd
             and
             taken
             notice
             of
             .
          
           
             Wherefore
             ,
             partly
             because
             a
             Tryal
             of
             such
             moment
             seem'd
             not
             to
             have
             yet
             been
             duely
             made
             by
             any
             ;
             and
             partly
             because
             the
             varying
             weight
             of
             the
             Atmosphere
             was
             not
             (
             that
             appears
             )
             known
             ,
             nor
             (
             consequently
             )
             taken
             into
             consideration
             by
             the
             ingenious
             Monsieur
             Paschal
             in
             his
             famous
             Experiment
             ,
             which
             yet
             is
             but
             analogous
             to
             this
             ;
             and
             partly
             because
             some
             very
             Late
             as
             well
             as
             Learned
             Writers
             have
             not
             acquiesc'd
             in
             his
             Experiment
             ,
             but
             do
             adhere
             to
             the
             old
             Doctrine
             of
             the
             Schools
             ,
             which
             would
             have
             Water
             raiseable
             in
             Pumps
             to
             any
             height
             ,
             
               ob
               fugam
               vacut
            
             ,
             (
             as
             they
             speak
             ,
             )
             I
             thought
             fit
             to
             make
             the
             best
             shift
             I
             could
             to
             make
             the
             Tryal
             ,
             of
             which
             I
             now
             proceed
             to
             give
             Your
             Lordship
             an
             Account
             .
          
           
             The
             place
             I
             borrowed
             for
             this
             purpose
             was
             a
             flat
             Roof
             about
             30
             foot
             high
             from
             the
             ground
             ,
             and
             with
             Railes
             along
             the
             edges
             
             of
             it
             .
             The
             Tube
             we
             made
             use
             of
             should
             have
             been
             of
             Glass
             ,
             if
             we
             could
             have
             procured
             one
             long
             and
             strong
             enough
             .
             But
             that
             being
             exceeding
             difficult
             ,
             especially
             for
             me
             ,
             who
             was
             not
             near
             a
             Glass-house
             ,
             we
             were
             fain
             to
             cause
             a
             Tin-man
             to
             make
             several
             Pipes
             of
             above
             an
             inch
             bore
             ,
             (
             for
             of
             a
             great
             length
             't
             was
             alleadg'd
             they
             could
             not
             be
             made
             slenderer
             ,
             )
             and
             as
             long
             as
             he
             could
             ,
             of
             Tin
             or
             Laton
             ,
             as
             they
             call
             thin
             Plates
             of
             Iron
             Tinn'd
             over
             ;
             and
             these
             being
             very
             carefully
             soder'd
             together
             made
             up
             one
             Pipe
             ,
             of
             about
             one
             or
             two
             and
             thirty
             foot
             long
             ,
             which
             being
             tied
             to
             a
             Pole
             we
             tried
             with
             Water
             whether
             it
             were
             stanch
             ,
             and
             by
             the
             effluxions
             of
             that
             Liquor
             finding
             where
             the
             Leaks
             were
             ,
             we
             caus'd
             them
             to
             be
             stopt
             with
             Soder
             ,
             and
             then
             for
             greater
             security
             the
             whole
             Pipe
             ,
             especially
             at
             the
             Commissures
             ,
             was
             diligently
             cas'd
             over
             with
             our
             close
             black
             Cement
             ,
             upon
             which
             Plaister
             of
             Paris
             was
             strewed
             to
             keep
             it
             from
             sticking
             to
             their
             hands
             or
             cloaths
             that
             should
             manage
             the
             Pipe.
             At
             the
             upper
             part
             of
             which
             was
             very
             carefully
             fastned
             with
             the
             like
             Cement
             a
             strong
             Pipe
             of
             Glass
             ,
             of
             between
             2
             and
             3
             foot
             in
             length
             ,
             that
             we
             might
             see
             what
             should
             happen
             at
             the
             top
             of
             the
             water
             .
             And
             to
             the
             upper
             part
             of
             this
             Pipe
             was
             (
             with
             Cement
             ,
             and
             by
             the
             means
             of
             a
             short
             elbow
             of
             Tin
             )
             very
             closely
             fastned
             another
             Pipe
             of
             the
             same
             Metal
             ,
             consisting
             of
             two
             pieces
             ,
             making
             a
             right
             Angle
             with
             one
             another
             ,
             whereof
             the
             upper
             part
             was
             parallel
             to
             the
             Horizon
             ,
             and
             the
             other
             ,
             which
             was
             parallel
             to
             the
             Glass-pipe
             ,
             reacht
             down
             to
             the
             Engine
             ,
             which
             was
             plac'd
             on
             the
             flat
             Roof
             ,
             and
             was
             to
             be
             with
             good
             Cement
             sollicitously
             fastned
             to
             the
             lower
             end
             of
             this
             descending
             part
             of
             the
             Pipe
             ,
             whose
             Horizontal
             leg
             was
             supported
             by
             a
             piece
             of
             Wood
             ,
             nail'd
             to
             the
             above
             mentioned
             Rails
             ;
             as
             the
             Tube
             also
             was
             kept
             from
             overmuch
             shaking
             by
             a
             board
             ,
             (
             fasten'd
             to
             the
             same
             Rails
             ,
             )
             and
             having
             a
             deep
             Notch
             cut
             in
             it
             ,
             for
             the
             Tube
             to
             be
             inserted
             into
             .
          
           
             This
             Apparatus
             being
             made
             ,
             
             and
             the
             whole
             Tube
             with
             its
             Pole
             erected
             along
             the
             Wall
             ,
             and
             fastned
             with
             strings
             and
             other
             helps
             ,
             and
             the
             descending
             Pipe
             being
             carefully
             cemented
             on
             
             to
             the
             Engine
             ,
             there
             was
             plac'd
             under
             the
             bottom
             of
             the
             long
             Tube
             a
             convenient
             vessel
             ,
             whereinto
             so
             much
             Water
             was
             poured
             ,
             as
             reach'd
             a
             great
             way
             above
             the
             orifice
             of
             the
             Pipe
             ,
             and
             one
             was
             appointed
             to
             stand
             by
             to
             pour
             in
             more
             as
             need
             should
             require
             ,
             that
             the
             vessel
             might
             be
             still
             kept
             competently
             full
             .
          
           
             After
             all
             this
             the
             Pump
             was
             set
             on
             work
             ,
             but
             when
             the
             water
             had
             been
             raised
             to
             a
             great
             height
             ,
             and
             consequently
             had
             a
             great
             Pressure
             against
             the
             sides
             of
             the
             Tube
             ,
             a
             small
             Leak
             or
             two
             was
             either
             discovered
             or
             made
             ,
             which
             without
             moving
             the
             Tube
             we
             caus'd
             to
             be
             well
             stopt
             ,
             by
             one
             that
             was
             sent
             up
             a
             Ladder
             to
             apply
             store
             of
             Cement
             where
             it
             was
             requisite
             .
          
           
             Wherefore
             at
             length
             we
             were
             able
             after
             a
             pretty
             number
             of
             Exuctions
             ,
             to
             raise
             the
             Water
             to
             the
             middle
             of
             the
             Glass-pipe
             above
             mentioned
             ,
             but
             not
             without
             great
             store
             of
             bubbles
             ,
             (
             made
             by
             the
             Air
             formerly
             conceal'd
             in
             the
             pores
             of
             the
             water
             ,
             and
             now
             emerging
             ,
             )
             which
             for
             a
             pretty
             while
             kept
             a
             kind
             of
             Foam
             upon
             the
             surface
             of
             it
             ,
             (
             fresh
             ones
             continually
             succeeding
             those
             that
             broke
             .
             )
             And
             finding
             the
             Engine
             and
             Tube
             as
             stanch
             as
             could
             be
             well
             expected
             ,
             I
             thought
             it
             a
             fit
             season
             to
             trie
             what
             was
             the
             utmost
             height
             to
             which
             Water
             could
             by
             Suction
             be
             elevated
             ;
             and
             therefore
             though
             the
             Pump
             seem'd
             to
             have
             been
             plyed
             enough
             already
             ,
             yet
             for
             further
             satisfaction
             ,
             when
             the
             Water
             was
             within
             few
             inches
             of
             the
             top
             of
             the
             Glass
             ,
             I
             caus'd
             20
             Exuctions
             more
             to
             be
             nimbly
             made
             ,
             to
             be
             sure
             that
             the
             water
             should
             be
             raised
             as
             high
             as
             by
             our
             Pump
             it
             could
             be
             possibly
             .
             And
             having
             taken
             notice
             where
             the
             Surface
             rested
             ,
             and
             caus'd
             a
             piece
             of
             Cement
             to
             be
             stuck
             near
             it
             ,
             (
             for
             we
             could
             not
             then
             come
             to
             reach
             it
             exactly
             ,
             )
             and
             descending
             to
             the
             Ground
             where
             the
             stagnant
             water
             stood
             ,
             we
             caus'd
             a
             string
             to
             be
             let
             down
             ,
             with
             a
             weight
             hanging
             at
             the
             end
             of
             it
             ,
             which
             we
             applied
             to
             a
             mark
             ,
             that
             had
             been
             purposely
             made
             at
             that
             part
             of
             the
             (
             Metalline
             )
             Tube
             ,
             which
             the
             superficies
             of
             the
             stagnant
             water
             had
             rested
             at
             ,
             when
             the
             water
             was
             elevated
             to
             its
             full
             height
             :
             and
             the
             other
             end
             of
             the
             string
             being
             ,
             by
             him
             that
             let
             it
             down
             ,
             applied
             to
             that
             part
             of
             the
             Glass
             ,
             as
             near
             as
             he
             could
             guess
             ,
             
             where
             the
             upper
             part
             of
             the
             Water
             reacht
             ,
             the
             Weight
             was
             pull'd
             up
             ;
             and
             the
             length
             of
             the
             string
             ,
             and
             (
             consequently
             )
             the
             height
             of
             the
             Cylinder
             of
             Water
             was
             measur'd
             ,
             which
             amounted
             to
             33
             foot
             ,
             and
             about
             6
             inches
             .
             Which
             done
             ,
             I
             return'd
             to
             my
             lodging
             ,
             which
             was
             not
             far
             off
             ,
             to
             look
             upon
             the
             Baroscope
             ,
             to
             be
             informed
             of
             the
             present
             weight
             of
             the
             Atmosphere
             ,
             which
             I
             found
             to
             be
             but
             moderate
             ,
             the
             Quick-silver
             standing
             at
             29
             inches
             ,
             and
             between
             2
             and
             3
             eights
             of
             an
             inch
             .
             This
             being
             taken
             notice
             of
             ,
             it
             was
             not
             difficult
             to
             compare
             the
             success
             of
             the
             Experiment
             with
             our
             Hypothesis
             .
             For
             if
             we
             suppose
             the
             most
             received
             proportion
             in
             bulk
             between
             Cylinders
             of
             Quick-silver
             and
             of
             Water
             of
             the
             same
             weight
             ,
             namely
             that
             of
             1
             to
             14
             ,
             the
             height
             of
             the
             water
             ought
             to
             have
             been
             34
             foot
             and
             about
             two
             inches
             ,
             which
             is
             about
             8
             inches
             greater
             than
             we
             found
             it
             .
             But
             then
             Your
             Lordship
             may
             be
             pleased
             to
             remember
             ,
             that
             I
             formerly
             noted
             (
             before
             ever
             I
             made
             this
             Experiment
             )
             that
             I
             did
             not
             allow
             the
             proportion
             betwixt
             Mercury
             and
             Water
             (
             at
             least
             such
             water
             as
             I
             made
             my
             Tryals
             with
             )
             to
             be
             altogether
             so
             great
             ,
             and
             though
             in
             ordinary
             Experiments
             we
             may
             with
             very
             litle
             inconvenience
             make
             use
             of
             that
             proportion
             to
             avoid
             fractions
             ,
             yet
             in
             so
             tall
             a
             Cylinder
             of
             Water
             as
             ours
             was
             ,
             the
             difference
             is
             too
             considerable
             to
             be
             neglected
             .
             If
             therefore
             in
             stead
             of
             making
             an
             Inch
             of
             Quick-silver
             equivalent
             to
             14
             inches
             of
             Water
             ,
             we
             abate
             but
             a
             quarter
             of
             an
             inch
             ,
             which
             is
             but
             a
             56
             part
             of
             the
             height
             of
             the
             Water
             ,
             this
             abatement
             being
             repeated
             29
             times
             and
             a
             quarter
             ,
             will
             amount
             to
             7
             inches
             ,
             and
             above
             a
             quarter
             ,
             which
             added
             to
             the
             former
             height
             of
             the
             Water
             ,
             namely
             33
             Foot
             and
             6
             inches
             ,
             will
             make
             up
             34
             foot
             and
             above
             an
             inch
             ;
             so
             that
             the
             difference
             between
             the
             height
             of
             the
             Mercury
             sustain'd
             by
             the
             weight
             of
             the
             Atmosphere
             in
             the
             Baroscope
             ,
             and
             that
             of
             the
             Water
             rais'd
             and
             sustain'd
             by
             the
             Pressure
             of
             the
             same
             Atmosphere
             in
             the
             long
             Tube
             did
             not
             appear
             to
             differ
             more
             than
             an
             Inch
             or
             two
             from
             the
             proportion
             they
             ought
             to
             have
             had
             ,
             according
             to
             the
             difference
             of
             their
             specifick
             Gravities
             .
             And
             though
             in
             our
             Experiment
             the
             difference
             had
             been
             
             greater
             ,
             provided
             it
             exceeded
             not
             8
             or
             10
             Inches
             ,
             it
             would
             not
             have
             been
             strange
             :
             partly
             ,
             because
             of
             the
             difficulty
             of
             measuring
             all
             things
             so
             exactly
             in
             such
             an
             Experiment
             ,
             partly
             because
             as
             Waters
             are
             not
             all
             of
             the
             same
             weight
             ,
             so
             a
             little
             disparity
             of
             it
             in
             so
             long
             a
             Cylinder
             may
             be
             considerable
             ,
             and
             partly
             (
             and
             perhaps
             chiefly
             )
             because
             the
             Air
             flying
             out
             of
             the
             bubbles
             ,
             that
             rose
             out
             of
             so
             great
             a
             quantity
             of
             water
             ,
             and
             breaking
             at
             the
             top
             of
             it
             ,
             and
             so
             near
             that
             of
             the
             Tube
             ,
             might
             by
             its
             Spring
             (
             though
             but
             very
             weak
             )
             assisting
             the
             weight
             of
             so
             much
             water
             ,
             somewhat
             (
             though
             not
             much
             )
             hinder
             the
             utmost
             elevation
             of
             that
             Liquor
             .
             But
             our
             Experiment
             did
             not
             make
             it
             needful
             for
             me
             to
             insist
             on
             these
             considerations
             ,
             and
             the
             inconsiderable
             difference
             that
             was
             betwixt
             the
             height
             of
             the
             water
             we
             found
             ,
             and
             that
             which
             might
             have
             been
             wish'd
             ,
             did
             rather
             countenance
             then
             at
             all
             difavour
             the
             thing
             to
             be
             made
             out
             by
             our
             Experiment
             ,
             since
             by
             no
             Pumping
             we
             could
             raise
             the
             Water
             quite
             so
             high
             (
             though
             I
             confess
             it
             wanted
             but
             very
             little
             )
             as
             the
             weight
             of
             the
             Atmosphere
             was
             able
             to
             keep
             up
             a
             Cylinder
             of
             Mercury
             proportionable
             to
             it
             in
             height
             ,
             and
             equivalent
             in
             weight
             :
             and
             yet
             I
             presume
             ,
             Your
             Lordship
             will
             easily
             grant
             ,
             that
             there
             was
             at
             least
             as
             much
             care
             used
             in
             this
             Experiment
             ,
             to
             keep
             the
             things
             imploy'd
             about
             it
             tight
             ,
             as
             has
             been
             wont
             to
             be
             used
             by
             Tradesmen
             in
             their
             Pumps
             ,
             where
             t
             is
             not
             so
             easie
             either
             to
             prevent
             a
             little
             insinuation
             of
             the
             Air
             ,
             or
             to
             discern
             it
             .
          
           
             T
             is
             not
             that
             I
             am
             sure
             ,
             that
             even
             all
             our
             care
             would
             have
             kept
             the
             water
             for
             any
             long
             time
             at
             its
             full
             height
             ;
             but
             ,
             that
             the
             Air
             was
             sufficiently
             exhausted
             for
             our
             purpose
             ,
             when
             we
             determin'd
             the
             height
             of
             the
             water
             ,
             I
             was
             induc'd
             to
             conclude
             by
             these
             Circumstances
             .
          
           
             1.
             
             As
             well
             the
             construction
             of
             the
             Engine
             ,
             as
             the
             many
             (
             formerly
             related
             )
             Experiments
             ,
             that
             have
             been
             successfully
             tryed
             with
             it
             ,
             shew
             that
             t
             is
             not
             like
             it
             should
             be
             inferiour
             in
             closeness
             to
             the
             great
             Water-Pumps
             ,
             made
             by
             ordinary
             Tradesmen
             :
             and
             particularly
             
             the
             XI
             .
             Experiment
             foregoing
             ,
             manifests
             ,
             that
             by
             this
             Pump
             Quick-silver
             was
             rais'd
             to
             as
             great
             a
             height
             ,
             as
             the
             Atmosphere
             is
             able
             to
             support
             in
             the
             Torricellian
             Experiment
             .
          
           
             2.
             
             The
             stanchness
             of
             the
             Pipe
             appear'd
             by
             the
             Diminution
             (
             as
             to
             number
             )
             of
             Bubbles
             ,
             that
             appear'd
             at
             the
             top
             of
             the
             Water
             ,
             and
             by
             their
             size
             too
             ,
             for
             when
             there
             was
             a
             leak
             ,
             (
             though
             but
             so
             very
             small
             ,
             that
             the
             water
             could
             not
             get
             out
             at
             it
             in
             the
             Tube
             ,
             )
             it
             might
             usually
             be
             taken
             notice
             of
             by
             the
             attentive
             ear
             of
             him
             that
             stood
             to
             watch
             upon
             the
             Ladder
             ,
             erected
             by
             the
             side
             of
             the
             Tube
             ;
             and
             the
             Air
             that
             got
             in
             ,
             did
             easily
             discover
             it self
             to
             the
             Eye
             by
             large
             Bubbles
             ,
             manifestly
             differing
             from
             those
             that
             came
             from
             the
             Aerial
             particles
             belonging
             to
             the
             water
             ;
             and
             if
             the
             leak
             were
             not
             so
             very
             small
             ,
             the
             Air
             that
             got
             in
             would
             suddenly
             lift
             up
             the
             water
             above
             it
             ,
             and
             perhaps
             fill
             with
             it
             the
             descending
             Pipe.
             
          
           
             3.
             
             Though
             there
             had
             been
             some
             imperceptible
             Leak
             ,
             yet
             that
             would
             not
             have
             hindred
             the
             success
             of
             the
             Experiment
             for
             the
             main
             .
             For
             in
             leaks
             that
             have
             been
             but
             small
             ,
             though
             manifest
             enough
             ,
             we
             have
             often
             ,
             by
             causing
             the
             Pump
             to
             be
             ply'd
             less
             nimbly
             then
             it
             now
             was
             ,
             been
             able
             to
             prosecute
             our
             Tryals
             ;
             because
             the
             Pump
             carried
             of
             still
             more
             Air
             than
             could
             get
             in
             at
             a
             leak
             that
             was
             no
             greater
             .
          
           
             4.
             
             And
             that
             litle
             or
             no
             (
             intruding
             )
             Air
             was
             left
             in
             the
             upper
             part
             of
             our
             Tube
             ,
             was
             evident
             by
             those
             marks
             ,
             whereby
             it
             was
             easie
             for
             them
             that
             are
             well
             acquainted
             with
             the
             Pump
             ,
             to
             estimate
             what
             Air
             is
             left
             in
             the
             vessel
             it
             should
             exhaust
             ,
             and
             particularly
             towards
             the
             end
             of
             our
             operation
             I
             observ'd
             ,
             that
             when
             the
             Sucker
             was
             deprest
             ,
             there
             came
             out
             of
             the
             Water
             that
             cover'd
             the
             Pump
             ,
             so
             very
             few
             bubbles
             ,
             that
             they
             might
             be
             imputed
             to
             the
             Air
             afforded
             by
             the
             Bubbles
             ,
             springing
             from
             the
             water
             in
             the
             Tube
             ;
             whereas
             if
             any
             adventious
             Air
             had
             got
             into
             that
             Cylinder
             of
             water
             ,
             it
             would
             have
             appear'd
             in
             the
             water
             that
             cover'd
             the
             Pump
             .
          
           
             5.
             
             Lastly
             ,
             it
             were
             very
             strange
             ,
             that
             if
             the
             water
             was
             but
             casually
             
             hindred
             by
             some
             Leak
             from
             ascending
             any
             higher
             ,
             it
             should
             be
             so
             easy
             to
             raise
             it
             to
             the
             very
             number
             of
             feet
             that
             our
             Hypothesis
             requires
             ,
             and
             yet
             we
             should
             be
             unable
             by
             obstinate
             Pumping
             to
             raise
             it
             one
             foot
             higher
             .
          
           
             Note
             ,
             1.
             as
             soon
             as
             we
             had
             made
             our
             Experiment
             ,
             and
             thereby
             found
             ,
             that
             what
             was
             requisite
             to
             it
             was
             in
             order
             ;
             I
             sent
             to
             give
             notice
             of
             it
             to
             D
             r
             Wallis
             ,
             and
             D
             r
             Wren
             ,
             as
             Persons
             whose
             curiosity
             makes
             them
             as
             well
             delighted
             with
             such
             Tryals
             ,
             as
             their
             deep
             knowledg
             makes
             Them
             most
             competent
             Judges
             of
             them
             .
             But
             before
             They
             could
             be
             found
             ,
             and
             come
             ,
             it
             being
             grown
             somewhat
             late
             and
             windy
             ,
             I
             that
             was
             not
             very
             well
             ,
             and
             had
             tired
             my self
             with
             going
             up
             and
             down
             ,
             could
             not
             stay
             with
             them
             so
             long
             as
             I
             intended
             ,
             but
             leaving
             the
             rest
             of
             the
             Repeated
             Experiment
             to
             be
             shewn
             them
             by
             
               I.
               M.
            
             (
             who
             had
             been
             very
             industrious
             in
             fitting
             and
             erecting
             the
             Tube
             )
             they
             and
             their
             Learned
             friend
             (
             whom
             they
             brought
             with
             them
             )
             Doctor
             Millington
             ,
             told
             me
             a
             while
             after
             ,
             that
             they
             also
             had
             found
             the
             greatest
             height
             ,
             to
             which
             they
             could
             raise
             the
             water
             ,
             to
             be
             33
             foot
             and
             an
             half
             .
          
           
             2.
             
             When
             the
             Water
             began
             first
             to
             appear
             in
             the
             Glass
             ,
             the
             Bubbles
             would
             be
             ,
             as
             I
             had
             foretold
             ,
             exceeding
             numerous
             ;
             so
             as
             to
             make
             a
             froath
             of
             near
             a
             foot
             high
             ,
             if
             the
             water
             were
             newly
             brought
             ,
             and
             had
             never
             been
             rais'd
             in
             the
             Tube
             before
             .
             But
             if
             the
             Pumping
             were
             long
             continued
             ,
             the
             number
             and
             height
             (
             or
             at
             least
             one
             of
             the
             two
             )
             of
             the
             Aggregate
             of
             Bubbles
             ,
             would
             (
             as
             there
             remain'd
             fewer
             and
             fewer
             Aerial
             particles
             in
             the
             water
             )
             be
             lesser
             and
             lesser
             ;
             but
             their
             emerging
             did
             never
             that
             I
             remember
             wholly
             cease
             .
          
           
             3.
             
             At
             the
             beginning
             also
             there
             would
             appear
             great
             vibrations
             of
             the
             water
             in
             the
             upper
             part
             of
             the
             Tube
             ;
             the
             rising
             and
             the
             falling
             amounting
             sometimes
             to
             a
             foot
             ,
             or
             near
             half
             a
             yard
             :
             but
             these
             grew
             lesser
             and
             lesser
             ,
             as
             those
             of
             the
             Quicksilver
             in
             the
             Torricellian
             Experiment
             use
             to
             do
             .
          
           
             4.
             
             One
             may
             use
             an
             ordinary
             Pail
             to
             hold
             the
             stagnant
             water
             ;
             but
             we
             rather
             imploy'd
             a
             vessel
             of
             Earth
             made
             (
             for
             another
             purpose
             )
             
             somewhat
             slender
             ,
             and
             of
             a
             Cylindrical
             shape
             ,
             because
             in
             a
             narrow
             vessel
             t
             is
             more
             easie
             to
             guess
             by
             the
             rising
             and
             falling
             of
             the
             Liquor
             ,
             how
             the
             Pump
             is
             ply'd
             ,
             and
             to
             perceive
             even
             smaller
             Leaks
             .
          
           
             5.
             
             I
             must
             not
             forget
             to
             take
             notice
             ,
             that
             though
             the
             newly
             nam'd
             Gentlemen
             came
             to
             me
             (
             when
             they
             had
             seen
             the
             Experiment
             tryed
             )
             within
             less
             than
             an
             hour
             after
             the
             time
             I
             had
             look'd
             upon
             the
             Baroscope
             ,
             and
             observ'd
             the
             Quick-silver
             to
             stand
             somewhat
             beneath
             29
             inches
             ,
             and
             3
             eights
             ;
             yet
             when
             presently
             upon
             their
             return
             I
             consulted
             the
             same
             instrument
             again
             ,
             the
             Mercury
             appear'd
             to
             be
             sensibly
             risen
             ,
             being
             somewhat
             (
             though
             but
             very
             litle
             )
             above
             9
             and
             20
             inches
             ,
             and
             3
             eights
             ,
             and
             5
             or
             6
             hours
             after
             (
             at
             bed-time
             )
             I
             found
             it
             to
             be
             yet
             more
             considerably
             risen
             .
             Which
             may
             keep
             Your
             Lordship
             from
             wondring
             at
             what
             I
             intimated
             a
             little
             above
             ,
             touching
             Monsieur
             Paschal's
             Experiment
             ,
             as
             well
             as
             touching
             the
             disappointment
             of
             the
             Pump-makers
             endeavours
             .
             For
             t
             is
             not
             onely
             possible
             ,
             that
             (
             as
             I
             have
             elsewhere
             noted
             )
             Water
             may
             be
             raised
             in
             the
             same
             Pump
             (
             though
             we
             suppose
             it
             still
             equally
             stanch
             )
             higher
             at
             one
             time
             than
             at
             another
             :
             but
             't
             was
             contingent
             ,
             that
             ,
             in
             Monsieur
             Paschal's
             noble
             attempt
             to
             imitate
             the
             Torricellian
             Experiment
             with
             Water
             in
             stead
             of
             Quick-silver
             ,
             the
             proportion
             betwixt
             the
             heights
             of
             those
             two
             Liquors
             in
             their
             respective
             Tubes
             answer'd
             so
             well
             to
             their
             specifick
             Gravities
             .
             For
             ,
             the
             varying
             weight
             of
             the
             Atmosphere
             being
             not
             then
             (
             that
             appears
             )
             known
             ,
             or
             consequently
             taken
             into
             consideration
             ;
             if
             Monsieur
             Paschal
             ,
             having
             tryed
             the
             Torricellian
             Experiment
             ,
             when
             the
             Air
             was
             for
             instance
             very
             heavy
             ,
             had
             tryed
             his
             own
             Experiment
             ,
             when
             the
             Atmosphere
             had
             been
             as
             light
             as
             I
             have
             often
             enough
             observ'd
             it
             to
             be
             ,
             he
             might
             have
             found
             his
             Cylinder
             of
             Water
             to
             have
             been
             half
             a
             Yard
             or
             two
             foot
             shorter
             than
             the
             formerly
             measur'd
             height
             of
             the
             Quick-silver
             would
             have
             required
             .
          
           
             I
             have
             now
             no
             more
             to
             adde
             about
             this
             15
             th
             Experiment
             ,
             but
             that
             it
             may
             serve
             for
             a
             sufficient
             confirmation
             of
             what
             I
             note
             in
             another
             
             Treatise
             ,
             against
             those
             Hydraulical
             &
             Pneumatical
             Writers
             ,
             who
             pretend
             to
             teach
             wayes
             of
             making
             Water
             pass
             by
             inflected
             Pipes
             ,
             and
             by
             the
             help
             of
             Suction
             ,
             from
             one
             side
             of
             a
             Mountain
             to
             the
             other
             ,
             be
             the
             Mountain
             never
             so
             high
             .
             For
             ,
             if
             the
             Water
             be
             to
             ascend
             as
             't
             were
             spontaneously
             above
             35
             or
             36
             foot
             ,
             a
             Sucking
             Pump
             will
             not
             ordinarily
             ,
             at
             least
             here
             in
             England
             ,
             be
             able
             to
             raise
             it
             .
          
           
             And
             now
             I
             speak
             of
             Mountains
             ,
             it
             will
             not
             be
             altogether
             impertinent
             to
             add
             ,
             that
             if
             it
             had
             not
             been
             for
             unseasonable
             weather
             ,
             I
             had
             thought
             fit
             to
             make
             the
             foregoing
             11
             th
             Experiment
             (
             of
             elevating
             Mercury
             by
             Suction
             )
             to
             be
             tryed
             at
             the
             top
             of
             an
             Hill
             ,
             not
             far
             from
             the
             place
             I
             then
             was
             at
             .
             For
             by
             what
             has
             been
             already
             delivered
             ,
             it
             appears
             ,
             that
             we
             might
             have
             estimated
             the
             height
             ,
             to
             which
             the
             Water
             may
             be
             there
             elevated
             by
             Suction
             ,
             without
             repeating
             the
             Experiment
             with
             a
             thirty
             five
             foot
             Tube
             ,
             (
             which
             we
             could
             not
             hope
             for
             conveniency
             to
             do
             ,
             )
             by
             the
             utmost
             height
             to
             which
             our
             Engine
             could
             have
             rais'd
             Mercury
             :
             and
             it
             may
             be
             of
             some
             use
             to
             be
             able
             from
             Experiments
             to
             make
             some
             estimate
             (
             for
             it
             can
             scarce
             be
             an
             accurate
             one
             )
             how
             much
             it
             may
             be
             expected
             ,
             that
             Pumps
             shall
             (
             
               caeteris
               paribus
            
             )
             loose
             of
             their
             power
             of
             elevating
             Water
             by
             Suction
             ,
             by
             being
             imploy'd
             at
             the
             top
             of
             an
             Hill
             ,
             in
             stead
             of
             being
             so
             at
             the
             bottom
             ,
             or
             on
             a
             Plain
             .
             Remembring
             always
             what
             I
             lately
             intimated
             ,
             that
             even
             in
             the
             same
             place
             Liquors
             will
             be
             brought
             to
             ascend
             by
             Suction
             to
             a
             greater
             or
             less
             height
             at
             one
             time
             than
             another
             ,
             according
             to
             the
             varying
             Gravity
             of
             the
             Atmosphere
             .
          
        
         
           
             EXPERIMENT
             XVI
             .
          
           
             About
             the
             bending
             of
             a
             Springy
             Body
             in
             the
             Exhausted
             Receiver
             .
          
           
             THe
             cause
             of
             the
             Motion
             of
             Restitution
             in
             Bodies
             ,
             and
             consequently
             of
             that
             which
             makes
             some
             of
             them
             Springy
             ,
             which
             
             far
             the
             greater
             part
             of
             them
             are
             not
             ,
             has
             been
             ingeniously
             attempted
             by
             some
             Modern
             Corpuscularians
             ,
             and
             especially
             Cartesians
             ;
             but
             since
             divers
             Learned
             and
             Judicious
             men
             do
             still
             look
             upon
             the
             cause
             of
             Elasticity
             ,
             as
             a
             thing
             that
             needs
             to
             be
             yet
             farther
             enquired
             into
             ;
             and
             because
             I
             am
             not
             my self
             so
             well
             satisfied
             as
             to
             blame
             their
             Curiosity
             ,
             I
             held
             it
             not
             unfit
             to
             examine
             by
             the
             help
             of
             our
             Engine
             their
             Conjecture
             ,
             who
             imagine
             that
             the
             Air
             may
             have
             a
             great
             stroak
             in
             the
             making
             of
             bodies
             Springy
             ;
             and
             this
             I
             the
             rather
             did
             ,
             because
             I
             had
             *
             elswhere
             shewn
             ,
             that
             there
             is
             no
             need
             to
             assert
             ,
             that
             in
             all
             Bodies
             ,
             that
             have
             it
             ,
             the
             Elastical
             power
             flows
             immediately
             from
             the
             Form
             ,
             but
             that
             in
             divers
             of
             them
             it
             depends
             upon
             the
             Mechanicanical
             structure
             of
             the
             Body
             .
          
           
             To
             make
             some
             Tryal
             therefore
             ,
             whether
             the
             Air
             have
             any
             great
             Interest
             in
             the
             Motion
             of
             Restitution
             ,
             we
             took
             a
             piece
             of
             Whalebone
             of
             a
             convenient
             bigness
             and
             length
             ,
             and
             having
             fasten'd
             one
             end
             of
             it
             in
             a
             hole
             made
             in
             a
             thick
             and
             heavy
             Trencher
             ,
             to
             be
             placed
             on
             the
             Plate
             of
             the
             Engine
             ,
             we
             tyed
             to
             the
             other
             end
             a
             Weight
             ,
             whereby
             the
             Whalebone
             was
             moderately
             bent
             ,
             the
             weight
             reaching
             down
             so
             near
             to
             a
             Body
             plac'd
             in
             a
             level
             position
             under
             it
             ,
             that
             if
             the
             Spring
             were
             but
             a
             little
             weaken'd
             ,
             the
             weight
             must
             either
             lean
             upon
             ,
             or
             at
             least
             touch
             the
             Horizontal
             plain
             :
             or
             if
             on
             the
             other
             side
             the
             Spring
             should
             grow
             sensibly
             stronger
             ,
             it
             might
             be
             easily
             perceiv'd
             by
             the
             distance
             of
             the
             weight
             ,
             which
             was
             so
             near
             the
             plain
             ,
             that
             a
             litle
             increase
             of
             it
             must
             be
             visible
             .
          
           
             This
             done
             ,
             we
             convey'd
             these
             things
             into
             the
             Receiver
             ,
             and
             order'd
             those
             that
             pump'd
             to
             shake
             it
             as
             litle
             as
             they
             could
             ,
             that
             the
             weight
             might
             not
             knock
             against
             the
             Body
             that
             lay
             under
             it
             ,
             or
             so
             shake
             it
             ,
             as
             to
             hinder
             us
             from
             discerning
             whether
             or
             no
             it
             were
             depress'd
             by
             the
             bare
             withdrawing
             of
             the
             Air.
             
          
           
             And
             when
             the
             Air
             had
             been
             well
             pump'd
             out
             ,
             I
             watcht
             attentively
             whether
             any
             notable
             Change
             in
             the
             distance
             of
             the
             weight
             from
             the
             almost
             contiguous
             plain
             would
             be
             produc'd
             upon
             its
             being
             let
             in
             again
             :
             for
             the
             weight
             was
             then
             at
             rest
             ,
             and
             the
             returning
             
             Air
             flowing
             in
             much
             more
             speedily
             than
             it
             could
             before
             be
             drawn
             out
             ,
             I
             thought
             this
             the
             likeliest
             time
             to
             discover
             whether
             the
             absence
             of
             the
             Air
             had
             sensibly
             altered
             the
             Spring
             of
             the
             Whalebone
             .
             But
             though
             the
             Experiment
             were
             made
             more
             than
             once
             ,
             I
             could
             satisfie
             my self
             onely
             in
             this
             ,
             that
             the
             depression
             or
             elevation
             of
             the
             Weight
             ,
             that
             was
             due
             to
             the
             true
             and
             meer
             change
             of
             the
             Spring
             ,
             was
             not
             very
             considerable
             ,
             since
             I
             did
             not
             think
             my self
             sure
             ,
             that
             I
             perceiv'd
             any
             at
             all
             :
             for
             though
             it
             be
             true
             ,
             that
             sometimes
             ,
             when
             the
             Receiver
             was
             well
             exhausted
             ,
             the
             Weight
             seem'd
             to
             be
             a
             little
             deprest
             ,
             yet
             That
             I
             thought
             was
             very
             litle
             ,
             if
             any
             thing
             more
             than
             what
             might
             be
             ascrib'd
             to
             the
             absence
             of
             the
             Air
             ,
             not
             consider'd
             as
             a
             Body
             that
             had
             any
             thing
             to
             do
             directly
             with
             the
             Spring
             ,
             but
             as
             a
             Body
             that
             had
             some
             (
             though
             but
             a
             litle
             )
             Weight
             ;
             upon
             which
             account
             it
             made
             the
             medium
             ,
             wherein
             the
             Experiment
             was
             tried
             ,
             contribute
             to
             support
             the
             Weight
             that
             bent
             the
             Spring
             ;
             which
             Weight
             ,
             when
             the
             Air
             was
             absent
             ,
             must
             (
             being
             now
             in
             a
             lighter
             medium
             )
             have
             its
             Gravitation
             increas'd
             by
             as
             much
             weight
             ,
             as
             a
             quantity
             of
             the
             exhausted
             Air
             ,
             equal
             to
             it
             in
             bulk
             ,
             could
             amount
             to
             .
             But
             this
             Experiment
             being
             tried
             only
             with
             VVhalebone
             ,
             and
             in
             a
             Receiver
             not
             very
             Great
             ,
             may
             deserve
             to
             be
             further
             tryed
             in
             taller
             Glasses
             ,
             with
             Springs
             of
             other
             kinds
             ,
             and
             by
             the
             motions
             of
             a
             VVatch
             ,
             and
             other
             more
             artificial
             Contrivances
             .
          
        
         
           
             EXPERIMENT
             XVII
             .
          
           
             About
             the
             making
             of
             Mercurial
             ,
             and
             other
             Gages
             ,
             whereby
             to
             estimate
             how
             the
             Receiver
             is
             exhausted
             .
          
           
             BEcause
             the
             Air
             being
             invisible
             ,
             it
             is
             not
             always
             easie
             to
             know
             whether
             it
             be
             sufficiently
             pump'd
             out
             of
             the
             Receiver
             that
             was
             to
             be
             exhausted
             ;
             we
             thought
             it
             would
             be
             very
             convenient
             to
             have
             some
             Instrument
             within
             the
             Receiver
             ,
             that
             might
             serve
             
             for
             a
             Gage
             ,
             or
             Standard
             ;
             whereby
             to
             judge
             whether
             or
             not
             it
             were
             sufficiently
             exhausted
             .
          
           
             To
             this
             purpose
             divers
             Expedients
             were
             thought
             on
             ,
             and
             some
             of
             them
             put
             in
             practise
             ;
             which
             ,
             though
             not
             equally
             commodious
             ,
             may
             yet
             all
             of
             them
             be
             usefully
             imploy'd
             ,
             one
             on
             this
             occasion
             ,
             and
             another
             on
             that
             .
          
           
             The
             First
             (
             if
             I
             misremember
             not
             )
             that
             I
             propos'd
             ,
             was
             a
             Bladder
             ,
             (
             which
             may
             be
             greater
             or
             less
             ,
             according
             to
             the
             Size
             of
             the
             Vessel
             it
             is
             to
             serve
             for
             )
             to
             be
             very
             strongly
             tied
             at
             the
             neck
             ,
             after
             having
             had
             onely
             so
             much
             Air
             left
             in
             the
             folds
             of
             it
             ,
             as
             may
             serve
             to
             blow
             up
             the
             Bladder
             to
             its
             full
             dimensions
             ,
             when
             the
             Receiver
             is
             very
             well
             exhausted
             ,
             and
             not
             before
             .
             But
             though
             Your
             Lord-ship
             will
             hereafter
             find
             that
             I
             yet
             make
             use
             of
             small
             Bladders
             on
             certain
             occasions
             ,
             in
             which
             they
             are
             peculiarly
             convenient
             ,
             yet
             in
             many
             cases
             they
             do
             ,
             when
             the
             Glasses
             are
             well
             exhausted
             ,
             take
             up
             too
             much
             room
             in
             them
             ,
             and
             hinder
             the
             Objects
             ,
             included
             in
             the
             Receiver
             ,
             from
             being
             observ'd
             from
             all
             the
             sides
             of
             it
             .
          
           
             Another
             sort
             of
             Gage
             was
             made
             with
             Quick-silver
             ,
             pour'd
             into
             a
             very
             short
             Pipe
             ,
             which
             was
             afterwards
             inverted
             into
             a
             litle
             Glass
             of
             stagnant
             Quick-silver
             ,
             according
             to
             the
             manner
             of
             the
             Torricellian
             Experiment
             .
             For
             this
             Pipe
             being
             but
             a
             very
             few
             inches
             long
             ,
             the
             Mercury
             in
             it
             would
             not
             begin
             to
             descend
             ,
             till
             a
             very
             Great
             proportion
             of
             Air
             was
             pump'd
             out
             of
             the
             Receiver
             ;
             because
             till
             then
             ,
             the
             Spring
             of
             the
             remaining
             Air
             would
             be
             strong
             enough
             to
             be
             able
             to
             keep
             up
             so
             short
             a
             Cylinder
             of
             Mercury
             .
             And
             this
             kind
             of
             Gage
             is
             no
             bad
             one
             .
             But
             because
             ,
             to
             omit
             some
             other
             litle
             inconveniences
             ,
             it
             cannot
             easily
             be
             suspended
             ,
             (
             which
             in
             divers
             Experiments
             't
             is
             fit
             the
             Gage
             should
             be
             ,
             )
             and
             the
             Mercury
             in
             it
             is
             apt
             to
             be
             too
             much
             shaken
             by
             the
             motion
             of
             the
             Engine
             ,
             there
             was
             another
             kind
             of
             Gage
             by
             some
             Ingenious
             man
             (
             who
             ever
             he
             were
             )
             substituted
             in
             its
             place
             ,
             consisting
             of
             a
             kind
             of
             Siphon
             ,
             whose
             shorter
             leg
             hath
             belonging
             to
             it
             a
             large
             Bubble
             of
             Glass
             ,
             most
             commonly
             made
             use
             of
             at
             an
             Illustrious
             meeting
             of
             Virtuosi
             ;
             where
             Your
             Lordship
             having
             seen
             it
             ,
             I
             shall
             not
             need
             to
             describe
             it
             more
             particularly
             .
          
           
           
             But
             none
             of
             the
             Gages
             I
             had
             formerly
             us'd
             ,
             nor
             even
             this
             last
             ,
             having
             the
             conveniences
             that
             some
             of
             my
             Experiments
             require
             ;
             I
             was
             fain
             to
             devise
             another
             ,
             which
             is
             That
             I
             most
             make
             use
             of
             ,
             as
             having
             advantages
             ,
             some
             or
             other
             of
             which
             each
             of
             the
             Gages
             already
             mentioned
             wants
             ;
             for
             even
             that
             with
             Spirit
             of
             Wine
             ,
             not
             to
             mention
             lesser
             disadvantages
             ,
             hath
             a
             Bubble
             too
             Great
             to
             let
             it
             be
             useful
             in
             vessels
             so
             slender
             ,
             as
             for
             some
             purposes
             I
             divers
             times
             imploy
             ;
             and
             this
             short
             Cylinder
             of
             so
             light
             a
             Liquor
             as
             spirit
             of
             Wine
             ,
             makes
             the
             subsidence
             of
             the
             Liquor
             be
             indeed
             a
             good
             sign
             that
             the
             Receiver
             is
             well
             exhausted
             ,
             but
             gives
             us
             not
             an
             account
             what
             Quantity
             of
             Air
             may
             be
             in
             the
             Receiver
             ,
             'till
             it
             be
             arriv'd
             at
             that
             great
             measure
             of
             Rarefaction
             ;
             and
             the
             same
             Liquor
             ,
             being
             upon
             a
             very
             small
             leak
             (
             such
             as
             would
             not
             be
             prejudicial
             to
             many
             Experiments
             )
             impell'd
             up
             to
             the
             top
             of
             the
             Gage
             ,
             we
             cannot
             afterwards
             by
             this
             Instrument
             take
             any
             measure
             of
             the
             Air
             that
             gets
             in
             at
             the
             Leak
             .
             But
             now
             there
             are
             divers
             Experiments
             where
             I
             desire
             to
             see
             the
             Phaenomena
             that
             will
             happen
             ,
             not
             onely
             (
             or
             perhaps
             not
             at
             all
             )
             upon
             the
             uttermost
             Exhaustion
             of
             the
             Air
             ,
             but
             when
             the
             Pressure
             of
             it
             is
             withdrawn
             to
             such
             or
             such
             a
             measure
             ,
             and
             also
             when
             the
             Air
             is
             gradually
             readmitted
             .
          
           
             To
             make
             the
             Gage
             we
             are
             speaking
             of
             ,
             take
             a
             very
             slender
             and
             Cylindrical
             Pipe
             of
             Glass
             ,
             of
             6
             ,
             8
             ,
             10
             ,
             or
             more
             Inches
             in
             length
             ,
             and
             not
             so
             big
             as
             a
             Goose-quill
             ,
             
             (
             but
             such
             as
             we
             imploy
             for
             the
             Stems
             of
             seal'd
             Weather
             Glasses
             ,
             )
             and
             having
             at
             the
             flame
             of
             a
             Lamp
             melted
             it
             ,
             but
             not
             too
             near
             the
             middle
             ,
             to
             make
             of
             it
             by
             bending
             it
             a
             Siphon
             ,
             whose
             two
             Legs
             are
             to
             be
             not
             onely
             parallel
             to
             one
             another
             ,
             but
             as
             litle
             distant
             any
             where
             from
             one
             another
             as
             conveniently
             may
             be
             .
             In
             one
             (
             which
             is
             usually
             the
             longer
             )
             of
             these
             Legs
             ,
             there
             is
             to
             be
             left
             at
             the
             top
             ,
             either
             half
             an
             inch
             ,
             or
             a
             whole
             inch
             ,
             or
             more
             or
             less
             than
             either
             ,
             (
             according
             to
             the
             length
             of
             the
             Gage
             ,
             or
             the
             scope
             of
             the
             Experimenter
             )
             of
             Air
             in
             its
             natural
             state
             ,
             neither
             rarefied
             ,
             nor
             condens'd
             ;
             the
             rest
             of
             the
             longer
             leg
             ,
             and
             as
             great
             a
             part
             of
             the
             shorter
             as
             shall
             be
             thought
             fit
             ,
             being
             to
             be
             fill'd
             with
             Quick-silver
             .
             This
             done
             ,
             there
             may
             be
             Marks
             
             plac'd
             at
             the
             outside
             of
             the
             longer
             (
             or
             sealed
             )
             leg
             ,
             whereby
             to
             measure
             the
             Expansion
             of
             the
             Air
             included
             in
             the
             same
             leg
             ,
             and
             these
             marks
             may
             be
             either
             litle
             Glass
             Knubs
             ,
             about
             the
             bigness
             of
             Pins
             heads
             ,
             fasten'd
             by
             the
             help
             of
             a
             Lamp
             at
             certain
             distances
             to
             the
             longer
             leg
             of
             the
             Siphon
             ,
             or
             else
             the
             divisions
             of
             an
             Inch
             made
             on
             a
             list
             of
             Paper
             ,
             and
             pasted
             on
             either
             to
             the
             Siphon
             it self
             ,
             or
             to
             the
             slender
             Frame
             ,
             which
             on
             some
             occasions
             we
             fasten
             the
             Gage
             to
             .
          
           
             This
             Instrument
             being
             convey'd
             into
             a
             Receiver
             ,
             (
             which
             for
             expedition
             sake
             we
             choose
             as
             small
             as
             will
             serve
             the
             turn
             ,
             )
             the
             Air
             is
             to
             be
             very
             diligently
             pump'd
             out
             ,
             and
             then
             notice
             is
             to
             be
             taken
             to
             what
             part
             of
             the
             Gage
             the
             Mercury
             is
             deprest
             ,
             that
             we
             may
             know
             ,
             when
             we
             shall
             afterwards
             see
             the
             Mercury
             driven
             so
             far
             ,
             that
             the
             Receiver
             ,
             the
             Gage
             is
             plac'd
             in
             ,
             is
             well
             exhausted
             .
             And
             if
             it
             be
             much
             desired
             to
             know
             more
             accurately
             (
             for
             one
             may
             arrive
             pretty
             near
             the
             truth
             by
             Guess
             )
             what
             stations
             of
             the
             Mercury
             in
             the
             Gage
             are
             answerable
             to
             the
             degrees
             of
             the
             Rarefaction
             of
             the
             Air
             in
             the
             Receiver
             ;
             that
             may
             be
             compassed
             either
             by
             Calculation
             ,
             (
             which
             is
             not
             so
             easie
             ,
             and
             supposes
             some
             Hypotheses
             ,
             )
             or
             (
             though
             not
             without
             some
             trouble
             )
             by
             letting
             in
             the
             water
             as
             often
             as
             is
             necessary
             ,
             into
             a
             Receiver
             ,
             whose
             intire
             capacity
             is
             first
             measured
             ,
             and
             in
             which
             there
             may
             be
             Marks
             made
             to
             shew
             when
             the
             water
             to
             be
             let
             in
             shall
             fill
             a
             fourth
             part
             ,
             or
             half
             ,
             or
             three
             quarters
             &c.
             of
             the
             Cavity
             .
             For
             if
             (
             for
             instance
             )
             when
             the
             Quick-silver
             in
             the
             Gage
             is
             deprest
             to
             such
             a
             Mark
             ,
             you
             let
             in
             the
             water
             ,
             and
             that
             Liquor
             appears
             to
             fill
             a
             fourth
             part
             of
             the
             Receiver
             ,
             you
             may
             conclude
             ,
             that
             about
             a
             4
             th
             part
             of
             the
             Air
             was
             pump'd
             out
             ,
             or
             that
             a
             4
             th
             part
             of
             the
             Spring
             ,
             that
             the
             whole
             included
             Air
             had
             ,
             was
             lost
             by
             the
             Exhaustion
             ,
             when
             the
             Quick
             silver
             in
             the
             Gage
             was
             at
             the
             Mark
             above
             mentioned
             ;
             &
             if
             the
             admitted
             water
             do
             considerably
             either
             fall
             short
             of
             ,
             or
             exceed
             the
             quantity
             you
             expected
             ,
             you
             may
             the
             next
             time
             let
             in
             the
             water
             either
             after
             the
             Mercury
             has
             a
             litle
             past
             the
             former
             Mark
             ,
             or
             a
             litle
             before
             it
             is
             arriv'd
             at
             it
             .
             And
             when
             once
             you
             have
             this
             way
             obtain'd
             one
             pretty
             
             long
             and
             accurate
             Gage
             ,
             you
             will
             not
             need
             to
             take
             so
             much
             pains
             to
             make
             others
             ,
             since
             you
             may
             divide
             them
             by
             the
             help
             of
             that
             one
             ;
             for
             this
             being
             plac'd
             with
             any
             other
             in
             a
             small
             Receiver
             ,
             when
             the
             Mercury
             in
             the
             Standard-Gage
             (
             if
             I
             may
             so
             call
             it
             )
             is
             deprest
             to
             any
             of
             the
             determinate
             divisions
             obtain'd
             by
             observation
             ,
             you
             may
             thence
             conclude
             how
             much
             the
             Air
             in
             the
             Receiver
             is
             rarefied
             ,
             and
             consequently
             by
             taking
             notice
             of
             the
             place
             where
             the
             Mercury
             rests
             in
             the
             other
             Gage
             ,
             you
             may
             determine
             what
             degree
             of
             Exhaustion
             in
             a
             Receiver
             is
             denoted
             by
             that
             station
             of
             the
             Mercury
             in
             this
             Gage
             .
          
           
             Perhaps
             I
             need
             not
             tell
             your
             Lordship
             that
             the
             Ground
             of
             this
             contrivance
             was
             ,
             that
             whereas
             in
             divers
             other
             Gages
             ,
             when
             the
             Pump
             came
             to
             be
             obstinately
             ply'd
             ,
             the
             Expansion
             of
             the
             included
             Air
             would
             be
             so
             great
             ,
             that
             it
             would
             either
             drive
             out
             the
             Liquor
             ,
             especially
             if
             it
             were
             light
             ,
             or
             in
             part
             make
             an
             escape
             through
             it
             :
             I
             judg'd
             that
             in
             such
             an
             Instrument
             ,
             as
             that
             newly
             describ'd
             ,
             those
             inconveniences
             would
             be
             avoided
             ,
             because
             that
             the
             more
             the
             Air
             should
             come
             to
             be
             dilated
             ,
             the
             greater
             weight
             of
             Quick-silver
             it
             would
             in
             the
             shorter
             Leg
             have
             to
             raise
             ,
             which
             would
             sufficiently
             hinder
             it
             from
             making
             that
             heavy
             liquor
             run
             over
             ;
             and
             the
             same
             ponderousness
             of
             the
             Liquor
             ,
             together
             with
             the
             slenderness
             of
             the
             Pipe
             ,
             would
             likewise
             hinder
             the
             included
             Air
             from
             getting
             through
             in
             Bubbles
             .
          
           
             NB.
             1.
             
             For
             most
             Experiments
             ,
             where
             exact
             measures
             are
             not
             required
             ,
             it
             will
             not
             be
             so
             necessary
             to
             mark
             the
             Gage
             at
             any
             other
             station
             of
             the
             Quick-silver
             then
             that
             which
             t
             is
             brought
             to
             by
             the
             Exhaustion
             of
             the
             Receiver
             ,
             for
             by
             that
             alone
             we
             may
             know
             when
             the
             Air
             is
             well
             pump'd
             out
             of
             the
             Receiver
             ,
             wherein
             the
             Gage
             is
             included
             :
             and
             when
             one
             is
             a
             litle
             us'd
             to
             some
             particular
             Gage
             ,
             one
             may
             by
             the
             subsidence
             of
             the
             Mercury
             guess
             at
             the
             degree
             of
             the
             Airs
             rarefaction
             ,
             so
             near
             as
             may
             serve
             the
             turn
             in
             such
             Experiments
             .
             But
             when
             this
             Instrument
             is
             to
             be
             us'd
             about
             nice
             Tryals
             ,
             where
             it
             may
             be
             thought
             requisite
             to
             have
             it
             divided
             according
             to
             one
             of
             the
             ways
             formerly
             proposed
             ,
             it
             will
             on
             divers
             
             occasions
             be
             more
             secure
             (
             in
             case
             the
             maker
             of
             the
             Gage
             has
             skill
             to
             do
             it
             ,
             )
             to
             put
             to
             the
             Divisions
             rather
             by
             litle
             Knubs
             of
             Glass
             ,
             than
             by
             Paper
             ;
             because
             this
             will
             on
             such
             occasions
             be
             in
             danger
             either
             to
             be
             rubb'd
             off
             ,
             or
             wetted
             .
             And
             if
             Glass-marks
             be
             us'd
             ,
             it
             will
             be
             convenient
             that
             every
             fifth
             ,
             or
             tenth
             ,
             or
             such
             Ordinal
             number
             as
             shall
             be
             judg'd
             fit
             ,
             be
             made
             of
             Glass
             of
             a
             differing
             colour
             ,
             for
             distinction
             sake
             ,
             &
             the
             more
             easie
             reckoning
             .
             We
             sometimes
             for
             a
             need
             apply
             ,
             in
             stead
             of
             these
             Glass-knubs
             ,
             little
             marks
             of
             hard
             sealing
             Wax
             ,
             which
             will
             not
             be
             injur'd
             by
             moisture
             ,
             as
             those
             Papers
             will
             that
             are
             pasted
             on
             ;
             but
             these
             of
             Wax
             ,
             though
             in
             many
             cases
             useful
             ,
             are
             not
             comparable
             to
             the
             other
             in
             all
             ,
             since
             if
             they
             be
             very
             small
             ,
             they
             are
             easily
             rubb'd
             off
             ,
             and
             if
             large
             ,
             they
             make
             not
             the
             Division
             exact
             enough
             ,
             and
             often
             hide
             the
             true
             place
             of
             the
             Quick-silver
             .
          
           
             I
             shall
             here
             about
             the
             Mercurial
             Gages
             add
             onely
             this
             Hint
             ,
             that
             what
             I
             propos'd
             to
             my self
             in
             that
             Contrivance
             ,
             was
             not
             onely
             to
             estimate
             the
             Air
             pump'd
             out
             of
             the
             Receiver
             ,
             or
             that
             remaining
             in
             it
             ;
             but
             also
             ,
             by
             the
             help
             of
             this
             Instrument
             (
             as
             elsewhere
             by
             another
             Experiment
             )
             to
             measure
             (
             somewhat
             near
             )
             the
             strength
             of
             the
             Spring
             of
             rarefied
             Air
             ,
             according
             to
             its
             several
             degrees
             of
             Rarefaction
             ;
             and
             by
             this
             Observation
             ,
             in
             concurrence
             with
             other
             things
             ,
             I
             hoped
             we
             might
             (
             according
             to
             what
             I
             have
             elsewhere
             insinuated
             )
             be
             assisted
             to
             estimate
             ,
             by
             the
             Cylinder
             of
             Mercury
             rais'd
             in
             the
             open
             leg
             ,
             the
             Expansion
             of
             the
             Air
             included
             in
             the
             sealed
             leg
             :
             but
             of
             these
             things
             I
             design'd
             in
             this
             place
             to
             give
             but
             an
             Intimation
             .
          
           
             3.
             
             That
             leg
             of
             the
             Gage
             that
             includes
             the
             Air
             ,
             may
             be
             seal'd
             up
             either
             at
             the
             beginning
             ,
             before
             the
             Pipe
             be
             bent
             into
             a
             Syphon
             ,
             or
             (
             which
             is
             much
             better
             )
             after
             the
             following
             manner
             .
             Before
             you
             bend
             the
             Pipe
             ,
             draw
             out
             the
             end
             of
             it
             ,
             which
             you
             mean
             to
             seal
             ,
             to
             a
             short
             and
             very
             slender
             Thread
             ;
             then
             having
             made
             the
             Pipe
             a
             Siphon
             ,
             pour
             into
             the
             leg
             ,
             which
             is
             to
             remain
             open
             ,
             as
             much
             Quick-silver
             as
             you
             shall
             judg
             convenient
             ,
             which
             will
             rise
             to
             an
             equal
             height
             in
             the
             other
             leg
             ;
             out
             of
             which
             by
             gently
             inclining
             
             the
             Siphon
             ,
             you
             may
             pour
             out
             the
             superfluous
             Mercury
             ,
             (
             if
             there
             be
             any
             ,
             )
             and
             when
             you
             see
             that
             there
             is
             an
             inch
             ,
             or
             half
             an
             inch
             (
             or
             what
             part
             you
             design'd
             to
             leave
             for
             Air
             )
             unfill'd
             with
             Mercury
             ,
             next
             to
             the
             end
             that
             is
             to
             be
             clos'd
             ;
             and
             that
             the
             rest
             of
             that
             leg
             ,
             and
             as
             much
             (
             as
             you
             think
             fit
             )
             of
             the
             other
             is
             full
             of
             Quick-silver
             ,
             you
             may
             ,
             by
             keeping
             the
             Siphon
             in
             the
             same
             posture
             ,
             and
             warily
             applying
             the
             slender
             Apex
             above
             mentioned
             to
             the
             upper
             part
             of
             the
             flame
             of
             a
             Lamp
             ,
             blown
             Horizontal
             ,
             easily
             seal
             up
             that
             Apex
             without
             cracking
             ,
             or
             prejudicing
             the
             open
             leg
             ,
             or
             considerably
             injuring
             the
             Air
             hole
             ,
             that
             was
             to
             be
             seal'd
             up
             in
             the
             other
             .
             And
             this
             sealing
             of
             one
             leg
             must
             (
             as
             t
             is
             evident
             )
             keep
             the
             Mercury
             suspended
             in
             it
             ,
             though
             it
             be
             higher
             by
             divers
             inches
             than
             that
             in
             the
             open
             leg
             ,
             till
             the
             withdrawing
             of
             the
             external
             Air
             enable
             the
             included
             ,
             by
             expanding
             it self
             to
             depress
             the
             Mercury
             in
             the
             seal'd
             leg
             ,
             and
             raise
             it
             in
             the
             open
             .
          
           
             4.
             
             How
             the
             length
             of
             these
             Mercurial
             Gages
             is
             to
             be
             varied
             ,
             according
             to
             the
             Bigness
             and
             Shape
             of
             the
             slender
             Receivers
             they
             are
             to
             be
             imploy'd
             in
             ,
             and
             how
             they
             may
             easily
             be
             made
             either
             to
             stand
             upright
             at
             the
             bottom
             of
             the
             Receiver
             ,
             or
             be
             kept
             hanging
             in
             the
             middle
             ,
             or
             near
             the
             top
             of
             it
             (
             as
             occasion
             may
             require
             ,
             )
             and
             how
             the
             open
             end
             may
             be
             made
             to
             secure
             the
             Mercury
             ,
             in
             cases
             where
             that
             is
             needful
             ,
             belongs
             not
             so
             properly
             to
             this
             Treatise
             ,
             as
             to
             the
             Second
             part
             of
             the
             Continuation
             ;
             where
             ,
             if
             ever
             I
             trouble
             Your
             Lordship
             with
             it
             ,
             the
             Usefulness
             of
             this
             sort
             of
             Gages
             ,
             and
             the
             Circumstances
             that
             may
             advantage
             them
             ,
             will
             best
             appear
             .
          
           
             5.
             
             There
             being
             some
             Experiments
             ,
             wherein
             it
             is
             not
             desir'd
             that
             the
             Receiver
             should
             be
             neer
             exhausted
             ,
             but
             rather
             that
             the
             degrees
             of
             the
             Airs
             rarefaction
             ,
             which
             ought
             not
             to
             be
             very
             great
             ,
             should
             be
             well
             measur'd
             ;
             we
             may
             in
             such
             cases
             make
             use
             of
             Gages
             shap'd
             like
             those
             hitherto
             describ'd
             ,
             but
             made
             as
             long
             as
             the
             Receiver
             will
             well
             admit
             ,
             and
             furnish'd
             in
             stead
             of
             Quick-silver
             either
             with
             spirit
             of
             Wine
             coloured
             with
             Cocheneel
             ,
             
               or
               else
            
             with
             the
             tincture
             of
             red
             Rose-leaves
             ,
             drawn
             onely
             with
             common
             Water
             ,
             
             made
             shap
             by
             a
             litle
             either
             of
             the
             Oyl
             ,
             or
             the
             spirit
             of
             Vitriol
             ,
             or
             of
             common
             Salt.
             For
             the
             lightness
             of
             these
             Liquors
             in
             comparison
             of
             Quick-silver
             will
             allow
             the
             Expansins
             of
             the
             Air
             included
             in
             the
             Gage
             to
             be
             very
             manifest
             ,
             and
             notable
             enough
             ,
             though
             not
             half
             ,
             or
             perhaps
             a
             quarter
             of
             the
             Air
             be
             pump'd
             out
             of
             the
             Receiver
             .
          
           
             6.
             
             You
             may
             also
             in
             such
             cases
             as
             these
             ,
             where
             the
             Receiver
             is
             large
             enough
             ,
             and
             is
             not
             to
             be
             quite
             exhausted
             ,
             make
             use
             of
             a
             Mercurial
             Gage
             ,
             differing
             from
             those
             above
             describ'd
             onely
             in
             this
             ,
             that
             the
             shorter
             leg
             need
             not
             be
             above
             an
             inch
             ,
             or
             half
             an
             inch
             long
             ,
             before
             it
             expand
             it self
             into
             a
             Bubble
             of
             about
             half
             an
             inch
             ,
             or
             an
             inch
             in
             Diameter
             ;
             and
             having
             at
             the
             upper
             part
             a
             very
             short
             and
             slender
             unseal'd
             Pipe
             ,
             at
             which
             the
             Air
             may
             get
             in
             and
             out
             :
             by
             which
             Contrivance
             you
             may
             have
             this
             Convenience
             ,
             that
             You
             need
             not
             include
             so
             much
             Air
             ,
             as
             otherwise
             would
             be
             requisite
             ,
             at
             the
             top
             of
             the
             longer
             Leg
             ,
             because
             the
             Mercury
             in
             the
             shorter
             cannot
             ,
             by
             reason
             of
             the
             breadth
             of
             the
             Bubble
             ,
             whereinto
             the
             Expansion
             of
             the
             Air
             drives
             it
             ,
             be
             considerably
             rais'd
             :
             Upon
             which
             account
             it
             becomes
             more
             easie
             to
             estimate
             by
             the
             Eye
             the
             degrees
             of
             the
             included
             Airs
             Rarefaction
             ,
             which
             may
             be
             done
             almost
             as
             easily
             ,
             as
             if
             there
             were
             water
             in
             stead
             of
             Mercury
             :
             provided
             it
             be
             remembred
             ,
             that
             Quick-silver
             by
             reason
             of
             its
             ponderousness
             ,
             does
             far
             more
             assist
             the
             dilatation
             of
             the
             Air
             ,
             then
             so
             much
             Water
             would
             do
             .
          
        
         
           
             EXPERIMENT
             XVIII
             .
          
           
             About
             an
             easie
             way
             to
             make
             the
             Pressure
             of
             the
             Air
             sensible
             to
             the
             Touch
             of
             those
             that
             doubt
             of
             it
             .
          
           
             THough
             several
             of
             our
             Experiments
             sufficiently
             manifest
             to
             the
             Skilful
             ,
             that
             the
             Pressure
             of
             the
             Air
             is
             very
             considerable
             ;
             yet
             because
             some
             of
             them
             require
             peculiar
             Glasses
             ,
             and
             other
             
             Instruments
             ,
             which
             are
             not
             always
             at
             hand
             ,
             and
             because
             there
             are
             many
             that
             think
             it
             surer
             to
             estimate
             the
             force
             of
             Pressure
             by
             what
             they
             immediately
             feel
             ,
             than
             by
             any
             other
             way
             ;
             I
             was
             invited
             for
             the
             sake
             of
             such
             to
             imploy
             an
             easie
             Experiment
             ,
             which
             usually
             proved
             convincing
             ,
             because
             it
             operated
             on
             that
             Sense
             ,
             whereon
             they
             chiefly
             rely'd
             .
          
           
             I
             caus'd
             then
             to
             be
             made
             a
             hollow
             (
             but
             strong
             )
             piece
             of
             Brass
             ,
             not
             above
             two
             or
             three
             inches
             high
             ,
             (
             that
             it
             might
             be
             in
             a
             trice
             exhausted
             ,
             )
             and
             open
             at
             both
             ends
             ,
             whose
             Orifices
             were
             Circular
             and
             parallel
             ,
             but
             not
             equal
             ,
             (
             the
             Instrument
             being
             made
             tapering
             ,
             so
             that
             it
             might
             be
             represented
             by
             an
             excavated
             
               Conus
               truncatus
            
             ,
             or
             a
             Gigg
             ,
             with
             the
             lower
             part
             cut
             transversly
             off
             .
             )
             This
             piece
             of
             Brass
             being
             cemented
             on
             ,
             as
             if
             it
             were
             a
             small
             Receiver
             to
             the
             Engine
             ,
             the
             Person
             ,
             that
             would
             not
             believe
             the
             Pressure
             of
             the
             Air
             to
             be
             near
             so
             considerable
             as
             was
             represented
             ,
             was
             bidden
             to
             lay
             the
             Palm
             of
             his
             Hand
             upon
             the
             upper
             Orifice
             ;
             and
             being
             ordered
             to
             lean
             a
             little
             upon
             it
             ,
             that
             so
             the
             lower
             part
             of
             his
             hand
             might
             prove
             a
             close
             Cover
             to
             the
             Orifice
             ,
             one
             Exuction
             of
             the
             Air
             was
             made
             by
             the
             help
             of
             the
             Pump
             :
             and
             then
             upon
             the
             withdrawing
             of
             the
             greatest
             part
             of
             the
             Pressure
             of
             the
             internal
             Air
             ,
             that
             before
             counterballanc'd
             that
             of
             the
             External
             ,
             the
             Hand
             being
             left
             alone
             to
             support
             the
             weight
             of
             the
             Ambient
             Air
             ,
             would
             be
             pressed
             inwards
             so
             forceably
             ,
             that
             though
             the
             stronger
             sort
             of
             men
             were
             able
             (
             though
             not
             without
             much
             adoe
             )
             to
             take
             off
             their
             Hands
             ,
             yet
             the
             weaker
             sort
             of
             Tryers
             could
             not
             do
             it
             ,
             (
             especially
             if
             by
             a
             second
             Suck
             the
             litle
             Receiver
             were
             better
             exhausted
             ,
             )
             but
             were
             fain
             to
             stay
             for
             the
             Return
             of
             the
             Air
             into
             the
             Receiver
             to
             assist
             them
             .
          
           
             This
             Experiment
             being
             design'd
             rather
             to
             convince
             than
             to
             punish
             those
             that
             were
             to
             make
             it
             ,
             we
             took
             care
             not
             onely
             that
             the
             Brass
             should
             be
             so
             thick
             ,
             and
             the
             Orifices
             so
             smooth
             ,
             that
             no
             Sharpness
             nor
             Roughness
             of
             the
             Metal
             should
             offend
             the
             Hand
             ;
             but
             also
             that
             the
             narrower
             Orifice
             (
             which
             was
             the
             oftenest
             made
             use
             of
             )
             should
             be
             but
             about
             an
             inch
             and
             a
             quarter
             in
             Diameter
             .
             
             But
             if
             any
             were
             desirous
             of
             a
             more
             sensible
             conviction
             ,
             't
             was
             very
             easie
             to
             give
             it
             him
             by
             making
             the
             larger
             Orifice
             the
             uppermost
             ,
             which
             was
             the
             reason
             why
             the
             Instrument
             was
             ,
             as
             we
             formerly
             noted
             ,
             made
             tapering
             .
             But
             yet
             this
             larger
             Orifice
             ought
             not
             to
             exceed
             2
             Inches
             ,
             or
             2
             Inches
             and
             1
             /
             2
             in
             wideness
             ,
             least
             the
             great
             Weight
             of
             the
             Air
             endanger
             the
             breaking
             or
             considerably
             hurting
             the
             Hand
             of
             the
             Experimenter
             .
             Which
             Caution
             I
             am
             put
             in
             mind
             of
             giving
             ,
             by
             remembring
             that
             I
             once
             much
             endangered
             my
             own
             Hand
             ,
             through
             the
             mistake
             of
             him
             that
             manag'd
             the
             Pump
             ,
             who
             unawares
             to
             me
             set
             it
             on
             work
             ,
             when
             ,
             for
             another
             purpose
             ,
             I
             had
             laid
             my
             Hand
             upon
             the
             Orifice
             of
             an
             Instrument
             of
             too
             great
             a
             Diameter
             .
          
           
             THe
             famous
             Experiment
             of
             Torricellius
             ,
             mentioned
             in
             the
             
               17
               th
            
             of
             our
             already
             published
             Tryals
             ,
             is
             of
             that
             Noblenesse
             and
             Importance
             ,
             that
             though
             divers
             Learned
             men
             have
             (
             but
             upon
             very
             differing
             principles
             )
             discours'd
             of
             it
             in
             Print
             ,
             which
             gives
             me
             the
             lesse
             mind
             to
             insist
             long
             upon
             it
             here
             ,
             yet
             I
             shall
             not
             scruple
             to
             subjoin
             some
             Notes
             concerning
             Tryals
             that
             I
             made
             ,
             (
             though
             for
             want
             of
             opportunity
             I
             could
             not
             repeat
             them
             according
             to
             my
             custom
             ,
             )
             which
             I
             had
             not
             met
             with
             in
             Others
             ,
             and
             which
             may
             serve
             to
             confirm
             the
             Hypothesis
             made
             use
             of
             in
             this
             Continuation
             ,
             and
             the
             Treatise
             it
             belongs
             to
             .
          
        
         
           
             EXPERIMENT
             XIX
             .
          
           
             About
             the
             Subsidence
             of
             Mercury
             in
             the
             Tube
             of
             the
             Torricellian
             Experiment
             to
             the
             level
             of
             the
             stagnant
             Mercury
             .
          
           
             A
             Baroscope
             being
             included
             in
             a
             Receiver
             ,
             made
             of
             a
             long
             Bolt
             head
             with
             the
             lower
             part
             of
             the
             Ball
             cut
             Circularly
             off
             ,
             upon
             the
             first
             Exuction
             of
             the
             Air
             ,
             the
             Quick-silver
             that
             before
             stood
             at
             29
             inches
             ,
             (
             the
             Atmosphere
             appearing
             then
             by
             a
             constant
             Baroscope
             very
             light
             ,
             )
             would
             fall
             so
             low
             as
             to
             rest
             at
             9
             or
             10
             inches
             ,
             
             (
             for
             once
             I
             measur'd
             the
             Subsidence
             beneath
             its
             former
             Elevation
             ,
             )
             and
             in
             about
             three
             Sucks
             more
             it
             would
             be
             brought
             quite
             down
             to
             the
             Level
             of
             the
             Stagnant
             Quick-silver
             ,
             and
             somewhat
             below
             ,
             (
             as
             t
             is
             the
             property
             of
             Quick-silver
             ,
             quite
             contrary
             to
             Water
             ,
             to
             rise
             less
             in
             a
             slender
             Pipe
             than
             in
             a
             wide
             .
             )
             The
             Air
             being
             let
             into
             the
             Receiver
             ,
             the
             Quick-silver
             would
             be
             impell'd
             up
             slowlier
             or
             faster
             ,
             as
             we
             pleas'd
             ,
             to
             the
             former
             height
             of
             29
             inches
             ,
             or
             thereabouts
             .
          
           
             NB.
             1.
             
             That
             if
             the
             Air
             were
             suffer'd
             to
             go
             hastily
             out
             of
             the
             Receiver
             ,
             the
             Mercury
             would
             ,
             by
             virtue
             of
             the
             accelerated
             motion
             acquir'd
             in
             its
             descent
             ,
             at
             the
             very
             first
             Suck
             descend
             till
             it
             reacht
             within
             an
             inch
             or
             two
             of
             the
             stagnant
             Mercury
             ,
             though
             it
             would
             presently
             after
             a
             few
             risings
             and
             fallings
             settle
             at
             the
             height
             of
             9
             or
             10
             inches
             ,
             till
             the
             next
             Suck
             brought
             it
             down
             lower
             .
          
           
             2.
             
             If
             when
             the
             Mercury
             was
             reimpell'd
             up
             to
             its
             due
             height
             ,
             those
             that
             manag'd
             the
             Pump
             did
             ,
             in
             stead
             of
             rarifying
             the
             Air
             ,
             a
             little
             compress
             it
             ,
             the
             Quick-silver
             would
             by
             the
             compress'd
             Air
             be
             easily
             made
             to
             rise
             an
             inch
             or
             more
             above
             the
             former
             standard
             of
             29
             inches
             .
             Which
             Circumstance
             I
             mention
             ,
             not
             as
             a
             new
             thing
             ,
             but
             to
             confirm
             (
             what
             some
             think
             strange
             )
             a
             Passage
             printed
             ,
             page
             the
             59
             th
             ,
             where
             I
             mention
             ,
             that
             if
             the
             Air
             in
             the
             Receiver
             ,
             in
             stead
             of
             being
             rarify'd
             in
             the
             Engine
             ,
             were
             a
             litle
             comprest
             by
             it
             ;
             the
             Pressure
             of
             the
             included
             Air
             ,
             being
             somewhat
             increas'd
             by
             having
             its
             Spring
             thus
             bent
             ,
             would
             sustain
             the
             Mercury
             in
             the
             Torricellian
             Tube
             at
             a
             greater
             than
             the
             wonted
             Height
             .
          
           
             And
             to
             confirm
             another
             passage
             in
             the
             same
             Page
             ,
             where
             I
             observ'd
             ,
             that
             if
             the
             Pressure
             of
             the
             Air
             upon
             the
             stagnant
             Mercury
             be
             not
             so
             great
             as
             t
             is
             wont
             to
             be
             ,
             the
             Mercury
             will
             begin
             to
             subside
             in
             a
             (
             fill'd
             and
             inverted
             )
             Tube
             ,
             which
             wants
             of
             the
             usual
             height
             ;
             we
             took
             a
             Glass
             Cane
             ,
             (
             seal'd
             at
             one
             end
             ,
             )
             much
             shorter
             than
             the
             due
             length
             ,
             and
             having
             fill'd
             it
             with
             Mercury
             ,
             and
             inverted
             it
             into
             a
             Glass
             full
             of
             stagnant
             Mercury
             ,
             we
             placed
             all
             in
             the
             former
             Receiver
             ;
             where
             the
             Mercurial
             Cylinder
             for
             want
             of
             the
             requisite
             height
             remain'd
             totally
             suspended
             ,
             but
             upon
             the
             first
             or
             
             second
             Suck
             it
             would
             subside
             ,
             and
             in
             two
             or
             three
             Sucks
             more
             it
             would
             fall
             to
             the
             levell
             of
             the
             stagnant
             Mercury
             ,
             or
             a
             little
             below
             it
             .
             Upon
             the
             letting
             in
             of
             the
             Air
             it
             would
             be
             impell'd
             to
             the
             very
             Top
             of
             the
             Tube
             ,
             bating
             an
             Aerial
             bubble
             ,
             which
             seem'd
             to
             come
             from
             the
             Mercury
             it self
             ,
             and
             was
             so
             little
             ,
             as
             not
             to
             be
             at
             all
             discernable
             ,
             save
             to
             a
             very
             attentive
             Eye
             .
          
           
             This
             Experiment
             I
             should
             not
             think
             fit
             here
             to
             relate
             ,
             
             since
             I
             formerly
             acquainted
             Your
             Lordship
             with
             the
             Subsidence
             of
             the
             Mercury
             upon
             the
             withdrawing
             of
             the
             Air
             from
             the
             Receiver
             ,
             were
             it
             not
             that
             ,
             in
             the
             mention
             of
             that
             Tryal
             ,
             I
             remember
             I
             confess'd
             to
             You
             ,
             that
             I
             could
             not
             so
             free
             the
             great
             Receiver
             I
             then
             us'd
             from
             Air
             ,
             but
             that
             the
             litle
             that
             remained
             or
             leak'd
             in
             ,
             made
             me
             unable
             to
             bring
             the
             Mercury
             in
             the
             Tube
             totally
             to
             subside
             ,
             or
             fall
             much
             nearer
             than
             within
             an
             Inch
             of
             the
             Surface
             of
             the
             stagnant
             Mercury
             ,
             with
             which
             in
             our
             present
             Tryals
             that
             in
             the
             Tube
             was
             brought
             to
             a
             Level
             .
          
        
         
           
             EXPERIMENT
             XX.
             
          
           
             Shewing
             that
             in
             Tubes
             open
             at
             both
             ends
             ,
             when
             no
             fuga
             Vacui
             can
             be
             pretended
             ,
             the
             weight
             of
             Water
             will
             raise
             Quick-silver
             no
             higher
             in
             slender
             than
             in
             larger
             Pipes
             .
          
           
             BEcause
             I
             find
             it
             ,
             even
             by
             Learned
             and
             very
             Late
             Writers
             ,
             urg'd
             as
             a
             clear
             and
             cogent
             Argument
             against
             those
             that
             ascribe
             the
             Phaenomena
             of
             the
             Torricellian
             Experiment
             to
             the
             weight
             of
             the
             External
             Air
             ;
             That
             t
             is
             impossible
             ,
             that
             the
             Air
             ,
             though
             't
             were
             granted
             to
             be
             a
             heavy
             Body
             ,
             could
             sustain
             the
             Quick-silver
             at
             the
             same
             height
             in
             Tubes
             of
             very
             differing
             bigness
             ,
             since
             the
             same
             Air
             cannot
             equally
             counterpoise
             Mercurial
             Cylinders
             of
             such
             unequal
             weights
             ;
             and
             because
             this
             Objection
             is
             wont
             very
             much
             to
             puzzle
             those
             that
             are
             not
             well
             acquainted
             with
             the
             Hydrostaticks
             ,
             I
             presume
             Your
             Lordship
             will
             allow
             me
             ,
             
             till
             I
             can
             shew
             you
             some
             Hydrostatical
             Papers
             ,
             by
             which
             the
             Objection
             may
             appear
             to
             be
             but
             ill
             grounded
             upon
             the
             true
             Theoremes
             of
             that
             Art
             ,
             to
             annex
             the
             Transcripts
             of
             a
             couple
             of
             Expeperiments
             ,
             (
             that
             I
             once
             made
             to
             remove
             this
             ,
             supposedly
             insuperable
             ,
             Difficulty
             ,
             )
             just
             as
             I
             find
             them
             registred
             in
             my
             Note-books
             .
          
           
             
               The
               I.
               Tryal
               .
               
                 Sept.
                 the
                 2.
                 1662.
                 
              
            
             
               We
               took
               a
               very
               large
               Glass-Tube
               ,
               Hermetically
               seal'd
               at
               one
               end
               ,
               and
               about
               two
               Foot
               and
               a
               half
               in
               Length
               .
               Into
               this
               we
               poured
               Quick-silver
               to
               the
               height
               of
               3
               or
               4
               fingers
               .
               Then
               we
               took
               a
               couple
               of
               Cylindrical
               Pipes
               of
               very
               unequal
               sizes
               ,
               (
               the
               wider
               being
               as
               big
               agen
               as
               the
               slenderer
               )
               and
               open
               at
               both
               Ends.
               The
               lower
               Ends
               of
               these
               two
               Pipes
               we
               thrust
               into
               the
               Quick-silver
               ,
               and
               fasten'd
               them
               near
               their
               upper
               Ends
               to
               the
               Tube
               with
               strings
               ,
               that
               they
               might
               not
               be
               lifted
               up
               ,
               nor
               mov'd
               out
               of
               their
               posture
               ,
               in
               which
               the
               convex
               Surface
               of
               the
               Mercury
               in
               both
               the
               Pipes
               seem'd
               to
               lie
               almost
               in
               a
               Level
               ,
               the
               Tube
               also
               it self
               being
               plac'd
               upright
               in
               a
               Frame
               .
               This
               done
               ,
               by
               the
               help
               of
               a
               Funnel
               we
               poured
               in
               Water
               by
               degrees
               at
               the
               top
               of
               the
               Tube
               ,
               and
               observ'd
               ,
               that
               as
               the
               Water
               gravitated
               more
               and
               more
               upon
               the
               stagnant
               Mercury
               ,
               so
               the
               included
               Mercury
               rose
               equally
               in
               both
               the
               Pipes
               ,
               till
               the
               Tube
               being
               almost
               fill'd
               with
               Water
               ,
               the
               Mercury
               appeared
               to
               be
               impell'd
               up
               to
               and
               sustain'd
               at
               as
               great
               a
               height
               in
               the
               Big
               Tube
               ,
               as
               in
               the
               Lesser
               ,
               being
               in
               either
               raised
               about
               two
               Inches
               above
               the
               Surface
               of
               the
               Stagnant
               Quick-silver
               .
            
             
               NB.
               1.
               
               Having
               caus'd
               about
               half
               the
               Water
               (
               having
               no
               conveniency
               to
               withdraw
               any
               more
               )
               in
               the
               Tube
               to
               be
               suck'd
               out
               at
               the
               Top
               ,
               we
               observ'd
               the
               Quick-silver
               in
               both
               the
               Tubes
               to
               subside
               uniformly
               ,
               and
               to
               reascend
               alike
               upon
               the
               reaffusion
               of
               the
               Water
               .
            
             
               2.
               
               We
               endeavoured
               to
               try
               the
               Experiment
               (
               for
               their
               sake
               who
               have
               not
               the
               Conveniency
               to
               have
               such
               Tubes
               purposely
               
               made
               )
               in
               a
               wooden
               vessel
               ,
               into
               which
               ,
               when
               it
               was
               fill'd
               with
               water
               ,
               we
               let
               down
               a
               flat
               Glass
               furnisht
               with
               stagnant
               Mercury
               ,
               whereinto
               the
               Ends
               of
               the
               two
               Pipes
               were
               immers'd
               .
               But
               the
               Opaeousness
               of
               the
               Cylinder
               (
               which
               reduced
               us
               to
               see
               onely
               from
               the
               Top
               the
               Reflection
               of
               the
               stagnant
               Mercury
               ,
               )
               and
               other
               Impediments
               ,
               disabled
               us
               to
               perceive
               the
               Motions
               and
               Stations
               of
               the
               Mercury
               in
               the
               Pipes
               ,
               though
               we
               once
               made
               use
               of
               a
               Candle
               the
               better
               to
               discern
               them
               .
            
          
           
             
               The
               II.
               Tryal
               .
            
             
               We
               took
               a
               very
               wide
               Tube
               of
               Glass
               ,
               of
               about
               a
               Foot
               long
               ,
               and
               into
               it
               poured
               a
               convenient
               Quantity
               of
               Quick-silver
               .
               We
               took
               also
               two
               Pipes
               of
               about
               equal
               length
               ,
               and
               of
               that
               disparity
               in
               Bigness
               that
               we
               newly
               mentioned
               ,
               (
               those
               Pipes
               lately
               described
               being
               indeed
               cut
               off
               from
               these
               we
               are
               now
               to
               speak
               of
               ,
               )
               and
               these
               being
               fill'd
               with
               Quick-silver
               (
               after
               the
               manner
               of
               the
               Torricellian
               Experiment
               )
               were
               by
               a
               certain
               Contrivance
               let
               down
               into
               the
               Tube
               ,
               and
               unstopt
               under
               the
               Surface
               of
               the
               stagnant
               Mercury
               ,
               and
               then
               the
               Quick-silver
               in
               the
               Pipes
               falling
               down
               to
               its
               wonted
               Station
               ,
               and
               resting
               there
               ,
               we
               poured
               into
               the
               Tube
               about
               a
               foot
               height
               (
               by
               Guess
               )
               of
               Water
               ,
               whereupon
               the
               Quick-silver
               as
               it
               before
               stood
               ,
               as
               it
               were
               ,
               in
               a
               Level
               in
               both
               the
               Pipes
               ,
               so
               it
               was
               ,
               for
               ought
               appear'd
               to
               us
               ,
               equally
               impell'd
               up
               beyond
               its
               wonted
               Station
               ,
               and
               sustain'd
               there
               both
               in
               the
               slender
               and
               in
               the
               bigger
               Pipe
               ,
               and
               upon
               the
               withdrawing
               of
               some
               of
               the
               Water
               it
               began
               to
               subside
               alike
               ,
               as
               to
               sense
               ,
               in
               them
               both
               ,
               falling
               no
               lower
               in
               the
               bigger
               than
               in
               the
               slenderer
               .
               And
               Water
               being
               a
               second
               time
               poured
               down
               into
               the
               Tube
               ,
               the
               Mercury
               did
               in
               both
               Pipes
               rise
               uniformly
               as
               before
               .
               By
               which
               and
               the
               former
               Experiment
               it
               sufficiently
               appeared
               ,
               that
               a
               Gravitating
               Liquor
               as
               Air
               or
               Water
               ,
               may
               impell
               or
               keep
               up
               Mercury
               to
               the
               same
               height
               in
               Tubes
               that
               are
               of
               very
               differing
               Capacities
               :
               And
               that
               Liquors
               ballance
               each
               other
               according
               to
               their
               Altitude
               ,
               and
               not
               barely
               according
               to
               their
               Weight
               .
               For
               in
               this
               last
               Experiment
               ,
               the
               Additional
               Cylinder
               of
               one
               Inch
               of
               Mercury
               was
               manifestly
               rais'd
               and
               kept
               
               up
               by
               the
               Water
               incumbent
               on
               the
               stagnant
               Mercury
               ,
               (
               the
               other
               Cause
               ,
               whatever
               it
               were
               ,
               of
               the
               Mercury's
               Suspension
               ,
               being
               able
               to
               sustain
               but
               a
               Cylinder
               shorter
               by
               an
               Inch.
               )
               And
               the
               same
               parcel
               of
               Water
               did
               counterpoise
               in
               the
               differing
               Pipes
               two
               Mercurial
               Cylinders
               ,
               which
               though
               but
               of
               the
               same
               Altitude
               ,
               (
               namely
               about
               an
               Inch
               )
               were
               of
               very
               unequal
               Weight
               .
            
          
        
         
           
             EXPERIMENT
             XXI
             .
          
           
             Of
             the
             Heights
             at
             which
             pure
             Mercury
             ,
             and
             Mercury
             Amalgam'd
             with
             Tin
             ,
             will
             stand
             in
             Barometers
             .
          
           
             COnsidering
             with
             my self
             ,
             that
             if
             the
             Sustentation
             of
             the
             Quick-silver
             in
             the
             Torricellian
             Experiment
             at
             a
             certain
             height
             ,
             depends
             upon
             the
             Aequilibrium
             ,
             which
             a
             Liquor
             of
             that
             Specifick
             Gravity
             does
             at
             such
             a
             height
             attain
             to
             with
             the
             External
             Air
             ,
             if
             that
             peculiar
             and
             determinate
             Gravity
             of
             the
             Quick-silver
             be
             altered
             ,
             the
             height
             of
             it
             ,
             requisite
             to
             an
             Aequilibrium
             with
             the
             Atmosphere
             ,
             must
             be
             altered
             too
             :
             (
             Considering
             this
             I
             say
             )
             I
             thought
             it
             might
             somewhat
             confirm
             the
             Hypothesis
             hitherto
             made
             use
             of
             ,
             if
             a
             Phaenomenon
             so
             agreeable
             to
             it
             were
             actually
             exhibited
             .
             This
             I
             supposed
             performable
             two
             differing
             wayes
             ,
             namely
             by
             mixing
             or
             (
             as
             Chymists
             speak
             )
             Amalgamating
             Mercury
             either
             with
             Gold
             ,
             to
             make
             it
             a
             mixture
             more
             heavy
             ,
             or
             with
             some
             other
             Metal
             that
             might
             make
             it
             more
             light
             than
             Mercury
             alone
             is
             .
             But
             the
             former
             of
             those
             two
             ways
             I
             forbore
             to
             prosecute
             being
             where
             I
             then
             was
             unfurnished
             with
             a
             sufficient
             quantity
             of
             refined
             Gold
             ,
             (
             for
             that
             which
             is
             Coyn'd
             is
             generally
             allayed
             with
             Silver
             ,
             or
             Copper
             ,
             or
             both
             ,
             )
             and
             therefore
             Amalgamating
             Mercury
             with
             a
             convenient
             proportion
             of
             pure
             Tin
             ,
             (
             or
             ,
             as
             the
             Tradesmen
             call
             it
             ,
             Block-Tin
             ,
             )
             that
             the
             mixture
             might
             not
             be
             too
             thick
             to
             be
             readily
             poured
             out
             into
             a
             Glass-Tube
             ,
             and
             to
             subside
             in
             it
             ,
             we
             fill'd
             with
             this
             Amalgam
             a
             Cylindrical
             Pipe
             ,
             sealed
             
             at
             one
             end
             ,
             and
             of
             a
             fit
             length
             ,
             and
             then
             inverted
             it
             into
             a
             litle
             Glass
             furnished
             with
             the
             like
             mixture
             .
             Of
             which
             Tryal
             the
             Event
             was
             ,
             that
             the
             Amalgam
             did
             not
             fall
             down
             to
             29
             ,
             nor
             even
             to
             30
             inches
             ,
             but
             stopt
             at
             31
             above
             the
             surface
             of
             the
             stagnant
             Mixture
             .
          
           
             Note
             1.
             
             That
             though
             one
             may
             expect
             ,
             that
             the
             Event
             of
             the
             Experiment
             would
             be
             the
             more
             considerable
             ,
             the
             Greater
             the
             Quantity
             is
             that
             is
             mingled
             of
             the
             light
             Metal
             ,
             yet
             care
             must
             be
             taken
             that
             the
             Amalgam
             be
             not
             made
             too
             thick
             ,
             least
             part
             of
             it
             stick
             here
             and
             there
             (
             as
             we
             did
             to
             our
             trouble
             find
             it
             apt
             to
             do
             )
             to
             the
             inside
             of
             the
             Pipe
             ,
             by
             which
             means
             some
             Aerial
             Corpuscles
             will
             meet
             with
             such
             convenient
             Receptacles
             ,
             as
             to
             make
             it
             very
             difficult
             ,
             if
             not
             almost
             impossible
             ,
             to
             free
             the
             Tube
             quite
             from
             Air.
             
          
           
             2.
             
             It
             may
             perhaps
             be
             worth
             while
             to
             try
             ,
             whether
             by
             comparing
             the
             height
             of
             the
             Amalgam
             ,
             to
             what
             it
             ought
             to
             be
             upon
             the
             score
             of
             the
             specifick
             Gravities
             of
             the
             Mercury
             ,
             and
             the
             Tin
             ,
             mingled
             in
             a
             known
             Proportion
             in
             the
             Amalgam
             ,
             any
             discovery
             may
             be
             made
             whether
             those
             two
             Metals
             do
             penetrate
             one
             another
             after
             such
             a
             manner
             (
             for
             there
             is
             no
             strict
             Penetration
             of
             Dimensions
             among
             Bodies
             )
             as
             Copper
             and
             Tin
             have
             ,
             as
             I
             elsewhere
             note
             ,
             been
             (
             by
             some
             Chymists
             )
             observ'd
             to
             do
             ,
             when
             being
             melted
             down
             together
             they
             make
             up
             a
             more
             close
             and
             specifically
             ponderous
             Body
             ,
             than
             their
             respective
             Weights
             seem'd
             to
             require
             .
          
           
             3.
             
             That
             by
             comparing
             this
             21.
             
             Experiment
             with
             the
             18
             th
             of
             those
             formerly
             published
             ,
             it
             may
             appear
             ,
             that
             the
             height
             of
             the
             Liquor
             ,
             suspended
             in
             the
             Torricellian
             Experiment
             ,
             depends
             so
             much
             upon
             its
             aequilibrium
             with
             the
             outward
             Air
             ,
             that
             it
             may
             be
             varied
             by
             a
             change
             of
             Gravity
             in
             either
             of
             the
             two
             Bodies
             that
             counterballance
             each
             other
             ,
             whether
             the
             change
             be
             of
             weight
             in
             the
             Atmosphere
             ,
             or
             of
             Specifick
             Gravity
             in
             the
             suspended
             Liquor
             .
          
        
         
           
           
             Advertisement
             .
          
           
             I
             Should
             here
             acquaint
             Your
             Lordship
             with
             what
             I
             have
             since
             tried
             in
             reference
             to
             the
             18
             th
             of
             the
             Printed
             Experiments
             ,
             where
             I
             mention
             ,
             that
             I
             observed
             ,
             by
             long
             keeping
             the
             same
             Instrument
             with
             which
             I
             once
             made
             the
             Torricellian
             Experiment
             in
             the
             same
             place
             ,
             that
             the
             height
             of
             the
             suspended
             Mercury
             would
             vary
             according
             as
             the
             weight
             of
             the
             Atmosphere
             hapned
             to
             change
             .
             But
             though
             about
             the
             Barometer
             (
             as
             others
             have
             by
             their
             imitation
             allowed
             me
             to
             call
             the
             Instrument
             hitherto
             mentioned
             ,
             put
             into
             a
             Frame
             )
             I
             made
             in
             the
             year
             1660
             several
             Observations
             ,
             that
             would
             not
             perhaps
             be
             impertinent
             in
             this
             place
             ,
             yet
             having
             long
             since
             left
             them
             with
             a
             Friend
             ,
             who
             lives
             far
             off
             ,
             and
             not
             having
             them
             now
             in
             my
             power
             ,
             I
             must
             beg
             Your
             Lordships
             permission
             to
             reserve
             them
             for
             a
             part
             of
             the
             Appendix
             ,
             which
             I
             doubt
             I
             shall
             be
             engaged
             to
             adde
             to
             this
             Epistle
             .
             And
             in
             the
             mean
             time
             I
             shall
             not
             forbear
             to
             present
             Your
             Lordship
             those
             other
             Papers
             that
             I
             have
             by
             me
             ,
             relating
             to
             the
             Barometer
             ;
             some
             of
             which
             will
             ,
             I
             presume
             ,
             sufficiently
             confirm
             my
             lately
             mentioned
             conjecture
             about
             the
             cause
             of
             the
             Variation
             observed
             in
             the
             Height
             of
             the
             suspended
             Mercury
             .
          
        
         
           
             EXPERIMENT
             XXII
             .
          
           
             Wherein
             is
             propos'd
             a
             way
             of
             making
             Barometers
             ,
             that
             may
             be
             transported
             even
             to
             distant
             Countries
             .
          
           
             THinking
             it
             a
             desireable
             thing
             (
             as
             I
             have
             elsewhere
             intimated
             )
             to
             be
             able
             to
             compare
             together
             ,
             by
             the
             help
             of
             Barometers
             ,
             the
             weight
             of
             the
             Atmosphere
             at
             the
             same
             time
             ,
             not
             onely
             in
             differing
             parts
             of
             the
             same
             Country
             ,
             as
             of
             England
             ,
             but
             in
             differing
             Regions
             of
             the
             World
             ;
             I
             could
             not
             but
             foresee
             that
             't
             would
             be
             very
             difficult
             to
             accomplish
             my
             desire
             without
             altering
             the
             form
             of
             the
             Barometers
             I
             had
             hitherto
             made
             use
             of
             .
             For
             as
             these
             be
             
             unfit
             to
             be
             transported
             far
             ,
             because
             that
             stagnant
             Mercury
             would
             be
             so
             apt
             to
             spill
             .
             So
             the
             procuring
             them
             to
             be
             made
             in
             the
             places
             where
             they
             are
             to
             be
             used
             ,
             though
             it
             be
             no
             bad
             expedient
             ,
             and
             such
             as
             I
             have
             divers
             times
             made
             use
             of
             ,
             is
             liable
             to
             this
             inconvenience
             ;
             that
             ,
             besides
             that
             few
             will
             take
             the
             pains
             ,
             and
             have
             the
             skill
             ,
             requisite
             to
             make
             Baroscopes
             well
             ,
             though
             they
             be
             sufficiently
             furnished
             with
             Glasses
             and
             Mercury
             for
             that
             purpose
             ,
             besides
             this
             ,
             I
             say
             ,
             except
             men
             be
             more
             than
             ordinarily
             diligent
             and
             skilful
             ,
             (
             and
             perhaps
             though
             they
             be
             ,
             )
             't
             will
             be
             very
             difficult
             to
             be
             sure
             that
             the
             Baroscope
             newly
             made
             in
             a
             remote
             Country
             ,
             is
             as
             Good
             (
             and
             but
             as
             good
             )
             as
             that
             which
             a
             man
             makes
             use
             of
             in
             this
             ;
             in
             regard
             that
             at
             the
             making
             of
             the
             former
             ,
             they
             are
             supposed
             to
             have
             no
             other
             Baroscope
             to
             compare
             it
             with
             ;
             and
             to
             be
             sure
             ,
             they
             have
             not
             the
             same
             with
             which
             it
             is
             to
             be
             compared
             Here.
             
          
           
             Being
             by
             these
             considerations
             invited
             to
             attempt
             the
             making
             of
             Portable
             or
             Travailing
             Baroscopes
             ,
             (
             if
             I
             may
             so
             call
             them
             ,
             )
             I
             thought
             it
             requisite
             to
             endeavour
             these
             three
             things
             :
             The
             first
             ,
             to
             make
             the
             vessel
             that
             should
             contain
             both
             the
             sustained
             and
             the
             stagnant
             Mercury
             all
             of
             one
             piece
             of
             Glass
             ,
             of
             a
             like
             bigness
             :
             The
             next
             ,
             to
             place
             this
             vessel
             ,
             when
             fill'd
             ,
             in
             such
             a
             Frame
             ,
             as
             may
             be
             easie
             to
             be
             transported
             ,
             and
             yet
             in
             a
             reasonable
             measure
             defend
             the
             Glass
             from
             external
             violence
             ,
             no
             part
             of
             it
             standing
             quite
             out
             of
             the
             Frame
             ,
             as
             in
             all
             other
             Baroscopes
             :
             And
             the
             third
             ,
             so
             to
             order
             the
             vessel
             ,
             that
             it
             may
             not
             be
             subject
             to
             be
             easily
             broken
             by
             the
             violent
             motion
             of
             the
             Mercury
             contain'd
             in
             it
             .
          
           
             The
             first
             of
             these
             will
             not
             seem
             practicable
             to
             those
             that
             imagine
             (
             without
             any
             warrant
             from
             the
             Hydrostaticks
             )
             that
             t
             is
             as
             well
             necessary
             as
             usual
             ,
             that
             the
             stagnant
             Mercury
             should
             have
             a
             vessel
             much
             wider
             than
             the
             Tube
             ,
             wherein
             the
             Mercurial
             Cylinder
             is
             sustain'd
             ;
             but
             to
             us
             the
             difficulty
             seem'd
             much
             less
             to
             make
             the
             Glass
             part
             of
             our
             Tube
             of
             one
             piece
             ,
             and
             of
             a
             convenient
             shape
             ,
             than
             afterwards
             to
             fill
             it
             .
          
           
             But
             to
             do
             both
             ,
             we
             took
             a
             Glass
             Cylinder
             seal'd
             at
             one
             end
             ,
             and
             of
             a
             convenient
             length
             ,
             (
             as
             about
             4
             or
             5
             foot
             ,
             )
             and
             caus'd
             it
             by
             
             the
             flame
             of
             a
             Lamp
             to
             be
             so
             bent
             ,
             that
             ,
             to
             those
             that
             did
             not
             take
             notice
             't
             was
             sealed
             at
             one
             end
             ,
             it
             seem'd
             to
             be
             a
             Syphon
             of
             very
             unequal
             Legs
             ,
             the
             one
             being
             3
             or
             4
             times
             longer
             than
             the
             other
             ;
             by
             virtue
             of
             which
             Figure
             the
             shorter
             Leg
             may
             serve
             in
             stead
             of
             the
             distinct
             vessel
             usually
             imployed
             to
             contain
             the
             stagnant
             Mercury
             .
             To
             fill
             this
             ,
             which
             is
             not
             easie
             ,
             one
             may
             proceed
             after
             this
             manner
             .
             Take
             a
             small
             Funnel
             of
             Glass
             ,
             with
             a
             long
             and
             slender
             Shank
             ,
             so
             that
             it
             may
             reach
             3
             or
             4
             Inches
             ,
             or
             further
             ,
             into
             the
             shorter
             Leg
             of
             our
             Barometrical
             Syphon
             (
             if
             I
             may
             so
             call
             it
             ;
             )
             and
             by
             this
             Funnel
             pour
             into
             this
             shorter
             Leg
             as
             much
             Mercury
             as
             may
             reach
             about
             2
             or
             3
             Inches
             in
             both
             Legs
             ;
             then
             stopping
             the
             Orifice
             with
             your
             finger
             ,
             and
             slowly
             inclining
             the
             Tube
             ,
             the
             Mercury
             in
             the
             longer
             Leg
             will
             gently
             fall
             to
             the
             sealed
             end
             ;
             and
             the
             Air
             that
             was
             there
             before
             ,
             will
             pass
             by
             it
             ,
             and
             so
             make
             it
             room
             .
             The
             Mercury
             in
             the
             shorter
             Leg
             (
             which
             Leg
             ought
             to
             be
             held
             uppermost
             )
             will
             by
             the
             same
             inclination
             of
             the
             Tube
             fall
             towards
             the
             Orifice
             ,
             but
             ,
             being
             by
             the
             finger
             that
             stops
             that
             ,
             kept
             from
             falling
             out
             ,
             if
             you
             do
             slowly
             reerect
             the
             Glass
             ,
             and
             then
             make
             it
             stoop
             again
             as
             much
             as
             before
             ,
             the
             Mercury
             will
             pass
             out
             of
             the
             shorter
             Leg
             into
             the
             longer
             ,
             and
             joyn
             with
             that
             which
             was
             there
             before
             ;
             and
             if
             all
             the
             Mercury
             do
             not
             so
             pass
             ,
             the
             Orifice
             is
             to
             be
             stopt
             again
             with
             your
             Finger
             ,
             and
             the
             Tube
             inclin'd
             as
             formerly
             .
             This
             done
             ,
             the
             Tube
             is
             to
             be
             erected
             ,
             and
             by
             the
             help
             of
             the
             Funnel
             more
             Mercury
             is
             to
             be
             poured
             in
             ,
             and
             the
             foregoing
             process
             of
             stopping
             the
             Orifice
             ,
             inclining
             the
             Tube
             &c.
             is
             to
             be
             repeated
             ,
             till
             all
             the
             Mercury
             pour'd
             into
             the
             shorter
             Leg
             ,
             be
             brought
             to
             joyn
             with
             that
             in
             the
             longer
             ;
             and
             then
             the
             open
             Leg
             is
             to
             be
             furnisht
             with
             fresh
             Mercury
             ,
             observing
             this
             ,
             that
             the
             nearer
             the
             longer
             Leg
             comes
             to
             the
             being
             fill'd
             ,
             the
             less
             you
             must
             raise
             it
             from
             time
             to
             time
             ,
             when
             you
             pour
             Mercury
             into
             the
             shorter
             ;
             as
             also
             ,
             that
             when
             you
             see
             the
             longer
             Leg
             quite
             full
             of
             Mercury
             ,
             (
             though
             there
             be
             but
             litle
             in
             the
             shorter
             ,
             )
             you
             need
             not
             pour
             in
             any
             more
             ,
             if
             the
             longer
             do
             much
             exceed
             a
             Yard
             ;
             because
             upon
             the
             restoring
             of
             the
             Tube
             to
             an
             erected
             posture
             there
             will
             
             subside
             from
             the
             taller
             leg
             into
             the
             other
             a
             pretty
             quantity
             of
             Mercury
             ,
             by
             reason
             of
             the
             space
             at
             the
             seal'd
             end
             ,
             which
             will
             be
             deserted
             by
             the
             Mercury
             that
             was
             there
             .
             But
             because
             t
             is
             difficult
             by
             this
             way
             ,
             as
             well
             as
             by
             that
             practised
             already
             ,
             to
             fill
             a
             Tube
             with
             Mercury
             without
             leaving
             any
             visible
             bubbles
             ;
             to
             free
             it
             from
             such
             (
             if
             any
             happen
             to
             be
             )
             you
             must
             once
             more
             stop
             the
             Orifice
             with
             your
             finger
             ,
             and
             incline
             ,
             and
             reerect
             the
             Tube
             divers
             times
             ,
             till
             you
             have
             thereby
             brought
             most
             of
             the
             smaller
             bubbles
             into
             one
             greater
             ;
             (
             which
             you
             may
             if
             you
             please
             increase
             ,
             by
             letting
             in
             a
             little
             Air
             :
             )
             for
             by
             making
             this
             Great
             bubblle
             pass
             leisurely
             two
             or
             three
             times
             from
             one
             end
             of
             the
             Tube
             to
             the
             other
             ,
             it
             will
             in
             its
             passage
             as
             it
             were
             lick
             up
             all
             the
             small
             Bubbles
             ,
             and
             unite
             them
             to
             its
             self
             ;
             which
             may
             afterwards
             by
             one
             inclination
             more
             of
             the
             Tube
             be
             made
             to
             pass
             into
             the
             shorter
             Leg
             ,
             and
             thence
             into
             the
             free
             Air.
             
          
           
             But
             there
             is
             another
             sort
             of
             Funnels
             ,
             which
             if
             one
             have
             the
             skill
             and
             conveniency
             to
             make
             ,
             (
             as
             
               I.
               M.
            
             easily
             doth
             ,
             )
             one
             may
             very
             expeditiously
             fill
             the
             bended
             Tubes
             of
             our
             portable
             Barometers
             .
             For
             if
             you
             make
             the
             slender
             part
             of
             the
             Funnel
             not
             streight
             but
             bended
             ,
             in
             the
             form
             of
             an
             Obtuse
             Angle
             ,
             and
             of
             such
             a
             length
             ,
             that
             the
             part
             which
             is
             to
             go
             into
             the
             shorter
             Leg
             of
             our
             Siphon
             may
             reach
             to
             the
             Flexure
             (
             of
             the
             Siphon
             ;
             )
             then
             you
             may
             ,
             by
             so
             holding
             the
             Tube
             that
             the
             sealed
             end
             be
             somewhat
             lower
             than
             the
             other
             ,
             and
             by
             pouring
             in
             Mercury
             at
             the
             Obtuse
             end
             of
             the
             Angular
             Funnel
             ,
             easily
             make
             it
             run
             over
             the
             Flexure
             into
             the
             longer
             Leg
             of
             the
             Siphon
             ;
             provided
             you
             do
             now
             and
             then
             ,
             as
             occasion
             requires
             ,
             erect
             a
             litle
             and
             shake
             the
             Tube
             ,
             to
             help
             the
             Mercury
             to
             get
             by
             the
             Air
             ,
             and
             expell
             it
             .
          
           
             By
             such
             wayes
             as
             these
             we
             have
             found
             by
             Experience
             ,
             that
             t
             is
             possible
             (
             though
             not
             easie
             )
             to
             do
             in
             such
             a
             bended
             Glass
             ,
             as
             our
             purpose
             requires
             ,
             what
             ,
             besides
             a
             very
             late
             Learned
             Writer
             ,
             the
             Diligent
             Mersennus
             himself
             ,
             admonishes
             his
             Reader
             ,
             that
             t
             is
             not
             a
             practicable
             thing
             to
             do
             in
             the
             Ordinary
             Glasses
             of
             the
             Torricellian
             Experiment
             ,
             viz.
             to
             free
             the
             Mercury
             of
             a
             straight
             Tube
             from
             
             Air
             and
             Bubbles
             ,
             (
             s
             as
             to
             be
             able
             by
             inclining
             the
             Glass
             to
             make
             the
             Liquor
             ascend
             to
             the
             very
             top
             .
             )
          
           
             The
             First
             of
             our
             3
             above
             mentioned
             Scopes
             being
             thus
             attained
             ,
             it
             was
             not
             difficult
             to
             compass
             the
             Second
             ,
             by
             the
             help
             of
             a
             solid
             piece
             of
             Wood
             ,
             which
             is
             to
             be
             somewhat
             longer
             than
             the
             Tube
             ,
             and
             a
             good
             deal
             broader
             in
             the
             lower
             part
             than
             in
             the
             upper
             ,
             that
             it
             may
             receive
             the
             shorter
             Leg
             of
             the
             Siphon
             .
             In
             such
             a
             piece
             of
             Wood
             ,
             which
             was
             about
             an
             Inch
             thick
             ,
             we
             caus'd
             to
             be
             made
             a
             Gutter
             or
             Channel
             ,
             of
             such
             a
             depth
             and
             shape
             ,
             that
             our
             Siphon
             might
             be
             placed
             in
             it
             so
             deep
             ,
             that
             a
             flat
             piece
             of
             Wood
             (
             like
             a
             plain'd
             Lath
             )
             might
             be
             layd
             upon
             it
             ,
             without
             at
             all
             pressing
             upon
             or
             so
             much
             as
             touching
             the
             Glass
             ;
             so
             that
             this
             piece
             of
             Wood
             may
             serve
             for
             a
             Cover
             to
             defend
             the
             Glass
             ,
             to
             be
             put
             on
             when
             the
             Instrument
             is
             to
             be
             transported
             ,
             and
             taken
             off
             again
             when
             t
             is
             to
             be
             hung
             up
             to
             make
             Observations
             with
             ;
             the
             Channel-piece
             of
             wood
             serving
             both
             for
             a
             part
             of
             a
             Case
             ,
             and
             for
             an
             entire
             Frame
             ;
             which
             may
             for
             some
             uses
             be
             a
             litle
             more
             commodious
             ,
             if
             the
             Cover
             be
             joyned
             (
             as
             it
             may
             easily
             be
             )
             to
             the
             rest
             of
             the
             Frame
             ,
             by
             2
             or
             3
             litle
             Hinges
             and
             a
             Hasp
             ,
             by
             whose
             help
             the
             Case
             may
             be
             readily
             opened
             and
             shut
             at
             pleasure
             .
          
           
             The
             3
             d
             thing
             we
             proposed
             to
             our selves
             is
             nothing
             near
             so
             easie
             as
             the
             2
             d
             ,
             nor
             have
             we
             yet
             had
             opportunity
             to
             try
             ,
             whether
             the
             way
             we
             made
             use
             of
             will
             hold
             ,
             if
             the
             Barometer
             be
             transported
             into
             very
             remote
             parts
             ,
             though
             by
             smaller
             Removes
             we
             found
             cause
             to
             hope
             that
             't
             will
             succeed
             in
             Greater
             .
          
           
             The
             Grand
             difficulty
             to
             be
             obviated
             was
             this
             ;
             That
             though
             't
             were
             easie
             to
             hinder
             the
             spilling
             of
             the
             Mercury
             ,
             by
             stopping
             the
             Orifice
             of
             the
             shorter
             Leg
             of
             our
             Siphon
             ,
             yet
             that
             would
             not
             serve
             the
             turn
             ;
             for
             the
             upper
             part
             of
             the
             Tube
             being
             destitute
             of
             Air
             ,
             if
             the
             Mercury
             be
             by
             the
             motion
             of
             the
             Instrument
             put
             to
             vibrate
             ,
             it
             will
             be
             apt
             (
             for
             want
             of
             meeting
             with
             any
             Air
             in
             the
             upper
             part
             of
             the
             Tube
             to
             check
             its
             motions
             )
             to
             hit
             so
             violently
             against
             the
             Top
             of
             the
             Glass
             as
             to
             beat
             it
             out
             ,
             or
             to
             crack
             some
             of
             the
             neighbouring
             parts
             .
          
           
           
             To
             obviate
             this
             great
             inconvenience
             our
             way
             is
             ,
             to
             incline
             the
             Tube
             ,
             till
             the
             Mercury
             be
             impell'd
             to
             the
             very
             top
             of
             it
             ,
             and
             yet
             there
             will
             remain
             a
             competent
             quantity
             in
             the
             shorter
             leg
             of
             the
             Glass
             ,
             if
             that
             be
             not
             at
             first
             made
             too
             short
             .
             This
             done
             ,
             the
             remaining
             part
             of
             the
             shorter
             Leg
             is
             to
             be
             quite
             fill'd
             up
             either
             with
             Water
             or
             Mercury
             ,
             and
             the
             Orifice
             of
             it
             is
             to
             be
             very
             carefully
             and
             firmly
             stopt
             ,
             (
             for
             which
             purpose
             we
             use
             our
             strong
             black
             Cement
             :
             )
             for
             by
             this
             means
             the
             Mercury
             in
             the
             longer
             Leg
             ,
             having
             no
             room
             to
             play
             ,
             cannot
             strike
             with
             violence
             as
             before
             ,
             against
             the
             top
             of
             the
             Glass
             .
             But
             though
             by
             many
             times
             successively
             shaking
             the
             Baroscope
             we
             did
             not
             perceive
             that
             't
             was
             very
             like
             to
             be
             prejudiced
             by
             the
             shakes
             it
             must
             necessarily
             indure
             in
             Transportation
             to
             remote
             places
             ,
             if
             due
             care
             be
             had
             of
             it
             by
             the
             way
             ,
             yet
             till
             further
             Tryal
             have
             been
             made
             I
             shall
             not
             pretend
             to
             be
             certain
             of
             the
             Event
             .
             But
             thus
             much
             of
             conveniency
             we
             have
             already
             found
             in
             this
             Contrivance
             ,
             that
             we
             sent
             it
             some
             miles
             off
             to
             the
             top
             of
             a
             Hill
             ,
             and
             had
             it
             brought
             home
             safe
             again
             ,
             the
             phaenomena
             at
             the
             top
             and
             bottom
             of
             the
             Hill
             being
             answerable
             to
             what
             we
             might
             have
             expected
             if
             we
             had
             imployed
             another
             Baroscope
             .
          
           
             When
             the
             Instrument
             is
             to
             be
             sent
             away
             ,
             the
             height
             of
             the
             Mercurial
             Cylinder
             (
             to
             be
             measured
             from
             the
             surface
             of
             the
             stagnant
             Mercury
             in
             the
             shorter
             Leg
             )
             being
             taken
             for
             that
             place
             ,
             day
             ,
             and
             hour
             ,
             and
             compar'd
             (
             if
             it
             may
             be
             )
             with
             that
             of
             another
             good
             Baroscope
             ,
             which
             is
             to
             continue
             in
             that
             place
             ;
             as
             much
             of
             the
             Gutter
             as
             is
             unfill'd
             by
             the
             Glass
             may
             be
             well
             stuffed
             with
             Cotten
             ,
             or
             some
             such
             thing
             ,
             to
             keep
             the
             Glass
             the
             more
             firm
             in
             its
             posture
             ;
             and
             that
             the
             Tube
             be
             not
             shaken
             or
             press'd
             against
             the
             Wood
             ,
             some
             of
             the
             same
             matter
             may
             be
             put
             between
             the
             rest
             of
             the
             Frame
             and
             the
             Cover
             ,
             which
             ought
             to
             be
             well
             bound
             together
             .
             And
             when
             the
             Instrument
             is
             arriv'd
             at
             the
             remote
             place
             where
             t
             is
             to
             be
             imployed
             ,
             (
             for
             if
             it
             be
             to
             be
             sent
             but
             a
             litle
             way
             ,
             it
             may
             be
             carried
             safely
             without
             using
             any
             adventitious
             Liquor
             ,
             )
             the
             Water
             that
             is
             added
             ,
             may
             be
             taken
             off
             again
             ,
             by
             soaking
             it
             up
             with
             pieces
             of
             Sponge
             ,
             Linnen
             ,
             &c.
             but
             if
             in
             stead
             of
             Water
             you
             put
             in
             Mercury
             ,
             
             as
             it
             ought
             to
             have
             been
             put
             in
             by
             Weight
             ,
             so
             it
             is
             to
             be
             taken
             out
             ,
             till
             you
             have
             just
             the
             Weight
             that
             was
             put
             in
             :
             and
             t
             is
             not
             difficult
             to
             take
             out
             the
             Mercury
             by
             degrees
             ,
             by
             the
             help
             of
             a
             small
             Glass-pipe
             ,
             since
             You
             may
             either
             suck
             up
             litle
             by
             little
             as
             much
             as
             remains
             of
             the
             additional
             Mercury
             ,
             when
             by
             erecting
             the
             Barometer
             ,
             and
             warily
             unstopping
             the
             Orifice
             of
             the
             lower
             Leg
             ,
             as
             much
             Mercury
             as
             will
             of
             its
             self
             flow
             out
             is
             efflux'd
             ;
             or
             else
             you
             may
             take
             out
             the
             superfluous
             Mercury
             ,
             by
             thrusting
             the
             lower
             end
             of
             the
             litle
             Pipe
             into
             that
             Liquor
             ,
             and
             when
             it
             has
             taken
             in
             enough
             ,
             stopping
             the
             upper
             end
             close
             with
             your
             finger
             ,
             to
             keep
             it
             from
             falling
             back
             again
             when
             you
             remove
             the
             Pipe.
             
          
           
             NB.
             If
             it
             should
             happen
             in
             a
             long
             voyage
             ,
             that
             by
             the
             numerous
             Shakings
             of
             the
             Instrument
             there
             should
             from
             the
             additional
             Water
             or
             Mercury
             in
             the
             shorter
             Leg
             get
             up
             into
             the
             longer
             any
             litle
             Aerial
             Bubble
             ,
             which
             seems
             the
             onely
             (
             but
             I
             hope
             not
             likely
             )
             danger
             in
             this
             Contrivance
             ,
             he
             that
             is
             to
             use
             the
             Instrument
             ,
             at
             the
             end
             of
             the
             Voyage
             may
             ,
             if
             he
             be
             skilful
             ,
             free
             the
             Mercury
             from
             it
             by
             the
             same
             way
             ,
             that
             we
             lately
             prescrib'd
             to
             free
             it
             from
             Air
             ,
             when
             the
             Instrument
             was
             first
             fill'd
             .
          
           
             I
             presume
             I
             need
             not
             tell
             Your
             Lordship
             ,
             that
             the
             chief
             use
             of
             this
             Travailing
             Baroscope
             is
             ,
             That
             he
             that
             uses
             it
             in
             a
             remote
             part
             ,
             keeping
             a
             Diary
             of
             the
             heights
             of
             the
             Mercury
             ,
             by
             comparing
             these
             heights
             with
             those
             at
             which
             the
             Mercury
             stood
             at
             the
             same
             times
             in
             the
             Barometer
             that
             was
             not
             remov'd
             ,
             the
             Agreement
             or
             Difference
             of
             the
             weight
             of
             the
             Atmosphere
             in
             distant
             places
             may
             be
             observed
             .
             To
             which
             this
             may
             be
             added
             ,
             the
             Conveniency
             ,
             which
             the
             structure
             of
             these
             Instruments
             gives
             them
             to
             be
             securely
             let
             down
             into
             deep
             Wels
             or
             Mines
             ,
             and
             to
             be
             drawn
             up
             to
             the
             top
             of
             Towers
             and
             Steeples
             ,
             and
             other
             elevated
             places
             :
             not
             here
             to
             consider
             ,
             whether
             by
             a
             convenient
             addition
             ,
             these
             ,
             as
             well
             as
             some
             other
             Barometers
             ,
             may
             not
             be
             made
             to
             discover
             even
             very
             minute
             Alterations
             of
             the
             Atmospheres
             Pressure
             .
          
           
             Whether
             this
             Travailing
             Baroscope
             ,
             being
             furnish'd
             at
             its
             upper
             end
             with
             a
             very
             good
             Ball
             and
             Socket
             ,
             and
             at
             the
             lower
             end
             
             with
             a
             great
             weight
             ,
             (
             which
             way
             of
             keeping
             things
             steady
             in
             a
             Ship
             has
             been
             happily
             used
             by
             the
             
               Royal
               Society
            
             on
             another
             occasion
             ,
             )
             whether
             ,
             I
             say
             ,
             our
             Instrument
             may
             by
             this
             Contrivance
             ,
             or
             some
             other
             that
             might
             be
             suggested
             to
             the
             same
             purpose
             ,
             be
             made
             any
             thing
             serviceable
             at
             Sea
             ,
             notwithstanding
             the
             differing
             motions
             of
             the
             Ship
             ,
             I
             have
             had
             no
             opportunity
             to
             try
             :
             but
             whether
             it
             may
             or
             may
             not
             be
             useful
             in
             spite
             of
             the
             rolling
             of
             the
             Ship
             ,
             it
             may
             at
             least
             be
             made
             use
             of
             in
             flat
             Calms
             ,
             (
             which
             divers
             times
             happen
             in
             long
             Voyages
             ,
             especially
             to
             the
             East-Indies
             ,
             and
             to
             Africk
             ,
             )
             and
             then
             the
             Instrument
             ,
             which
             at
             other
             times
             may
             lie
             by
             without
             being
             at
             all
             cumbersom
             ,
             may
             be
             made
             use
             of
             ,
             as
             long
             as
             the
             Calm
             lasts
             ,
             to
             acquaint
             the
             Observer
             with
             the
             weight
             of
             the
             Atmosphere
             in
             the
             Climate
             where
             he
             is
             ,
             and
             that
             upon
             the
             Sea
             :
             which
             may
             give
             some
             welcome
             Information
             to
             the
             Curiosity
             of
             Speculative
             Naturalists
             ,
             and
             perhaps
             prove
             either
             more
             directly
             or
             in
             its
             consequences
             of
             some
             use
             to
             Navigators
             themselves
             ,
             as
             by
             enabling
             them
             by
             its
             suddain
             changes
             to
             foretell
             the
             end
             of
             the
             Calme
             .
             Besides
             that
             ,
             having
             one
             of
             these
             Instruments
             ready
             at
             hand
             ,
             where
             ever
             they
             set
             foot
             on
             shore
             ,
             though
             it
             be
             but
             upon
             a
             small
             Island
             ,
             or
             a
             Rock
             ,
             they
             can
             presently
             and
             easily
             take
             notice
             of
             the
             Gravity
             of
             the
             Atmosphere
             in
             that
             place
             ;
             which
             whether
             or
             no
             ,
             if
             compared
             with
             other
             Observations
             ,
             it
             may
             in
             time
             prove
             not
             altogether
             useless
             to
             the
             Guessing
             whereabouts
             they
             are
             ,
             and
             the
             foreseeing
             some
             aproaching
             changes
             of
             Weather
             ,
             I
             leave
             to
             future
             Experience
             ,
             if
             it
             shall
             be
             thought
             worth
             the
             making
             ,
             to
             determine
             .
          
           
             Besides
             the
             ordinary
             Baroscope
             ,
             and
             this
             Travailing
             one
             ,
             I
             have
             imployed
             2
             or
             3
             other
             Instruments
             of
             quite
             differing
             kinds
             ,
             to
             discover
             the
             varying
             Gravities
             of
             the
             Atmosphere
             ;
             but
             though
             they
             have
             hitherto
             succeeded
             well
             (
             for
             the
             main
             ,
             )
             yet
             being
             willing
             to
             make
             further
             Observations
             about
             them
             ,
             I
             reserve
             one
             of
             them
             for
             another
             opportunity
             ,
             and
             think
             fit
             to
             leave
             the
             other
             in
             a
             Tract
             it
             belongs
             to
             .
          
        
         
           
           
             A
             Post-script
             Advertisment
             .
          
           
             SInce
             the
             writing
             of
             the
             foregoing
             and
             the
             following
             Experiments
             about
             the
             Travailing
             Baroscope
             ,
             having
             had
             occasion
             to
             make
             one
             at
             a
             place
             about
             50
             miles
             distant
             from
             that
             where
             I
             was
             when
             I
             writ
             them
             ,
             I
             took
             notice
             ,
             that
             the
             Mercury
             in
             the
             Travailing
             Baroscope
             was
             not
             by
             1
             /
             4
             of
             an
             Inch
             so
             high
             as
             that
             in
             another
             Baroscope
             made
             the
             ordinary
             way
             ;
             and
             yet
             't
             was
             not
             easie
             to
             perceive
             ,
             that
             the
             former
             had
             been
             less
             carefully
             fill'd
             than
             the
             latter
             .
             So
             that
             I
             yet
             know
             not
             well
             to
             what
             cause
             to
             impute
             the
             Difference
             ,
             unless
             it
             should
             perhaps
             depend
             upon
             this
             Circumstance
             ;
             That
             the
             Pipe
             ,
             whereof
             the
             Travailing
             Baroscope
             was
             made
             ,
             was
             very
             slender
             ,
             and
             much
             more
             so
             than
             the
             Tube
             of
             the
             other
             ;
             and
             I
             have
             already
             elsewhere
             observed
             ,
             that
             Mercury
             ,
             contrary
             to
             what
             happens
             in
             Water
             ,
             is
             lesse
             apt
             to
             rise
             in
             very
             slender
             Pipes
             .
             And
             though
             I
             remember
             that
             ,
             at
             the
             Place
             where
             I
             writ
             the
             Experiment
             ,
             to
             which
             this
             Postscript
             belongs
             ,
             in
             the
             Tube
             I
             then
             imployed
             to
             make
             the
             Travailing
             Baroscope
             ,
             the
             Mercury
             ascended
             as
             high
             as
             in
             a
             noted
             one
             made
             the
             common
             way
             ,
             yet
             not
             being
             in
             the
             other
             place
             furnished
             with
             a
             Tube
             long
             and
             big
             enough
             ,
             I
             think
             my self
             oblig'd
             ,
             till
             I
             can
             clear
             the
             Doubt
             by
             further
             Tryal
             ,
             to
             give
             Your
             Lordship
             this
             Advertisement
             ,
             lest
             either
             the
             Cause
             already
             suspected
             ,
             or
             some
             other
             unheeded
             thing
             may
             in
             some
             cases
             make
             these
             Travailing
             Baroscopes
             somewhat
             differing
             from
             others
             .
             But
             though
             they
             should
             prove
             to
             be
             so
             ,
             yet
             it
             would
             not
             follow
             that
             they
             cannot
             be
             made
             serviceable
             :
             for
             keeping
             a
             pretty
             while
             that
             Instrument
             ,
             which
             suggested
             the
             Scruple
             to
             me
             ,
             just
             by
             the
             other
             with
             which
             I
             had
             compar'd
             it
             ,
             and
             carefully
             taking
             notice
             of
             the
             respective
             heights
             at
             which
             the
             Mercury
             rested
             in
             both
             ,
             I
             observ'd
             that
             when
             it
             rose
             or
             fell
             in
             the
             other
             Barometer
             ,
             it
             did
             also
             rise
             and
             fall
             in
             the
             Portable
             one
             ;
             and
             when
             it
             rested
             at
             its
             first
             station
             in
             the
             Fromer
             ,
             it
             did
             so
             in
             the
             Later
             ;
             and
             though
             there
             seem'd
             to
             be
             an
             inequality
             in
             the
             quantity
             of
             the
             Ascent
             ,
             and
             subsidence
             of
             the
             Mercury
             in
             the
             two
             Instruments
             ,
             yet
             that
             seem'd
             to
             be
             accountable
             for
             by
             some
             Circumstances
             ,
             
             especially
             the
             very
             unequal
             breadth
             of
             the
             vessel
             that
             contain'd
             the
             stagnant
             Mercury
             in
             the
             other
             Barometer
             ,
             and
             that
             shorter
             Leg
             which
             answer'd
             to
             that
             vessel
             in
             the
             Travailing
             Barometer
             .
             But
             till
             the
             formerly
             proposed
             Scruple
             be
             by
             further
             Observation
             removed
             ,
             the
             safest
             way
             will
             be
             to
             make
             the
             Barometer
             to
             be
             sent
             to
             remote
             places
             ,
             as
             like
             as
             may
             be
             (
             in
             highness
             ,
             and
             length
             of
             the
             Tube
             )
             to
             another
             Portable
             one
             kept
             at
             home
             ;
             that
             so
             when
             they
             are
             once
             adjusted
             ,
             the
             Collations
             may
             be
             made
             betwixt
             two
             Instruments
             of
             the
             same
             kind
             ,
             whereof
             that
             which
             is
             kept
             at
             home
             may
             also
             ,
             if
             it
             be
             thought
             fit
             ,
             be
             compared
             ,
             when
             the
             Observations
             are
             made
             ,
             with
             a
             Baroscope
             made
             the
             ordinary
             way
             .
          
        
         
           
             EXPERIMENT
             XXIII
             .
          
           
             Confirming
             ,
             that
             Mercury
             in
             a
             Barometer
             will
             be
             kept
             suspended
             higher
             at
             the
             top
             ,
             than
             at
             the
             bottom
             of
             a
             Hill.
             On
             which
             occasion
             something
             is
             noted
             about
             the
             height
             of
             Mountains
             ,
             especially
             the
             Pic
             of
             Tenariff
             .
          
           
             TO
             give
             Your
             Lordship
             some
             Instance
             (
             till
             I
             can
             present
             You
             with
             a
             Nobler
             one
             )
             of
             the
             Use
             of
             our
             Travailing
             Barometer
             ,
             I
             shall
             now
             adde
             :
             That
             when
             I
             writ
             the
             foregoing
             Experiment
             ,
             chancing
             to
             be
             within
             2
             or
             3
             miles
             of
             a
             Hill
             ,
             which
             ,
             though
             not
             high
             ,
             was
             the
             least
             low
             in
             that
             Countrey
             ,
             I
             thought
             our
             Instrument
             might
             be
             sfely
             ,
             and
             not
             altogether
             uselesly
             ,
             carried
             on
             Horse-back
             to
             the
             top
             of
             it
             ,
             which
             was
             too
             remote
             from
             the
             bottom
             to
             be
             conveniently
             reacht
             by
             me
             on
             foot
             in
             the
             midst
             of
             Winter
             .
             This
             Tryal
             therefore
             I
             resolv'd
             to
             make
             ,
             because
             ,
             though
             I
             formerly
             told
             you
             of
             a
             considerable
             one
             that
             had
             been
             made
             in
             France
             by
             some
             Eminent
             Virtuosi
             of
             the
             Country
             ,
             yet
             I
             was
             willing
             ,
             not
             onely
             to
             have
             a
             Proof
             how
             safely
             our
             Baroscope
             might
             be
             transported
             ,
             but
             to
             confirm
             to
             Your
             Lordship
             upon
             our
             own
             Observation
             ,
             made
             in
             another
             Region
             ,
             so
             considerable
             
             an
             Argument
             ,
             as
             these
             kind
             of
             Experiments
             afford
             to
             our
             Hypothesis
             :
          
           
             And
             though
             when
             I
             came
             to
             try
             the
             Experiment
             ,
             I
             hapned
             to
             have
             an
             Indisposition
             that
             forbid
             me
             to
             do
             it
             all
             my Self
             ,
             yet
             having
             carefully
             mark'd
             on
             the
             edge
             of
             the
             Frame
             the
             height
             to
             which
             the
             suspended
             Quick-silver
             reach'd
             ,
             and
             compar'd
             it
             with
             a
             good
             Baroscope
             made
             the
             ordinary
             way
             ,
             I
             commmitted
             our
             Instrument
             to
             a
             couple
             of
             Servants
             ,
             that
             I
             had
             often
             imployed
             about
             Pneumatical
             and
             Mercurial
             Experiments
             ,
             giving
             them
             particular
             Instructions
             what
             to
             do
             .
             And
             the
             Instrument
             being
             such
             as
             might
             be
             safely
             carried
             on
             Horseback
             ,
             I
             had
             in
             two
             or
             three
             hours
             an
             Account
             brought
             me
             back
             ,
             the
             Summe
             of
             which
             was
             :
             That
             they
             found
             the
             suspended
             Mercury
             fall
             a
             litle
             as
             they
             ascended
             the
             Hill
             ,
             at
             whose
             Top
             they
             gave
             the
             Liquor
             leave
             to
             setle
             ,
             and
             carefully
             took
             notice
             by
             a
             mark
             of
             the
             Place
             it
             rested
             at
             ;
             which
             was
             ;
             as
             I
             afterwards
             found
             ,
             ¼
             of
             an
             Inch
             ,
             or
             somewhat
             better
             beneath
             the
             Mark
             I
             had
             made
             ,
             and
             this
             notwithstanding
             the
             Hill
             was
             not
             high
             ,
             and
             the
             Air
             and
             Wind
             seem'd
             to
             them
             to
             be
             much
             colder
             at
             the
             top
             of
             it
             ,
             than
             beneath
             .
             But
             though
             ,
             as
             they
             descended
             more
             and
             more
             ,
             they
             observ'd
             the
             Mercury
             to
             rise
             again
             higher
             and
             higher
             ,
             (
             as
             being
             press'd
             against
             by
             a
             taller
             column
             of
             the
             Atmosphere
             ,
             )
             and
             though
             consequently
             the
             Experiment
             agreed
             very
             well
             with
             our
             Hypothesis
             ,
             and
             may
             serve
             for
             a
             Confirmation
             of
             it
             ;
             yet
             by
             reason
             of
             the
             small
             height
             of
             the
             Mountain
             the
             Decrement
             of
             the
             height
             of
             the
             Mercurial
             Cylinder
             was
             not
             so
             considerable
             ,
             but
             that
             I
             should
             perhaps
             have
             omitted
             the
             mention
             of
             this
             Tryal
             ,
             if
             it
             did
             not
             shew
             that
             our
             Travailing
             Baroscopes
             may
             be
             fit
             to
             be
             imployed
             about
             such
             Experiments
             .
             And
             therefore
             ,
             when
             I
             can
             recover
             some
             of
             my
             scatter'd
             Papers
             ,
             I
             shall
             by
             way
             of
             Appendix
             subjoin
             to
             this
             some
             other
             Observations
             ,
             that
             I
             procur'd
             to
             be
             made
             by
             Ingenious
             men
             ,
             who
             had
             the
             Opportunity
             of
             living
             near
             higher
             Mountains
             .
          
           
             Some
             further
             Tryals
             I
             have
             recommended
             to
             be
             hereafter
             made
             by
             some
             other
             inquisitive
             Persons
             ;
             and
             to
             make
             them
             the
             
             more
             instructive
             ,
             I
             could
             wish
             that
             others
             would
             do
             what
             I
             should
             have
             done
             ,
             if
             Opportunity
             had
             befriended
             me
             .
             For
             I
             design'd
             to
             make
             the
             Experiment
             at
             the
             bottom
             ,
             the
             top
             ,
             and
             the
             intermediate
             part
             of
             the
             hill
             ,
             at
             three
             differing
             constitutions
             of
             Air
             ;
             viz.
             when
             it
             should
             appear
             by
             a
             good
             ordinary
             Baroscope
             ,
             that
             the
             Atmosphere
             was
             very
             heavy
             ,
             when
             it
             should
             be
             found
             to
             be
             very
             light
             ,
             and
             when
             it
             should
             have
             a
             moderate
             degree
             of
             Gravity
             :
             And
             I
             hoped
             ,
             that
             if
             sagacious
             Experimenters
             should
             make
             these
             diversity'd
             Observations
             on
             distant
             and
             unequal
             Hils
             ,
             good
             Hints
             may
             result
             from
             the
             Collations
             that
             may
             be
             made
             of
             the
             varying
             Decrements
             of
             the
             Mercurial
             Cylinders
             height
             ,
             according
             to
             the
             differing
             Gravities
             of
             the
             Atmosphere
             at
             several
             Times
             ,
             and
             the
             differing
             heights
             of
             the
             Hils
             and
             Stations
             where
             the
             Observations
             should
             be
             made
             .
          
           
             I
             also
             indeavoured
             to
             get
             a
             Baroscope
             carried
             down
             to
             the
             bottoms
             of
             deep
             Mines
             ;
             partly
             ,
             to
             try
             whether
             the
             Atmospherical
             Pillar
             being
             longer
             There
             then
             at
             the
             Top
             ,
             the
             Mercury
             in
             the
             Tube
             would
             not
             be
             impell'd
             up
             higher
             ;
             and
             partly
             ,
             in
             order
             to
             other
             Discoveries
             .
             But
             some
             Impediments
             in
             the
             structure
             of
             those
             Mines
             made
             it
             not
             very
             Practicable
             to
             imploy
             Barometers
             there
             ;
             which
             yet
             makes
             me
             not
             despair
             of
             Success
             in
             some
             other
             Mines
             ,
             where
             the
             Shafts
             or
             Pits
             are
             sunck
             more
             perpendicularly
             .
          
           
             Perhaps
             I
             told
             Your
             Lordship
             already
             by
             word
             of
             mouth
             ,
             that
             I
             have
             been
             sollicitously
             endeavouring
             to
             get
             the
             Torricellian
             Experiment
             tried
             upon
             the
             Pic
             of
             Teneriff
             ,
             but
             hitherto
             I
             have
             had
             no
             Account
             of
             the
             success
             of
             my
             Endeavours
             ;
             for
             which
             I
             am
             the
             more
             concern'd
             ,
             because
             of
             the
             Eminent
             (
             if
             not
             Matchless
             )
             height
             of
             the
             Mountain
             ,
             of
             which
             You
             may
             receive
             some
             Satisfaction
             ,
             by
             what
             I
             am
             going
             to
             subjoin
             about
             it
             .
          
           
             
             
               An
               Appendix
               about
               the
               height
               of
               Mountains
               .
            
             
               FOrasmuch
               as
               on
               the
               one
               hand
               not
               onely
               Kepler
               ,
               but
               divers
               other
               modern
               Writers
               of
               Note
               ,
               do
               endeavour
               to
               straiten
               the
               Atmosphere
               ,
               and
               make
               it
               lower
               by
               half
               than
               the
               least
               height
               to
               which
               ,
               according
               to
               our
               Estimation
               ,
               it
               should
               reach
               ;
               and
               to
               countenance
               their
               Opinion
               ,
               will
               not
               allow
               the
               Clouds
               to
               be
               often
               above
               a
               Mile
               high
               ,
               (
               nor
               even
               the
               highest
               Mountains
               to
               exceed
               two
               miles
               .
               )
               And
               forasmuch
               as
               on
               the
               other
               side
               other
               Learned
               men
               seem
               to
               make
               the
               Clouds
               and
               the
               Mountains
               of
               a
               stupendous
               height
               ;
               we
               ,
               who
               take
               a
               middle
               way
               of
               estimating
               the
               height
               of
               the
               one
               and
               the
               other
               ,
               hold
               it
               not
               unfit
               to
               subjoyn
               on
               this
               occasion
               some
               uncommon
               Observations
               ,
               in
               favour
               of
               our
               Opinion
               ,
               that
               we
               have
               obtain'd
               from
               inquisitive
               Travellers
               .
            
             
               But
               first
               I
               will
               subjoyn
               a
               Passage
               I
               have
               somewhere
               met
               with
               in
               Ricciolus
               his
               
                 Almigestum
                 novum
              
               ,
               where
               he
               (
               if
               I
               well
               remember
               )
               relates
               ,
               that
               the
               
                 Rector
                 Metensis
              
               (
               as
               he
               calls
               him
               )
               of
               the
               Jesuites
               Colledg
               affirm'd
               to
               him
               some
               years
               since
               ,
               that
               he
               had
               measured
               the
               height
               of
               many
               Clouds
               ,
               without
               having
               found
               any
               of
               them
               higher
               than
               5000
               paces
               :
               which
               argues
               ,
               that
               he
               met
               with
               some
               so
               high
               ,
               though
               indeed
               the
               height
               of
               Clouds
               must
               needs
               bevery
               various
               ,
               according
               to
               the
               Gravity
               or
               Lightness
               ,
               Density
               or
               Thinness
               ,
               Rest
               or
               Agitation
               of
               the
               Air
               ,
               and
               the
               condition
               of
               the
               Vapors
               &
               Exhaltations
               they
               consist
               of
               .
               And
               if
               either
               that
               be
               true
               which
               we
               have
               formerly
               had
               occasion
               to
               mention
               concerning
               Maignan's
               Observation
               ,
               or
               if
               it
               be
               true
               that
               Sublunary
               Comets
               (
               for
               I
               speak
               not
               of
               Celestial
               ones
               )
               are
               Generated
               of
               Exhalations
               of
               the
               Terrestrial
               Globe
               ,
               we
               may
               well
               conjecture
               that
               the
               Atmosphere
               ,
               (
               especially
               if
               its
               height
               be
               not
               uniform
               ,
               )
               and
               even
               Clouds
               (
               especially
               those
               that
               have
               most
               Fumes
               ,
               and
               fewest
               Vapors
               )
               may
               reach
               much
               higher
               than
               
                 Cardan
                 ,
                 Kepler
              
               ,
               and
               others
               have
               defin'd
               .
            
             
               But
               of
               the
               height
               of
               Clouds
               (
               which
               we
               have
               sometimes
               attempted
               to
               take
               Geometrically
               )
               we
               may
               have
               elsewhere
               occasion
               
               to
               speak
               again
               ;
               and
               therefore
               I
               shall
               now
               proceed
               to
               what
               I
               have
               to
               say
               concerning
               the
               Height
               of
               Mountains
               .
               Which
               being
               an
               Enquiry
               curious
               and
               difficult
               enough
               in
               it self
               ,
               and
               of
               some
               Importance
               in
               the
               Disquisition
               about
               the
               height
               of
               the
               Atmosphere
               ,
               (
               it
               being
               evident
               that
               That
               must
               reach
               at
               least
               as
               high
               as
               the
               tops
               of
               Mountains
               ,
               upon
               whose
               tops
               men
               can
               live
               ;
               )
               I
               hope
               it
               will
               not
               be
               unacceptable
               to
               Your
               Lordship
               ,
               if
               having
               a
               while
               since
               (
               as
               I
               was
               intimating
               )
               had
               the
               opportunity
               to
               discourse
               with
               some
               credible
               Persons
               that
               have
               been
               upon
               the
               top
               of
               exceeding
               high
               mountains
               ,
               particularly
               of
               the
               Pic
               of
               Tenariff
               ,
               (
               and
               especially
               with
               one
               Gentleman
               ,
               who
               was
               a
               few
               dayes
               before
               brought
               to
               satisfie
               the
               Curiosity
               of
               our
               Inquisitive
               and
               Discerning
               Monarch
               ,
               by
               giving
               him
               an
               Account
               of
               his
               Journey
               ,
               )
               I
               acquaint
               You
               with
               those
               of
               the
               Particulars
               ,
               which
               I
               learn'd
               from
               thence
               ,
               that
               are
               the
               most
               pertinent
               to
               our
               present
               purpose
               .
               First
               then
               whereas
               divers
               late
               Mathematicians
               will
               not
               allow
               above
               two
               miles
               or
               half
               a
               German
               league
               (
               and
               some
               of
               them
               not
               half
               so
               much
               )
               to
               the
               height
               of
               the
               highest
               Mountain
               ;
               the
               Mountain
               we
               speak
               of
               ,
               in
               the
               Island
               of
               Tenariff
               ,
               one
               of
               the
               Canaries
               or
               Fortunate
               Islands
               ,
               so
               high
               ,
               that
               ,
               though
               perhaps
               I
               think
               those
               Travellers
               I
               have
               taken
               notice
               of
               ,
               speak
               with
               the
               most
               when
               they
               write
               ,
               that
               the
               top
               of
               this
               Mountain
               is
               to
               be
               seen
               at
               Sea
               4
               degrees
               off
               ,
               
                 i.
                 e.
              
               at
               least
               threescore
               German
               Leagues
               ;
               yet
               having
               ask'd
               the
               ingenious
               Gentleman
               lately
               mentioned
               ,
               Mr.
               Sydenham
               ,
               from
               what
               distance
               the
               top
               of
               the
               Sugar-loaf
               (
               or
               highest
               part
               of
               the
               Hill
               ,
               so
               called
               from
               its
               Figure
               )
               could
               be
               seen
               at
               Sea
               ,
               according
               to
               the
               common
               opinion
               of
               Seamen
               ?
               he
               answer'd
               ,
               that
               that
               Distance
               was
               wont
               to
               be
               reckon'd
               60
               Sea-leagues
               ,
               of
               3
               miles
               to
               a
               League
               :
               adding
               ,
               that
               he
               himself
               had
               seen
               it
               about
               40
               leagues
               off
               ,
               and
               yet
               it
               appear'd
               exceeding
               high
               ,
               and
               like
               a
               blewish
               Pyramid
               ,
               manifestly
               a
               great
               deal
               higher
               than
               the
               Clouds
               .
               And
               what
               he
               related
               to
               me
               about
               the
               Distance
               ,
               was
               afterwards
               confirmed
               by
               the
               Answers
               I
               receiv'd
               from
               observing
               men
               of
               differing
               Nations
               ,
               who
               had
               sail'd
               that
               way
               ;
               and
               particularly
               by
               a
               Noble
               Virtuoso
               ,
               skill'd
               in
               the
               Mathematicks
               ,
               
               who
               was
               then
               Admiral
               of
               a
               brave
               English
               Fleet
               :
               And
               the
               above
               mentioned
               Gentleman
               (
               M
               r
               S.
               )
               also
               told
               me
               ,
               that
               sometimes
               men
               could
               from
               thence
               see
               the
               Island
               of
               Madera
               ,
               though
               distant
               from
               it
               70
               leagues
               ;
               and
               that
               the
               Great
               Canary
               ,
               though
               18
               leagues
               off
               ,
               seem'd
               to
               be
               very
               near
               them
               that
               were
               on
               the
               top
               of
               the
               Sugar-loaf
               ,
               as
               if
               they
               might
               leap
               down
               upon
               it
               :
               Thus
               far
               M
               r
               Sydenham
               .
               By
               whose
               Relation
               it
               appears
               ,
               that
               this
               Pic
               must
               be
               far
               higher
               than
               Kepler
               and
               others
               allow
               Mountains
               to
               be
               :
               for
               else
               it
               could
               not
               be
               seen
               at
               Sea
               from
               so
               great
               a
               Distance
               .
               And
               the
               Learned
               Ricciolus
               supposing
               it
               to
               be
               (
               as
               some
               Navigators
               report
               it
               to
               be
               )
               discoverable
               at
               Sea
               4
               degrees
               off
               ,
               calculates
               its
               height
               measur'd
               by
               a
               Perpendicular
               line
               ,
               and
               allowing
               too
               for
               Refraction
               ,
               to
               amount
               to
               Ten
               miles
               ,
               which
               Altitude
               also
               the
               accurate
               Snellius
               assigns
               it
               .
               But
               I
               fear
               this
               Learned
               man
               may
               have
               been
               somewhat
               misinform'd
               by
               the
               Navigators
               he
               relyes
               on
               ,
               or
               else
               that
               the
               way
               of
               allowing
               for
               Refractions
               is
               not
               yet
               reduc'd
               to
               a
               sufficient
               Certainty
               .
               For
               I
               do
               not
               find
               by
               those
               who
               have
               purposely
               gone
               to
               the
               top
               of
               it
               ,
               that
               the
               Mountain
               is
               so
               high
               as
               his
               Calculation
               makes
               it
               .
               And
               whereas
               the
               same
               Eminent
               Writer
               resolutely
               ponounces
               that
               the
               Height
               of
               mount
               Caucasus
               ,
               Deduction
               being
               made
               for
               Refraction
               ,
               is
               51
               Bolonian
               miles
               ,
               (
               which
               are
               considerably
               greater
               than
               the
               Roman
               miles
               ,
               )
               I
               doubt
               that
               here
               likewise
               ,
               though
               I
               question
               not
               his
               Supputations
               if
               You
               grant
               him
               the
               Grounds
               of
               them
               ,
               he
               makes
               this
               Mountain
               far
               higher
               than
               indeed
               it
               is
               .
               For
               the
               Passage
               of
               Aristotle
               ,
               on
               which
               he
               founds
               his
               Opinion
               ,
               is
               obscure
               enough
               ;
               and
               Aristotle
               ,
               himself
               does
               sometimes
               take
               up
               Reports
               upon
               Hear-say
               ,
               without
               over-strictly
               examining
               their
               Truth
               or
               Probability
               ;
               whereas
               all
               the
               Navigators
               and
               Travellers
               I
               have
               hitherto
               met
               with
               ,
               (
               and
               Your
               Lordship
               knows
               ,
               that
               I
               have
               upon
               a
               Publick
               Account
               the
               opportunity
               of
               meeting
               often
               with
               such
               men
               ,
               )
               do
               almost
               unanimously
               agree
               ,
               that
               the
               Pic
               of
               Teneriff
               is
               the
               highest
               Mountain
               hitherto
               known
               in
               the
               World
               ,
               and
               yet
               that
               is
               so
               far
               from
               being
               15
               leagues
               high
               ,
               (
               as
               some
               Eminent
               and
               even
               late
               Writers
               would
               perswade
               us
               ,
               )
               
               that
               it
               is
               scarce
               a
               7
               th
               part
               so
               high
               as
               Ricciolus
               computes
               Mount
               Caucasus
               to
               be
               .
               For
               having
               ask'd
               M
               r
               Sydenham
               ,
               and
               others
               ,
               what
               was
               the
               Estimate
               made
               by
               the
               most
               knowing
               Persons
               of
               the
               Island
               of
               the
               height
               of
               the
               Hill
               ,
               he
               told
               me
               that
               his
               Guides
               accounted
               it
               to
               be
               one
               and
               twenty
               mile
               high
               from
               the
               Town
               called
               L'oretava
               ,
               seated
               on
               the
               lower
               part
               of
               the
               Hill
               ;
               from
               which
               .
               town
               to
               the
               Sea
               there
               is
               3
               miles
               of
               way
               alwayes
               descending
               .
               But
               in
               regard
               that
               the
               way
               ,
               which
               amounted
               to
               21
               miles
               in
               length
               ,
               is
               ,
               as
               other
               wayes
               whereby
               steep
               places
               are
               wont
               to
               be
               ascended
               ,
               made
               to
               wind
               and
               turn
               for
               the
               conveniency
               of
               Travellers
               ;
               I
               can
               scarce
               deduct
               less
               than
               2
               thirds
               for
               the
               Crookedness
               of
               the
               way
               :
               and
               accordingly
               having
               ask'd
               him
               ,
               whether
               the
               Perpendicular
               height
               of
               it
               had
               been
               accurately
               taken
               by
               any
               with
               Mathematical
               Instruments
               ,
               he
               answered
               ,
               that
               he
               could
               say
               nothing
               to
               that
               upon
               his
               own
               knowledg
               ,
               but
               that
               a
               Sea-man
               with
               great
               confidence
               affirmed
               himself
               to
               have
               accurately
               enough
               measur'd
               it
               by
               Observations
               made
               in
               a
               Ship
               ,
               and
               to
               have
               found
               the
               Perpendicular
               height
               of
               the
               Hill
               to
               be
               about
               7
               miles
               .
               Which
               Estimate
               agrees
               well
               enough
               with
               the
               Calculations
               of
               Ricciolus
               and
               Snellius
               ,
               if
               we
               lessen
               the
               Distance
               from
               which
               the
               top
               of
               the
               Hill
               is
               to
               be
               discovered
               ,
               from
               60
               German
               leagues
               of
               4
               miles
               to
               a
               League
               ,
               to
               the
               like
               number
               of
               common
               Leagues
               at
               3
               miles
               to
               a
               League
               .
            
             
               And
               because
               eminent
               Writers
               have
               so
               confidently
               deliver'd
               prodigious
               things
               touching
               the
               height
               of
               this
               Mountain
               ,
               I
               will
               here
               ,
               to
               confirm
               the
               Estimate
               already
               made
               ,
               adde
               these
               Particulars
               ,
               which
               I
               took
               from
               the
               Gentleman
               's
               own
               mouth
               ,
               (
               and
               which
               were
               afterwards
               confirm'd
               to
               me
               by
               another
               that
               went
               with
               him
               ,
               and
               partly
               also
               by
               a
               3
               d
               ,
               who
               went
               up
               to
               the
               top
               at
               another
               time
               of
               the
               Year
               ,
               )
               viz.
               That
               they
               begun
               their
               Journey
               from
               L'oretava
               on
               the
               18
               th
               of
               August
               ,
               about
               10
               of
               the
               Clock
               at
               night
               ,
               and
               travell'd
               till
               Five
               in
               the
               Afternoon
               on
               the
               Munday
               following
               ,
               resting
               two
               Hours
               by
               the
               way
               ,
               and
               travelling
               about
               10
               miles
               of
               their
               way
               upon
               Mules
               ,
               which
               afterwards
               they
               were
               forc'd
               to
               leave
               ,
               and
               betake
               themselves
               to
               their
               feet
               .
               Resting
               upon
               Munday
               till
               
               midnight
               ,
               they
               resum'd
               their
               journeying
               ,
               and
               travell'd
               till
               about
               Nine
               the
               next
               morning
               ,
               at
               which
               time
               they
               arriv'd
               at
               the
               top
               of
               the
               Sugar-loaf
               ,
               or
               highest
               Pile
               of
               the
               Mountain
               ;
               so
               that
               they
               travell'd
               in
               all
               but
               26
               hours
               ,
               in
               which
               ,
               considering
               the
               steepness
               and
               ruggedness
               of
               the
               ways
               ,
               and
               that
               they
               were
               forc't
               to
               goe
               above
               half
               way
               on
               foot
               ,
               to
               which
               they
               were
               unaccustomed
               ,
               t
               is
               likely
               enough
               that
               the
               length
               of
               the
               way
               did
               not
               much
               ,
               if
               at
               all
               ,
               exceed
               the
               Computation
               of
               the
               Guides
               .
            
             
               We
               have
               since
               endeavour'd
               ,
               but
               without
               yet
               knowing
               what
               will
               be
               the
               succes
               ,
               to
               have
               the
               height
               of
               this
               Mountain
               carefully
               taken
               by
               skilful
               men
               .
               In
               the
               interim
               I
               shall
               not
               deny
               ,
               but
               that
               if
               what
               Aristotle
               and
               other
               Authors
               report
               of
               Mount
               Caucasus
               be
               true
               ,
               there
               may
               be
               far
               higher
               Mountains
               than
               the
               Pic
               of
               Tenariff
               ;
               especially
               since
               there
               is
               one
               Consideration
               ,
               which
               perhaps
               You
               will
               not
               think
               despicable
               ,
               that
               I
               find
               not
               taken
               notice
               of
               by
               those
               that
               have
               written
               of
               the
               height
               of
               Mountains
               ;
               viz.
               That
               of
               two
               Mountains
               that
               ,
               
               measur'd
               by
               Geometrical
               Instruments
               ,
               may
               appear
               to
               be
               of
               the
               same
               height
               ,
               there
               may
               yet
               be
               a
               Great
               inequality
               ;
               because
               the
               Measurer
               measures
               onely
               from
               some
               plain
               piece
               of
               Ground
               at
               the
               bottom
               of
               the
               Hill
               to
               the
               top
               ,
               whereas
               it
               may
               be
               ,
               that
               the
               Country
               ,
               wherein
               one
               of
               those
               Mountains
               stands
               ,
               may
               be
               exceedingly
               much
               higher
               than
               that
               wherein
               the
               other
               is
               plac'd
               :
               which
               difference
               of
               heights
               in
               the
               several
               Countreys
               ,
               he
               that
               is
               to
               measure
               onely
               the
               height
               of
               one
               of
               the
               Mountains
               ,
               is
               not
               wont
               to
               take
               any
               Notice
               of
               ;
               and
               consequently
               though
               in
               respect
               of
               the
               Plains
               ,
               adjacent
               to
               the
               feet
               of
               the
               Mountains
               ,
               their
               Altitudes
               may
               be
               equal
               ,
               yet
               in
               respect
               of
               the
               Level
               or
               Superficies
               of
               the
               Terraqueous
               Globe
               ,
               consider'd
               as
               having
               no
               Mountains
               at
               all
               but
               those
               two
               ,
               the
               height
               of
               the
               one
               may
               far
               exceed
               that
               of
               the
               other
               ;
               and
               so
               the
               Pic
               of
               Tenariff
               being
               look'd
               upon
               from
               the
               Level
               of
               the
               Sea
               ,
               may
               be
               much
               less
               high
               than
               some
               other
               Hils
               ,
               but
               may
               appear
               much
               higher
               than
               some
               other
               Hils
               ,
               which
               yet
               protuberating
               above
               the
               level
               part
               of
               some
               Country
               which
               is
               it self
               generally
               exceeding
               high
               ,
               may
               have
               
               its
               top
               more
               remote
               from
               the
               Centre
               of
               the
               Earth
               ,
               than
               that
               of
               the
               Pic
               ,
               and
               would
               appear
               higher
               than
               it
               ,
               if
               as
               well
               the
               one
               as
               the
               other
               were
               look'd
               upon
               from
               the
               same
               Superficies
               of
               the
               Sea.
               
            
             
               But
               to
               return
               to
               the
               height
               of
               the
               Atmosphere
               ;
               in
               order
               to
               the
               making
               an
               Estimate
               of
               what
               we
               have
               consider'd
               as
               to
               the
               height
               of
               Mountains
               ,
               I
               shall
               adde
               ,
               that
               though
               by
               what
               has
               been
               already
               said
               touching
               the
               height
               of
               the
               Pic
               ,
               and
               other
               Hills
               ,
               it
               appears
               ,
               that
               the
               Atmosphere
               reaches
               far
               higher
               than
               many
               learned
               men
               would
               hitherto
               allow
               ,
               yet
               we
               are
               not
               to
               think
               that
               the
               Atmosphere
               may
               not
               reach
               almost
               incomparably
               higher
               than
               the
               tops
               of
               Mountains
               .
               Nor
               do
               I
               suffer
               my self
               to
               be
               concluded
               by
               what
               many
               Comentators
               of
               Aristotle
               and
               other
               Writers
               are
               wont
               to
               teach
               touching
               the
               distinct
               narrow
               Extent
               they
               allow
               to
               that
               Sphere
               ,
               within
               whose
               Limits
               they
               would
               have
               the
               Steams
               of
               the
               Terrestrial
               Globe
               to
               produce
               Meteors
               .
               How
               far
               the
               Height
               of
               Mountains
               may
               make
               the
               Air
               at
               the
               tops
               of
               them
               inconvenient
               for
               Respiration
               ,
               shall
               be
               (
               God
               permitting
               )
               consider'd
               ,
               when
               I
               come
               to
               acquaint
               Your
               Lordship
               with
               my
               loose
               Tryals
               about
               Respiration
               .
            
          
        
         
           
             EXPERIMENT
             XXIV
             .
          
           
             Shewing
             that
             the
             Pressure
             of
             the
             Atmosphere
             may
             be
             exercis'd
             enough
             to
             keep
             up
             the
             Mercury
             in
             the
             Torricellian
             Experiment
             ,
             though
             the
             Air
             press
             upon
             it
             at
             a
             very
             small
             Orifice
             .
          
           
             BY
             a
             very
             slight
             variation
             of
             the
             foregoing
             22
             th
             Experiment
             we
             may
             both
             confirm
             one
             of
             the
             most
             important
             and
             the
             least
             likely
             Truths
             of
             the
             Hydrostaticks
             ,
             and
             remove
             an
             Objection
             ,
             which
             ,
             for
             want
             of
             the
             knowledg
             of
             this
             Truth
             ,
             is
             wont
             to
             be
             urg'd
             against
             your
             Hypothesis
             even
             by
             Learned
             men
             .
             For
             divers
             of
             these
             ,
             when
             they
             see
             the
             same
             Phaenomena
             happen
             in
             the
             Torricellian
             Experiment
             ,
             whether
             it
             be
             made
             in
             the
             open
             Air
             ,
             or
             in
             a
             
             Chamber
             ,
             are
             forward
             to
             object
             ,
             That
             if
             it
             were
             ,
             as
             we
             say
             t
             is
             ,
             the
             weight
             of
             the
             Air
             ,
             incumbent
             on
             the
             stagnant
             Mercury
             ,
             which
             keeps
             that
             suspended
             in
             the
             Tube
             from
             falling
             down
             ,
             the
             Mercury
             would
             not
             be
             sustain'd
             at
             any
             thing
             near
             the
             same
             height
             in
             the
             open
             Air
             ,
             where
             the
             Pillar
             that
             is
             suppos'd
             to
             lean
             upon
             the
             stagnant
             Mercury
             ,
             may
             reach
             up
             to
             the
             top
             of
             the
             Atmosphere
             ,
             as
             in
             a
             close
             room
             ,
             where
             they
             imagine
             that
             no
             more
             Air
             can
             press
             upon
             it
             ,
             than
             what
             reaches
             directly
             up
             to
             the
             Roof
             or
             Sealing
             .
             And
             when
             to
             this
             t
             is
             answer'd
             ,
             that
             though
             if
             a
             Room
             were
             indeed
             exactly
             clos'd
             ,
             the
             Sustentation
             of
             the
             Mercury
             ought
             to
             be
             ascrib'd
             to
             some
             other
             cause
             than
             the
             weight
             of
             the
             Imprison'd
             Air
             ,
             (
             which
             other
             Cause
             I
             have
             elsewhere
             shewn
             to
             be
             its
             Spring
             ;
             )
             yet
             in
             ordinary
             Rooms
             there
             is
             still
             a
             Communication
             between
             the
             internal
             and
             external
             Air
             ,
             either
             by
             the
             Chimney
             ,
             or
             ,
             if
             the
             Room
             have
             none
             ,
             by
             some
             Crevice
             in
             the
             Window
             ,
             or
             by
             some
             Chink
             between
             the
             Wall
             and
             the
             Door
             ,
             or
             at
             least
             by
             the
             Key-hole
             .
             And
             when
             to
             this
             t
             is
             objected
             ,
             that
             the
             Orifice
             of
             the
             Keyhole
             is
             much
             narrower
             than
             the
             Superficies
             of
             the
             stagnant
             Mercury
             ,
             and
             consequently
             ,
             though
             the
             Atmosphere
             were
             not
             reduc'd
             to
             press
             obliquely
             on
             the
             Mercury
             ,
             yet
             ,
             entring
             at
             so
             small
             an
             Orifice
             ,
             it
             could
             not
             press
             sufficiently
             upon
             it
             ;
             when
             ,
             I
             say
             ,
             in
             answer
             to
             this
             Objection
             I
             have
             alleadg'd
             that
             Hydrostatical
             Theoreme
             ,
             That
             the
             Pressure
             ,
             in
             such
             cases
             as
             ours
             ,
             is
             to
             be
             estimated
             by
             the
             heights
             of
             the
             Liquors
             and
             not
             the
             breadths
             ,
             the
             Assertion
             has
             been
             thought
             unlikely
             and
             precarious
             .
          
           
             To
             confirm
             therefore
             this
             Hydrostatical
             Truth
             ,
             one
             may
             take
             the
             bended
             Tube
             ,
             mention'd
             in
             the
             22
             th
             Experiment
             ;
             and
             inclining
             it
             till
             the
             greatest
             part
             of
             the
             Mercury
             pass
             from
             the
             shorter
             Leg
             into
             the
             longer
             ,
             the
             upper
             end
             of
             this
             shorter
             Leg
             may
             by
             the
             flame
             of
             a
             Lamp
             be
             drawn
             out
             so
             slender
             ,
             that
             the
             Orifice
             of
             it
             shall
             not
             be
             above
             an
             8
             th
             or
             10
             th
             part
             (
             not
             to
             say
             a
             much
             lesse
             )
             as
             big
             as
             't
             was
             before
             .
             For
             this
             being
             done
             ,
             and
             the
             Tube
             erected
             again
             ,
             if
             the
             tall
             Cylinder
             of
             Mercury
             be
             of
             the
             usual
             or
             former
             height
             ,
             as
             we
             have
             found
             it
             ,
             't
             will
             appear
             congruous
             to
             our
             
             Hypothesis
             ,
             that
             the
             weight
             of
             the
             external
             Air
             may
             exercise
             as
             much
             Pression
             upon
             the
             stagnant
             Mercury
             through
             a
             little
             hole
             ,
             as
             when
             all
             the
             upper
             Superficies
             of
             that
             Mercury
             was
             directly
             expos'd
             to
             it
             .
          
           
             And
             if
             one
             have
             not
             the
             conveniency
             to
             draw
             out
             the
             shorter
             Leg
             as
             is
             prescrib'd
             ,
             one
             may
             nevertheless
             make
             the
             Tryal
             ,
             by
             carefully
             stopping
             up
             the
             Orifice
             with
             a
             Cork
             and
             Cement
             ,
             leaving
             onely
             (
             or
             afterwards
             making
             )
             a
             very
             small
             hole
             for
             the
             Air
             to
             pass
             in
             and
             out
             .
             If
             I
             had
             not
             wanted
             a
             fit
             Instrument
             ,
             I
             would
             have
             tried
             to
             exemplifie
             the
             Truth
             of
             what
             has
             been
             delivered
             ,
             by
             adding
             to
             the
             Glasses
             we
             imploy'd
             to
             make
             the
             V
             th
             .
             Experiment
             ,
             such
             a
             Cover
             ,
             as
             might
             be
             cemented
             on
             to
             the
             Edge
             of
             the
             Glass
             ,
             having
             onely
             a
             very
             small
             hole
             in
             the
             midst
             ,
             at
             which
             the
             Atmosphere
             would
             be
             reduc'd
             to
             exercise
             its
             Pressure
             ;
             and
             the
             like
             Cover
             I
             would
             have
             made
             use
             of
             in
             the
             X
             th
             Experiment
             ,
             about
             the
             breaking
             of
             Glass-plates
             in
             the
             unexhausted
             Receiver
             ,
             by
             the
             bare
             Spring
             of
             the
             Air.
             
          
        
         
           
             EXPERIMENT
             XXV
             .
          
           
             Shewing
             that
             an
             Oblique
             pressure
             of
             the
             Atmosphere
             may
             suffice
             to
             keep
             up
             the
             Mercury
             at
             the
             wonted
             height
             in
             the
             Torricellian
             Experiment
             ,
             and
             that
             the
             Spring
             of
             a
             little
             included
             Air
             may
             do
             the
             same
             .
          
           
             BY
             adding
             a
             couple
             of
             little
             Circumstances
             to
             the
             Tryals
             lately
             propos'd
             ,
             we
             may
             confirm
             two
             considerable
             Articles
             of
             our
             Hypothesis
             .
             For
             1.
             if
             ,
             in
             stead
             of
             drawing
             the
             shorter
             Leg
             of
             our
             Barometrical
             Syphon
             (
             if
             I
             may
             so
             call
             it
             )
             directly
             upwards
             ,
             or
             parallel
             to
             the
             longer
             Leg
             as
             in
             the
             foregoing
             Experiment
             ,
             You
             make
             the
             slender
             part
             bend
             off
             so
             ,
             as
             that
             ,
             if
             it
             were
             continued
             ,
             it
             would
             make
             a
             right
             Angle
             with
             the
             longer
             Leg
             of
             the
             Syphon
             ,
             or
             else
             an
             acute
             Angle
             tending
             downwards
             ;
             this
             being
             done
             ,
             I
             say
             ,
             
             if
             when
             the
             Tube
             is
             erected
             the
             Mercury
             rest
             at
             its
             wonted
             station
             ,
             't
             will
             appear
             ,
             that
             the
             Pressure
             of
             the
             Atmosphere
             may
             be
             exercis'd
             upon
             it
             as
             well
             obliquely
             ,
             when
             the
             Pipe
             that
             conveyes
             it
             is
             either
             Horizontal
             ,
             or
             opens
             downwards
             .
          
           
             And
             2.
             if
             in
             stead
             of
             bending
             this
             slender
             Pipe
             ,
             one
             seal
             it
             up
             Hermetically
             ,
             the
             continuance
             of
             the
             Mercurial
             Cylinder
             at
             the
             same
             height
             will
             shew
             ,
             that
             the
             Spring
             of
             a
             very
             litle
             Air
             ,
             shut
             up
             with
             the
             Presure
             of
             the
             Atmosphere
             upon
             it
             ,
             (
             though
             no
             more
             than
             what
             the
             Air
             here
             below
             is
             ordinarily
             expos'd
             to
             by
             the
             weight
             of
             the
             incumbent
             Air
             ,
             )
             is
             able
             to
             support
             as
             tall
             a
             Cylinder
             of
             Mercury
             as
             the
             weight
             of
             the
             whole
             Atmosphere
             ,
             
               i.
               e.
            
             of
             as
             much
             of
             it
             ,
             as
             can
             come
             to
             exercise
             its
             Pressure
             against
             the
             Mercury
             .
          
           
             NB.
             If
             when
             the
             shorter
             Leg
             of
             the
             Baroscope
             is
             seal'd
             up
             ,
             you
             move
             the
             Instrument
             up
             and
             down
             ,
             the
             Mercury
             will
             vibrate
             ,
             by
             reason
             of
             the
             somewhat
             yielding
             Spring
             of
             the
             imprisoned
             Air
             ;
             but
             because
             of
             the
             resistance
             of
             the
             Spring
             ,
             the
             motion
             will
             be
             diversified
             after
             an
             odde
             and
             pretty
             manner
             :
             which
             may
             be
             easily
             perceiv'd
             by
             the
             Impression
             it
             makes
             upon
             the
             Hand
             ,
             but
             not
             so
             easily
             describ'd
             .
             And
             because
             that
             ,
             when
             the
             shorter
             Leg
             is
             drawn
             out
             slender
             enough
             ,
             after
             the
             Instrument
             is
             furnish'd
             with
             Quick-silver
             ,
             t
             is
             easie
             to
             seal
             it
             up
             with
             the
             flame
             of
             a
             Candle
             ,
             without
             the
             help
             of
             any
             Instrument
             at
             all
             ,
             I
             shall
             here
             take
             notice
             to
             Your
             Lorship
             ,
             (
             which
             I
             could
             not
             reasonably
             do
             before
             ,
             )
             that
             it
             may
             on
             some
             occasions
             be
             convenient
             to
             seal
             up
             the
             Barometer
             ,
             before
             it
             be
             transported
             ,
             and
             ,
             in
             some
             cases
             ,
             to
             incline
             the
             Tube
             beforehand
             ,
             till
             the
             Quick-silver
             have
             quite
             fill'd
             the
             longer
             Leg
             ;
             by
             this
             means
             the
             vibrations
             of
             the
             Quick-silver
             will
             be
             less
             than
             otherwise
             they
             would
             be
             ,
             and
             't
             will
             be
             no
             trouble
             at
             all
             ,
             when
             the
             Instrument
             is
             brought
             to
             the
             design'd
             place
             ,
             to
             break
             off
             the
             slender
             Apex
             of
             the
             shorter
             Leg
             ,
             and
             so
             expose
             again
             the
             Mercury
             to
             the
             Pressure
             of
             the
             Atmosphere
             .
          
           
             As
             about
             the
             former
             Experiments
             ,
             so
             about
             these
             two
             this
             Advertisement
             may
             be
             given
             ;
             viz.
             That
             the
             same
             Tryals
             ,
             for
             
             the
             main
             ,
             may
             be
             made
             without
             confining
             ones
             self
             to
             the
             propos'd
             wayes
             of
             making
             them
             .
          
           
             1.
             
             For
             the
             First
             of
             these
             new
             Tryals
             may
             be
             made
             by
             Cementing
             very
             carefully
             on
             to
             the
             Orifice
             of
             the
             shorter
             Leg
             (
             which
             need
             not
             be
             alter'd
             )
             a
             short
             Pipe
             of
             Glass
             ,
             whose
             upper
             end
             may
             be
             drawn
             out
             very
             slender
             ,
             and
             bent
             either
             Horizontally
             or
             downwards
             ;
             which
             is
             far
             easier
             to
             be
             done
             ,
             than
             to
             draw
             out
             the
             shorter
             Leg
             when
             the
             Glass
             is
             furnish'd
             with
             Mercury
             .
          
           
             2.
             
             And
             as
             for
             the
             2
             d
             Tryal
             ,
             that
             may
             be
             well
             enough
             made
             ,
             by
             carefully
             stopping
             the
             unalter'd
             Orifice
             of
             the
             shorter
             Leg
             with
             a
             good
             Cork
             ,
             and
             our
             close
             Cement
             ,
             or
             with
             the
             later
             onely
             ;
             and
             when
             you
             would
             afterwards
             use
             this
             Instrument
             as
             a
             Baroscope
             ,
             You
             need
             but
             heat
             a
             Pin
             or
             slender
             Wire
             red
             hot
             ,
             and
             so
             burn
             a
             hole
             through
             the
             Stoppel
             .
          
           
             And
             this
             Expedient
             ,
             which
             I
             could
             not
             conveniently
             advertise
             Your
             Lordship
             of
             sooner
             ,
             may
             be
             of
             Use
             when
             a
             Travailing
             Baroscope
             is
             to
             be
             often
             remov'd
             :
             because
             having
             once
             stopt
             the
             whole
             Orifice
             well
             ,
             t
             is
             far
             more
             easie
             to
             stop
             and
             open
             a
             Pin-hole
             accurately
             ,
             than
             to
             close
             and
             unstop
             the
             whole
             Orifice
             of
             the
             Tube
             .
          
           
             Note
             ,
             I
             endeavoured
             to
             confirm
             more
             than
             one
             of
             the
             foregoing
             Particulars
             by
             this
             one
             Experiment
             .
             Having
             caus'd
             a
             Portable
             Barometer
             to
             be
             made
             with
             the
             shorter
             Leg
             of
             a
             somewhat
             more
             than
             ordinary
             length
             ,
             I
             afterwards
             caus'd
             the
             upper
             part
             of
             this
             Leg
             to
             be
             drawn
             out
             very
             slender
             ,
             (
             as
             in
             this
             25
             th
             Experiment
             ;
             )
             and
             lastly
             I
             caus'd
             the
             same
             shorter
             Leg
             to
             be
             either
             about
             or
             somewhat
             above
             the
             middle
             bended
             downwards
             ,
             so
             that
             the
             small
             Orifice
             of
             the
             slender
             Apex
             pointed
             towards
             the
             Ground
             .
             This
             done
             ,
             I
             was
             to
             have
             measur'd
             the
             height
             of
             the
             suspended
             Mercury
             ,
             but
             not
             having
             a
             fit
             Ruler
             at
             hand
             ,
             I
             then
             deferr'd
             ,
             and
             afterwards
             forgot
             to
             do
             it
             ;
             but
             I
             remember
             ,
             that
             neither
             I
             ,
             nor
             some
             others
             vers'd
             in
             such
             Experiments
             ,
             to
             whom
             I
             shew'd
             it
             ,
             took
             any
             notice
             that
             the
             Mercury
             was
             less
             high
             than
             in
             ordinary
             Barometers
             ;
             whence
             't
             was
             concluded
             ,
             that
             the
             Atmosphere
             
             could
             exercise
             his
             Pressure
             not
             onely
             at
             a
             very
             small
             Orifice
             ,
             (
             which
             in
             our
             Experiment
             did
             litle
             ,
             if
             at
             all
             ,
             exceed
             a
             Pin-hole
             ,
             )
             but
             when
             the
             Air
             must
             at
             this
             little
             Orifice
             press
             upwards
             to
             be
             able
             to
             press
             upon
             the
             Surface
             of
             the
             stagnant
             Mercury
             :
          
        
         
           
             EXPERIMENT
             XXVI
             .
          
           
             About
             the
             making
             of
             a
             Baroscope
             (
             but
             of
             litle
             practical
             use
             )
             that
             serves
             but
             at
             certain
             times
             .
          
           
             TO
             shew
             some
             Ingenious
             men
             by
             a
             Medium
             ,
             that
             has
             not
             hitherto
             (
             that
             I
             know
             of
             )
             been
             made
             use
             of
             ,
             That
             the
             not
             subsiding
             of
             Quick-silver
             in
             an
             inverted
             Tube
             ,
             that
             is
             a
             little
             shorter
             than
             30
             inches
             ,
             or
             thereabouts
             ,
             does
             not
             proceed
             from
             such
             a
             
               fuga
               Vacui
            
             as
             the
             Schools
             ascribe
             to
             Nature
             ,
             but
             from
             the
             Gravity
             of
             the
             external
             Air
             ,
             I
             devised
             the
             following
             Experiment
             .
          
           
             Having
             made
             choice
             of
             a
             time
             ,
             when
             it
             appear'd
             by
             a
             good
             Baroscope
             ,
             (
             which
             I
             had
             frequently
             consulted
             for
             that
             purpose
             ,
             )
             that
             the
             Atmosphere
             was
             considerably
             heavy
             ,
             I
             caus'd
             Galspipe
             ,
             Hermetically
             seal'd
             at
             one
             end
             ,
             and
             in
             length
             about
             2
             foot
             and
             a
             half
             ,
             to
             be
             fill'd
             with
             Quick-silver
             ,
             save
             a
             very
             litle
             wherein
             some
             drops
             of
             Water
             were
             put
             ,
             that
             we
             might
             the
             better
             discern
             the
             Bubbles
             ,
             if
             any
             should
             be
             left
             after
             the
             inversion
             of
             the
             Tube
             into
             an
             open
             Glass
             with
             stagnant
             Mercury
             in
             it
             .
             Having
             by
             this
             means
             (
             though
             not
             without
             difficulty
             )
             freed
             the
             Tube
             from
             bubbles
             ,
             we
             so
             order'd
             the
             matter
             ,
             that
             the
             Quick-silver
             and
             the
             litle
             water
             that
             was
             about
             it
             ,
             fill'd
             the
             Tube
             exactly
             ,
             without
             leaving
             any
             interval
             that
             we
             could
             discern
             at
             the
             top
             ,
             and
             yet
             the
             Mercurial
             Cylinder
             was
             but
             very
             little
             higher
             than
             that
             of
             our
             Baroscope
             was
             at
             that
             time
             .
          
           
             This
             done
             ,
             the
             newly
             fill'd
             Pipe
             was
             left
             erected
             in
             a
             quiet
             place
             ,
             where
             the
             Liquors
             retain'd
             their
             former
             height
             for
             divers
             dayes
             .
             But
             though
             an
             ordinary
             School-Philosopher
             would
             confidently
             
             have
             attributed
             this
             sustation
             of
             so
             heavy
             a
             Body
             to
             Nature's
             fear
             of
             admitting
             a
             Vacuum
             ,
             yet
             it
             seems
             ,
             that
             either
             she
             is
             not
             alwayes
             equally
             subject
             to
             that
             fear
             ,
             or
             some
             other
             cause
             of
             the
             Phaenomenon
             must
             be
             assign'd
             ;
             for
             when
             (
             a
             pretty
             while
             after
             )
             I
             had
             observ'd
             by
             the
             Baroscope
             ,
             that
             the
             Atmosphere
             was
             grown
             much
             lighter
             than
             before
             ,
             repairing
             to
             my
             short
             Tube
             ,
             I
             found
             that
             according
             to
             my
             expectation
             the
             Quick-silver
             was
             not
             inconsiderably
             subsided
             ,
             and
             had
             left
             a
             Cavity
             at
             the
             top
             ,
             which
             afterwards
             grew
             lesser
             ,
             according
             as
             the
             Atmosphere
             grew
             heavier
             .
          
           
             NB.
             1.
             
             The
             Tube
             imployed
             about
             this
             Experiment
             ,
             may
             be
             brought
             to
             the
             requisite
             shortness
             ,
             either
             by
             wearing
             off
             a
             little
             of
             the
             Glass
             at
             the
             Orifice
             of
             it
             ,
             or
             by
             increasing
             the
             height
             of
             the
             stagnant
             Mercury
             ,
             into
             which
             it
             hath
             been
             inverted
             .
          
           
             2.
             
             When
             the
             Quick
             silver
             in
             our
             short
             Tube
             was
             much
             subsided
             ,
             there
             appeared
             in
             the
             Water
             that
             swam
             upon
             it
             a
             litle
             Bubble
             ,
             about
             the
             bigness
             of
             a
             small
             Pins
             head
             ,
             but
             ,
             considering
             how
             careful
             we
             had
             been
             to
             free
             the
             Tube
             from
             bubbles
             before
             we
             set
             it
             to
             rest
             ,
             it
             may
             very
             well
             be
             ,
             that
             this
             so
             small
             a
             Bubble
             was
             not
             produc'd
             till
             after
             the
             subsiding
             of
             the
             Quick-silver
             ,
             whereupon
             the
             Aerial
             Particles
             in
             the
             Water
             became
             less
             compress'd
             than
             before
             ;
             not
             to
             mention
             that
             the
             Bubble
             (
             such
             as
             it
             was
             )
             appear'd
             very
             much
             greater
             than
             it
             would
             have
             done
             ,
             if
             the
             Pressure
             of
             the
             Atmosphere
             had
             not
             been
             kept
             from
             it
             by
             the
             weight
             of
             the
             subjacent
             pillar
             of
             Mercury
             .
          
        
         
           
             EXPERIMENT
             XXVII
             .
          
           
             About
             the
             Ascension
             of
             Liquors
             in
             very
             slender
             Pipes
             in
             an
             Exhausted
             Receiver
             .
          
           
             VVHat
             I
             related
             to
             Your
             Lordship
             in
             the
             35
             th
             of
             the
             publish'd
             Experiments
             ,
             (
             pag.
             138.
             )
             about
             the
             seemingly
             spontaneous
             Ascension
             of
             Water
             in
             slender
             Pipes
             ,
             has
             occasion'd
             the
             
             making
             of
             many
             Tryals
             by
             the
             Curious
             ,
             whereby
             that
             Experiment
             has
             been
             not
             a
             little
             diversify'd
             ;
             but
             because
             among
             those
             I
             have
             yet
             heard
             of
             none
             have
             been
             made
             in
             our
             Engine
             ,
             it
             may
             not
             be
             amiss
             to
             adde
             the
             following
             Tryal
             ,
             which
             may
             be
             of
             use
             in
             the
             Examen
             of
             one
             or
             two
             of
             the
             chief
             Conjectures
             that
             have
             hitherto
             been
             propos'd
             about
             the
             cause
             of
             that
             odde
             phaenomenon
             .
          
           
             We
             ting'd
             some
             spirit
             of
             Wine
             with
             Cocheneel
             ,
             which
             being
             put
             into
             the
             Receiver
             ,
             and
             the
             Air
             withdrawn
             ,
             did
             exceedingly
             bubble
             for
             a
             pretty
             while
             .
             Then
             little
             hollow
             Pipes
             of
             differing
             Sizes
             being
             put
             into
             it
             ,
             the
             red
             Liquor
             ascended
             higher
             in
             the
             slenderer
             than
             the
             others
             ,
             but
             upon
             the
             withdrawing
             of
             the
             Air
             there
             scarce
             appear'd
             any
             sensible
             difference
             in
             the
             heights
             of
             the
             Liquor
             ,
             nor
             yet
             upon
             the
             letting
             it
             in
             again
             .
          
           
             Afterwards
             two
             such
             Pipes
             of
             differing
             Sizes
             ,
             being
             fasten'd
             together
             (
             at
             a
             distance
             )
             with
             Cement
             ,
             were
             let
             down
             into
             the
             same
             spirit
             of
             Wine
             when
             the
             Receiver
             was
             well
             exhausted
             ,
             notwithstanding
             which
             the
             Liquor
             ascended
             in
             them
             ,
             for
             ought
             we
             could
             plainly
             see
             ,
             after
             the
             ordinary
             manner
             ;
             onely
             when
             the
             Air
             was
             let
             in
             again
             ,
             there
             seem'd
             to
             be
             some
             little
             (
             and
             but
             very
             litle
             )
             rising
             at
             least
             in
             one
             of
             the
             Pipes
             .
             In
             this
             Tryal
             this
             Phaenomenon
             was
             noted
             :
             That
             though
             there
             appear'd
             no
             Bubbles
             at
             all
             in
             the
             vessel'd
             spirit
             of
             Wine
             ,
             (
             notwithstanding
             that
             we
             continued
             to
             pump
             ,
             )
             yet
             there
             did
             for
             a
             pretty
             while
             arise
             bubbles
             in
             that
             part
             of
             the
             Liquor
             that
             was
             got
             into
             the
             slender
             Pipes
             ;
             which
             I
             guess'd
             to
             proceed
             from
             the
             sustentation
             (
             in
             part
             )
             of
             the
             spirit
             of
             Wine
             ,
             made
             by
             the
             inside
             of
             the
             Pipe
             whereto
             it
             adher'd
             .
          
        
         
           
           
             EXPERIMENT
             XXVIII
             .
          
           
             About
             the
             great
             and
             seemingly
             spontaneous
             Ascension
             of
             Water
             in
             a
             Pipe
             fill'd
             with
             a
             compact
             body
             ,
             whose
             Particles
             are
             thought
             incapable
             of
             imbibing
             it
             .
          
           
             VPon
             occasion
             of
             the
             (
             seemingly
             )
             spontaneous
             Ascension
             of
             Water
             in
             slender
             Pipes
             of
             Glass
             ,
             I
             consider'd
             that
             't
             would
             be
             easie
             by
             another
             way
             to
             make
             it
             rise
             to
             a
             far
             Greater
             height
             than
             hitherto
             had
             been
             done
             ;
             for
             since
             we
             had
             found
             by
             Observation
             that
             ,
             
               caeteris
               paribus
            
             ,
             the
             slenderer
             the
             little
             Pipes
             were
             that
             we
             imployed
             ,
             the
             higher
             the
             Liquor
             would
             rise
             in
             them
             ;
             and
             since
             the
             Hydrostaticks
             had
             taught
             us
             ,
             that
             often
             times
             even
             in
             very
             crooked
             Pipes
             Water
             would
             be
             made
             to
             ascend
             by
             the
             same
             wayes
             (
             of
             raising
             it
             )
             to
             the
             same
             perpendicular
             height
             (
             or
             thereabouts
             )
             as
             in
             straight
             ones
             ;
             I
             thought
             ,
             that
             I
             might
             well
             substitute
             a
             Powder
             ,
             consisting
             of
             solid
             Corpuscles
             heap'd
             upon
             one
             another
             ,
             and
             included
             in
             a
             Glass-Cane
             in
             stead
             of
             the
             litle
             Pipes
             I
             had
             hitherto
             used
             .
             For
             I
             consider'd
             the
             litle
             intervals
             ,
             that
             would
             necessarily
             be
             left
             between
             these
             differingly
             shap'd
             and
             confusedly
             plac'd
             Corpuscles
             ,
             would
             allow
             passage
             to
             the
             Water
             as
             did
             the
             Cavities
             of
             the
             little
             Pipes
             ,
             and
             yet
             would
             in
             many
             places
             be
             straiter
             than
             the
             slenderest
             Pipes
             I
             had
             us'd
             .
             And
             though
             beaten
             Glass
             ,
             or
             fine
             Sand
             ,
             &c.
             might
             have
             been
             imployed
             about
             this
             Experiment
             ,
             yet
             I
             judg'd
             it
             far
             more
             convenient
             to
             make
             use
             of
             some
             Metalline
             Calx
             ,
             because
             the
             Operation
             of
             the
             Fire
             ,
             making
             a
             more
             exquisite
             Comminution
             of
             Solid
             bodies
             than
             our
             Pestles
             are
             wont
             to
             do
             ,
             is
             fit
             to
             supply
             us
             with
             exceeding
             minute
             Granes
             ,
             that
             intercept
             proportionable
             Cavities
             between
             them
             .
          
           
             Upon
             this
             Consideration
             therefore
             (
             besides
             others
             to
             be
             hereafter
             hinted
             )
             I
             took
             a
             strait
             pipe
             of
             Glass
             ,
             open
             at
             both
             ends
             ,
             and
             of
             a
             moderate
             wideness
             ,
             (
             for
             it
             need
             not
             be
             very
             slender
             ,
             )
             and
             having
             tyed
             a
             Linnen-rag
             to
             one
             end
             of
             it
             ,
             that
             the
             Water
             might
             
             have
             free
             passage
             in
             ,
             and
             the
             Powder
             not
             be
             able
             to
             fall
             out
             ,
             we
             carefully
             and
             as
             exactly
             as
             we
             could
             ,
             fill'd
             the
             Cavity
             with
             Minium
             ,
             (
             which
             is
             Lead
             calcin'd
             ,
             without
             addition
             ,
             to
             Redness
             ;
             )
             and
             then
             having
             erected
             the
             Tube
             ,
             so
             that
             the
             bottom
             of
             it
             rested
             upon
             that
             of
             a
             somewhat
             shallow
             and
             open
             mouth'd
             Glass
             ,
             containing
             Water
             enough
             to
             swim
             an
             Inch
             or
             two
             above
             the
             bottom
             of
             the
             Tube
             ;
             
             into
             whose
             cavity
             it
             did
             ,
             as
             I
             expected
             ,
             insinuate
             it self
             by
             degrees
             ,
             as
             appear'd
             by
             a
             litle
             change
             of
             colour
             in
             that
             part
             of
             the
             Minium
             which
             it
             reacht
             ,
             till
             (
             the
             open
             Glass
             being
             from
             time
             to
             time
             supplied
             with
             fresh
             liquor
             )
             it
             attain'd
             to
             the
             height
             of
             about
             30
             inches
             .
             And
             then
             ,
             our
             Society
             expressing
             a
             Curiosity
             to
             see
             it
             ,
             and
             have
             it
             plac'd
             among
             better
             things
             ,
             I
             was
             hinder'd
             from
             making
             any
             further
             Observations
             with
             that
             particular
             Glass
             .
          
           
             Wherefore
             taking
             afterwards
             another
             Tube
             ,
             and
             some
             Minimum
             carefully
             prepared
             ,
             I
             prosecuted
             the
             Experiment
             so
             as
             to
             make
             the
             Water
             rise
             in
             the
             Pipe
             about
             40
             inches
             above
             the
             surface
             of
             the
             stagnant
             Water
             ;
             and
             I
             guess'd
             it
             had
             risen
             higher
             ,
             but
             ,
             by
             reason
             that
             at
             the
             upper
             part
             of
             the
             Minimum
             the
             difference
             of
             colour
             was
             so
             small
             ,
             as
             not
             to
             be
             easily
             distinguishable
             with
             certainty
             ,
             I
             forbore
             to
             allow
             a
             greater
             height
             to
             the
             Ascension
             of
             the
             Water
             :
             nor
             could
             I
             ,
             where
             I
             then
             was
             ,
             much
             promote
             the
             Experiment
             ,
             for
             want
             of
             such
             Accommodations
             as
             I
             desir'd
             ;
             but
             about
             the
             Experiment
             ,
             as
             I
             try'd
             it
             ,
             I
             shall
             take
             notice
             of
             the
             following
             particulars
             .
          
           
             I
             tryed
             some
             other
             Powders
             besides
             red
             Lead
             ,
             (
             as
             beaten
             Glass
             ,
             pieces
             of
             fine
             Spunge
             ,
             Putty
             ,
             &c.
             )
             but
             did
             not
             find
             any
             of
             them
             do
             so
             well
             ;
             which
             success
             was
             yet
             perhaps
             but
             accidental
             ,
             and
             therefore
             the
             Tryal
             may
             be
             repeated
             ,
             especially
             with
             Putty
             ,
             because
             that
             being
             a
             Metalline
             Calx
             as
             well
             as
             Minium
             ,
             consists
             of
             very
             small
             Grains
             ,
             and
             by
             reason
             of
             its
             Great
             whiteness
             receives
             a
             Greater
             change
             of
             colour
             by
             wetting
             than
             Minium
             does
             ;
             in
             which
             ,
             especially
             if
             it
             be
             very
             fine
             ,
             the
             discoloration
             that
             Water
             makes
             toward
             the
             upper
             part
             of
             the
             Tube
             ,
             is
             sometimes
             not
             so
             easie
             to
             be
             clearly
             discern'd
             .
          
           
           
             2.
             
             I
             did
             indeed
             endeavour
             to
             remedy
             this
             inconvenience
             ,
             by
             using
             ,
             in
             stead
             of
             meer
             Water
             ,
             tincted
             Liquors
             ,
             as
             Ink
             ,
             tincture
             of
             Safron
             ,
             &c.
             but
             they
             seem'd
             not
             to
             rise
             near
             so
             high
             as
             Water
             alone
             ,
             as
             if
             the
             dissolv'd
             ingredients
             did
             by
             degrees
             choak
             the
             pores
             of
             the
             Minium
             .
          
           
             3.
             
             To
             have
             the
             Grains
             of
             our
             Powder
             more
             minute
             and
             the
             smaller
             intervals
             between
             them
             ,
             I
             chose
             not
             onely
             to
             use
             the
             finest
             sort
             of
             Minium
             I
             could
             procure
             ,
             but
             also
             to
             sift
             it
             through
             a
             very
             fine
             Searce
             ,
             and
             to
             put
             it
             but
             by
             litle
             and
             litle
             into
             the
             Tube
             ,
             that
             by
             ramming
             it
             from
             time
             to
             time
             it
             might
             be
             made
             to
             lie
             the
             closer
             ;
             which
             Expedients
             succeeded
             not
             ill
             .
          
           
             4.
             
             It
             seem'd
             by
             a
             Tryal
             or
             two
             (
             for
             I
             am
             not
             sure
             the
             observation
             will
             alwayes
             hold
             ,
             )
             that
             if
             the
             Tube
             were
             very
             slender
             ,
             (
             as
             about
             the
             bigness
             of
             a
             Swans
             quill
             ,
             )
             the
             Experiment
             succeeded
             not
             well
             .
          
           
             5.
             
             It
             may
             be
             worth
             while
             to
             observe
             in
             what
             times
             the
             Water
             ascends
             to
             such
             and
             such
             heights
             ;
             for
             at
             the
             beginning
             t
             will
             ascend
             much
             faster
             then
             afterwards
             ,
             and
             sometimes
             t
             will
             continue
             rising
             24
             or
             30
             hours
             ,
             and
             sometimes
             perhaps
             much
             longer
             .
          
           
             6.
             
             One
             of
             the
             scopes
             I
             propos'd
             to
             my self
             in
             this
             Experiment
             was
             to
             discover
             a
             mistake
             in
             the
             Explication
             that
             some
             Learned
             modern
             Writers
             have
             given
             us
             of
             the
             cause
             of
             Filtration
             ;
             for
             whereas
             they
             teach
             that
             the
             parts
             of
             Filtre
             that
             touch
             the
             Water
             ,
             being
             swell'd
             by
             the
             ingress
             of
             it
             to
             their
             pores
             ,
             are
             thereby
             made
             to
             lift
             up
             the
             Water
             ,
             till
             it
             touch
             the
             superiour
             parts
             of
             the
             Filtre
             that
             are
             almost
             contiguous
             to
             them
             ;
             by
             which
             means
             these
             being
             also
             wetted
             ,
             and
             swell'd
             ,
             raise
             the
             Water
             to
             the
             other
             neighbouring
             parts
             of
             the
             Filtre
             ,
             till
             it
             have
             reacht
             to
             the
             top
             of
             it
             ,
             whence
             it
             s
             own
             Gravity
             will
             make
             it
             descend
             .
             But
             in
             our
             case
             we
             have
             a
             Filtre
             made
             of
             solid
             Metalline
             Corpuscles
             ,
             where
             t
             will
             be
             very
             hard
             to
             shew
             that
             any
             such
             intumescence
             is
             produc'd
             ,
             as
             the
             recited
             Explication
             requires
             .
          
           
             7.
             
             Water
             ascends
             so
             few
             inches
             even
             in
             very
             slender
             Pipes
             ,
             as
             to
             seem
             much
             to
             favour
             their
             Judgment
             ,
             who
             dissallow
             the
             
             conjecture
             lately
             entertain'd
             by
             some
             ingenious
             men
             ,
             (
             particularly
             M
             r
             H.
             )
             about
             the
             raising
             of
             the
             Sap
             in
             Trees
             after
             the
             like
             manner
             that
             Water
             is
             raised
             in
             slender
             Pipes
             ;
             but
             without
             fully
             delivering
             yet
             my
             thoughts
             of
             that
             Speculation
             ,
             I
             may
             take
             notice
             ,
             that
             in
             the
             last
             Tryal
             above
             recited
             ,
             I
             made
             Water
             to
             ascend
             near
             ,
             if
             not
             above
             ,
             3
             foot
             ½
             and
             if
             by
             so
             sleight
             an
             Expedient
             ,
             Water
             may
             be
             made
             to
             rise
             as
             high
             as
             is
             necessary
             for
             the
             Nutrition
             of
             some
             thousands
             of
             Plants
             ,
             (
             for
             such
             a
             number
             there
             is
             ,
             that
             exceed
             not
             3
             foot
             1
             /
             2
             in
             height
             ,
             )
             one
             may
             without
             absurdity
             ask
             ,
             why
             t
             is
             not
             possible
             that
             Nature
             ,
             or
             rather
             the
             most
             wise
             Author
             of
             it
             ,
             may
             have
             made
             such
             Contrivances
             in
             Plants
             ,
             as
             to
             make
             Liquors
             ascend
             in
             them
             to
             the
             Tops
             of
             the
             tallest
             Trees
             ;
             especially
             since
             ,
             besides
             divers
             things
             that
             we
             may
             already
             suspect
             ,
             (
             as
             Heat
             ,
             and
             something
             equivalent
             to
             well
             plac'd
             Valves
             ,
             )
             many
             others
             ,
             that
             perhaps
             are
             not
             yet
             dreamt
             of
             ,
             may
             probably
             concur
             to
             the
             Effect
             .
          
           
             8.
             
             As
             I
             formerly
             made
             ,
             by
             bending
             the
             slender
             Pipes
             we
             have
             been
             talking
             of
             ,
             short
             Syphons
             through
             which
             the
             Water
             runs
             ,
             without
             being
             at
             first
             assisted
             by
             Suction
             ,
             so
             I
             thought
             fit
             to
             try
             ,
             whether
             I
             could
             not
             in
             larger
             Pipes
             ,
             by
             the
             help
             of
             Minium
             ,
             make
             much
             longer
             Syphons
             .
             But
             though
             when
             the
             Orifices
             were
             turn'd
             upwards
             ,
             fine
             Minium
             were
             ramm'd
             into
             both
             the
             Legs
             ,
             and
             the
             Orifices
             were
             both
             of
             them
             clos'd
             ,
             yet
             when
             they
             came
             to
             be
             again
             turn'd
             downwards
             ,
             the
             weight
             of
             the
             Minium
             would
             somewhere
             or
             other
             (
             and
             for
             the
             most
             part
             at
             or
             near
             the
             flexure
             )
             make
             some
             such
             chink
             or
             discontinuation
             ,
             as
             to
             hinder
             the
             farther
             progress
             of
             the
             Water
             .
             Which
             impediment
             ,
             though
             I
             judg'd
             it
             superable
             enough
             ,
             (
             especially
             by
             making
             at
             the
             Flexure
             a
             little
             Pipe
             or
             Socket
             ,
             by
             which
             both
             Legs
             might
             be
             closely
             fill'd
             )
             yet
             for
             want
             of
             Accommodations
             and
             leisure
             it
             was
             left
             unsurmounted
             .
             Upon
             which
             account
             also
             I
             did
             not
             satisfie
             my self
             about
             the
             success
             of
             some
             former
             Tryals
             ,
             as
             of
             the
             Ascension
             of
             Water
             into
             pieces
             of
             Wood
             of
             differing
             sorts
             ,
             the
             operation
             of
             the
             Vicissitudes
             of
             the
             Suns
             beams
             ,
             and
             the
             absence
             of
             them
             upon
             liquors
             ascending
             in
             Tubes
             fill'd
             with
             Minium
             ,
             &c.
             
          
           
           
             9.
             
             Whether
             the
             Pressure
             of
             the
             outward
             Air
             be
             the
             cause
             of
             the
             Ascension
             of
             Liquors
             in
             our
             Tubes
             furnisht
             with
             Minium
             ,
             is
             a
             Probleme
             ,
             in
             order
             to
             whose
             Solution
             I
             could
             acquaint
             Your
             Lordship
             with
             a
             Contrivance
             ,
             wherewith
             to
             make
             some
             Tryals
             in
             our
             Engine
             .
             But
             since
             it
             can
             scarce
             be
             well
             describ'd
             without
             many
             words
             ,
             unless
             You
             express
             a
             particular
             Curiosity
             to
             know
             it
             ,
             I
             shall
             not
             trouble
             You
             with
             it
             :
             and
             the
             rather
             ,
             because
             the
             best
             way
             I
             know
             of
             examining
             this
             difficulty
             belongs
             to
             the
             2
             d
             part
             of
             this
             Continuation
             ,
             where
             mention
             is
             made
             of
             an
             attempt
             about
             it
             ,
             which
             did
             not
             ,
             I
             confess
             ,
             displease
             me
             .
          
        
         
           
             EXPERIMENT
             XXIX
             .
          
           
             Of
             the
             seemingly
             spontaneous
             Ascension
             of
             Salts
             along
             the
             sides
             of
             Glasses
             ,
             with
             a
             conjecture
             at
             the
             Cause
             of
             it
             .
          
           
             TO
             the
             same
             Cause
             (
             or
             the
             like
             )
             with
             that
             of
             the
             Ascension
             of
             Water
             in
             slender
             Pipes
             may
             be
             probably
             referr'd
             an
             odde
             Phaenomenon
             ,
             which
             though
             I
             remember
             not
             to
             have
             been
             mentioned
             by
             any
             Chymical
             or
             other
             Writer
             ,
             I
             have
             not
             unfrequently
             observed
             as
             well
             by
             chance
             as
             in
             Tryals
             purposely
             made
             to
             satisfie
             my self
             and
             others
             about
             the
             truth
             of
             it
             .
          
           
             The
             Phaenomenon
             ,
             in
             short
             ,
             was
             this
             .
             That
             having
             in
             wide-mouth'd
             Glasses
             (
             which
             should
             not
             be
             very
             deep
             )
             expos'd
             to
             the
             Air
             a
             strong
             Solution
             of
             common
             Sea-salt
             or
             of
             Vitriol
             ,
             which
             reacht
             not
             by
             some
             inches
             to
             the
             top
             of
             the
             Glass
             ;
             and
             having
             suffered
             much
             of
             the
             aqueous
             part
             to
             exhale
             away
             very
             slowly
             ,
             the
             coagulated
             Salt
             would
             at
             length
             appear
             to
             have
             lin'd
             the
             inside
             of
             the
             Glass
             ,
             and
             to
             have
             ascended
             much
             higher
             ,
             not
             onely
             than
             the
             place
             where
             the
             surface
             of
             the
             remaining
             Water
             then
             rested
             at
             ,
             but
             than
             the
             place
             to
             which
             the
             Liquor
             reacht
             when
             't
             was
             first
             poured
             in
             .
             And
             if
             the
             Experiment
             were
             continued
             long
             enough
             ,
             I
             sometimes
             observed
             this
             Ascension
             of
             the
             Salt
             to
             amount
             to
             
             some
             inches
             ,
             and
             that
             the
             salt
             did
             not
             onely
             line
             the
             inside
             of
             the
             Glass
             ,
             but
             ,
             getting
             over
             the
             brim
             of
             it
             ,
             cover'd
             the
             outside
             of
             it
             with
             a
             Saline
             Crust
             :
             which
             made
             them
             that
             saw
             how
             litle
             liquor
             remain'd
             in
             the
             Glass
             ,
             admire
             how
             it
             could
             possibly
             get
             thither
             .
          
           
             And
             though
             I
             have
             mentioned
             but
             the
             Solution
             of
             Vitriol
             and
             Sea-salt
             ,
             because
             they
             are
             much
             easier
             than
             others
             to
             be
             procur'd
             ,
             and
             yet
             the
             Experiment
             succeeds
             better
             in
             Them
             than
             in
             some
             other
             far
             less
             parable
             Salts
             ;
             yet
             they
             are
             not
             the
             onely
             ones
             by
             whose
             Solutions
             the
             recited
             Phaenomenon
             may
             be
             Exhibited
             .
          
           
             As
             for
             the
             Cause
             of
             this
             odd
             Effect
             ,
             though
             I
             shall
             not
             propose
             any
             thing
             about
             it
             with
             Confidence
             ,
             till
             I
             have
             further
             inquired
             into
             it
             ,
             and
             especially
             till
             I
             have
             tryed
             whether
             the
             Phaenomenon
             may
             be
             produced
             in
             an
             Exhausted
             Receiver
             ;
             yet
             ,
             by
             what
             I
             have
             hitherto
             observed
             ,
             I
             am
             inclin'd
             to
             conjecture
             ,
             that
             it
             may
             be
             referr'd
             to
             such
             a
             cause
             as
             that
             of
             the
             Ascension
             of
             Liquors
             in
             Pipes
             after
             some
             such
             manner
             as
             this
             .
          
           
             First
             ,
             I
             observed
             ,
             that
             in
             Water
             and
             Aqueous
             liquors
             ,
             that
             part
             of
             the
             Surface
             which
             is
             next
             the
             sides
             of
             the
             Glass
             ,
             is
             (
             whatever
             the
             reason
             of
             it
             be
             )
             sensibly
             more
             elevated
             than
             the
             rest
             of
             the
             Superficies
             ;
             and
             if
             very
             litle
             clippings
             of
             Straw
             or
             other
             such
             minute
             and
             light
             bodies
             ,
             floating
             upon
             the
             Water
             ,
             chance
             to
             approach
             near
             enough
             to
             the
             sides
             of
             the
             Glass
             ,
             they
             will
             be
             apt
             (
             which
             one
             would
             not
             expect
             )
             to
             run
             up
             as
             t
             were
             this
             ascent
             of
             Water
             ,
             and
             rest
             against
             the
             sides
             of
             the
             Glass
             .
          
           
             Next
             we
             may
             take
             notice
             with
             the
             Salt-boylers
             and
             Chymists
             ,
             that
             Sea-salt
             is
             usually
             wont
             to
             coagulate
             at
             the
             top
             of
             the
             Water
             in
             small
             and
             oblong
             Corpuscles
             ,
             so
             that
             as
             to
             these
             t
             is
             easie
             to
             conceive
             ,
             to
             them
             that
             have
             considered
             the
             first
             Observation
             ,
             how
             numbers
             of
             them
             may
             fasten
             themselves
             round
             about
             to
             the
             inside
             of
             the
             Glass
             .
             And
             besides
             Sea-salt
             ,
             I
             have
             found
             by
             tryal
             divers
             others
             ,
             
               if
               their
               Solutions
               be
               slowly
               enough
               evaporated
               ,
            
             that
             will
             ,
             whilst
             yet
             there
             remains
             a
             good
             proportion
             of
             Liquor
             ,
             afford
             Saline
             Concretions
             at
             the
             top
             of
             the
             Water
             .
             And
             the
             fastning
             of
             Saline
             particles
             to
             the
             sides
             of
             the
             Glass
             may
             perhaps
             be
             promoted
             
             by
             the
             Coldness
             that
             may
             be
             communicated
             to
             the
             Corpuscles
             contiguous
             to
             the
             Glass
             ,
             by
             reason
             of
             the
             coldness
             which
             the
             Glass
             may
             be
             suspected
             to
             have
             ,
             upon
             the
             score
             of
             its
             Density
             ,
             in
             comparison
             of
             Water
             .
             But
             to
             proceed
             :
             I
             consider
             ,
             that
             by
             the
             Evaporation
             of
             the
             aqueous
             parts
             of
             the
             Solution
             ,
             the
             surface
             of
             the
             remaining
             liquor
             must
             necessarily
             subside
             ,
             and
             those
             Saline
             particles
             ,
             that
             were
             contiguous
             to
             the
             inside
             of
             the
             Glass
             and
             the
             more
             elevated
             part
             of
             the
             Water
             ,
             having
             no
             longer
             enough
             of
             Liquor
             to
             keep
             them
             dissolv'd
             ,
             will
             be
             apt
             to
             remain
             sticking
             to
             the
             sides
             of
             the
             Glass
             ,
             and
             upon
             the
             least
             farther
             Evaporation
             of
             the
             Water
             will
             be
             a
             litle
             higher
             than
             the
             greater
             part
             of
             the
             Superficies
             of
             that
             Liquor
             ;
             by
             which
             means
             it
             will
             come
             to
             pass
             ,
             that
             ,
             by
             reason
             of
             the
             litle
             inequalities
             that
             will
             be
             on
             the
             internal
             surface
             of
             the
             adhering
             Corpuscles
             of
             the
             Salt
             ,
             and
             perhaps
             also
             on
             the
             internal
             Superficies
             of
             the
             Glass
             ,
             there
             will
             be
             intercepted
             between
             the
             Salt
             and
             the
             Glass
             litle
             Cavities
             ,
             into
             which
             the
             Water
             contiguous
             to
             the
             bottom
             will
             ascend
             or
             be
             impell'd
             upon
             such
             an
             account
             as
             that
             ,
             whereon
             t
             is
             rais'd
             in
             slender
             Pipes
             .
             And
             when
             the
             Liquor
             is
             thus
             got
             to
             the
             top
             of
             the
             Salt
             ,
             and
             comes
             to
             be
             exposed
             to
             the
             Air
             ,
             the
             Saline
             part
             may
             ,
             by
             the
             evaporation
             of
             the
             Aqueous
             ,
             be
             brought
             to
             coagulate
             there
             ,
             and
             consequently
             to
             increase
             the
             height
             of
             the
             Saline
             filme
             ,
             (
             if
             I
             may
             so
             call
             it
             ;
             )
             which
             by
             the
             like
             means
             may
             be
             at
             length
             brought
             to
             reach
             to
             the
             very
             top
             of
             the
             Glass
             ,
             whence
             it
             may
             easily
             be
             brought
             over
             to
             the
             outside
             of
             the
             vessel
             ,
             where
             the
             natural
             weight
             of
             the
             Solution
             will
             facilitate
             its
             progress
             downwards
             ;
             and
             the
             skin
             of
             Salt
             ,
             together
             with
             the
             contiguous
             surface
             of
             the
             Glass
             ,
             may
             (
             at
             length
             )
             constitute
             a
             kind
             of
             Syphon
             .
          
           
             To
             this
             Explication
             it
             agrees
             well
             ,
             that
             I
             have
             usually
             observed
             the
             Saline
             filme
             hitherto
             mentioned
             to
             be
             with
             great
             ease
             separable
             from
             the
             Glass
             in
             large
             Fleaks
             ;
             which
             argues
             ,
             that
             they
             did
             not
             stick
             close
             to
             one
             another
             except
             in
             some
             few
             places
             ,
             but
             had
             a
             thin
             Cavity
             intercepted
             between
             them
             ,
             through
             which
             the
             water
             might
             ascend
             .
          
           
           
             Nor
             is
             it
             repugnant
             to
             this
             Explication
             ,
             that
             in
             case
             the
             Water
             ascended
             ,
             it
             should
             ,
             as
             it
             seems
             ,
             dissolve
             the
             Salt.
             For
             the
             Liquor
             being
             already
             upon
             the
             point
             of
             Concretion
             ,
             is
             so
             glutted
             with
             Salt
             ,
             that
             it
             can
             dissolve
             no
             more
             .
             Whence
             we
             may
             also
             render
             a
             reason
             ,
             why
             ,
             when
             the
             Saline
             filme
             chances
             to
             reach
             to
             the
             outside
             of
             the
             Glass
             ,
             the
             Liquor
             (
             divers
             times
             )
             does
             not
             run
             down
             to
             the
             bottom
             ,
             but
             is
             coagulated
             by
             the
             way
             .
             And
             I
             have
             also
             had
             a
             suspicion
             ,
             (
             though
             I
             could
             not
             seasonably
             take
             notice
             of
             it
             before
             now
             ,
             )
             that
             when
             the
             Concretion
             is
             once
             begun
             ,
             the
             Film
             may
             be
             raised
             and
             propagated
             ,
             not
             onely
             by
             the
             motion
             of
             the
             Liquor
             between
             the
             inside
             of
             it
             and
             the
             Glass
             ,
             but
             by
             the
             same
             Liquor
             's
             insinuating
             it self
             on
             the
             outside
             of
             the
             Film
             into
             the
             small
             Chinks
             and
             Crevises
             ,
             intercepted
             between
             the
             Saline
             Corpuscles
             ,
             as
             Ink
             (
             especially
             if
             somewhat
             thin
             )
             rises
             into
             the
             Slit
             ,
             and
             along
             the
             sides
             of
             the
             Nib
             of
             a
             Pen
             ,
             though
             nothing
             but
             its
             very
             point
             be
             dipt
             in
             the
             surface
             of
             the
             liquor
             .
             And
             by
             this
             means
             the
             impregnated
             Solution
             may
             as
             it
             were
             climb
             up
             to
             the
             top
             of
             the
             saline
             Concretion
             ,
             and
             by
             coagulating
             there
             adde
             to
             its
             height
             .
          
           
             Some
             other
             Circumstances
             I
             have
             noted
             of
             our
             Phaenomenon
             ,
             that
             agree
             with
             the
             propos'd
             Explication
             ,
             but
             perhaps
             it
             would
             not
             be
             worth
             while
             to
             spend
             more
             time
             about
             it
             .
             Not
             to
             examine
             here
             whether
             what
             has
             been
             related
             ,
             so
             as
             to
             make
             it
             probable
             that
             ascending
             Water
             may
             carry
             up
             wherewithall
             to
             heighten
             and
             increase
             the
             Pipes
             or
             vessels
             through
             which
             it
             rises
             ,
             may
             contribute
             any
             thing
             more
             then
             was
             suggested
             in
             the
             former
             28
             th
             Experiment
             ,
             towards
             the
             Explication
             of
             the
             Rising
             and
             diffusing
             of
             the
             Sap
             in
             Trees
             .
          
        
         
           
           
             EXPERIMENT
             XXX
             .
          
           
             About
             an
             attempt
             to
             measure
             the
             Gravity
             of
             Cylinders
             of
             the
             Atmosphere
             ,
             so
             as
             that
             it
             may
             be
             exprest
             by
             known
             and
             common
             Weights
             .
          
           
             VVHilst
             I
             was
             making
             the
             former
             Experiments
             ,
             't
             was
             more
             than
             once
             my
             wish
             ,
             that
             by
             knowing
             the
             just
             weight
             of
             a
             Cylinder
             of
             Quick-silver
             of
             a
             determinate
             Diameter
             ,
             and
             of
             29
             or
             30
             inches
             high
             ,
             which
             is
             near
             the
             height
             that
             the
             Air
             does
             usually
             counterballance
             ,
             I
             might
             the
             better
             estimate
             the
             weight
             of
             a
             Cylinder
             of
             the
             Atmosphere
             of
             that
             Diameter
             ,
             and
             consequently
             make
             the
             better
             Guesses
             how
             near
             the
             effects
             of
             the
             Spring
             of
             the
             Air
             (
             as
             well
             as
             of
             its
             Weight
             ,
             )
             produc'd
             by
             the
             help
             of
             our
             Engine
             ,
             approach'd
             to
             the
             utmost
             of
             what
             might
             have
             been
             expected
             ,
             in
             case
             all
             the
             instruments
             imployed
             had
             been
             perfect
             ,
             and
             all
             concurrent
             circumstances
             had
             been
             favourable
             :
             And
             upon
             this
             account
             I
             several
             times
             regretted
             my
             want
             of
             a
             long
             Instrument
             of
             Steel
             or
             hardned
             Iron
             ,
             wherewith
             I
             many
             years
             since
             made
             an
             Observation
             ,
             that
             was
             more
             carefully
             registred
             than
             preserved
             ,
             of
             the
             weight
             of
             a
             Mercurial
             Cylinder
             of
             a
             determinate
             height
             as
             well
             as
             Diameter
             ;
             which
             weight
             I
             did
             not
             think
             it
             so
             safe
             to
             determine
             by
             the
             help
             of
             Glass-Tubes
             ,
             because
             t
             is
             very
             difficult
             to
             have
             them
             uniformly
             Cylindrical
             ,
             and
             to
             know
             that
             they
             are
             so
             ,
             in
             regard
             that
             they
             are
             form'd
             but
             by
             blowing
             and
             drawing
             out
             ,
             and
             ,
             besides
             the
             inequality
             that
             may
             happen
             to
             the
             Cavity
             upon
             other
             accounts
             ,
             t
             is
             very
             difficult
             to
             make
             the
             sides
             of
             the
             Glass
             equally
             thick
             ,
             and
             to
             examine
             whether
             they
             be
             so
             or
             no.
             
          
           
             But
             at
             length
             lighting
             upon
             (
             what
             I
             had
             too
             often
             wanted
             in
             the
             foregoing
             Experiments
             )
             a
             dexterous
             Artificer
             ,
             that
             chanced
             to
             come
             for
             a
             while
             to
             the
             place
             where
             I
             then
             was
             ,
             I
             indeavour'd
             to
             repair
             my
             loss
             ,
             as
             well
             as
             he
             could
             help
             me
             to
             do
             it
             ,
             by
             causing
             
             him
             to
             turn
             very
             carefully
             a
             Cylindrical
             piece
             of
             Brass
             ,
             of
             an
             inch
             in
             Diameter
             ,
             and
             3
             inches
             in
             length
             ,
             and
             open
             (
             that
             it
             might
             be
             the
             better
             wrought
             )
             at
             both
             ends
             ,
             to
             one
             of
             which
             was
             exactly
             fitted
             a
             flat
             bottom
             of
             the
             same
             Metal
             ,
             fastned
             very
             close
             to
             it
             with
             little
             Screws
             on
             the
             outside
             ;
             this
             being
             judg'd
             a
             better
             way
             ,
             than
             if
             it
             had
             been
             turn'd
             all
             of
             a
             piece
             :
          
           
             This
             instrument
             being
             diligently
             counterpois'd
             in
             a
             trusty
             pair
             of
             Scales
             ,
             was
             carefully
             fill'd
             with
             Mercury
             ,
             which
             (
             for
             greater
             caution
             )
             we
             took
             out
             of
             a
             new
             parcel
             ,
             that
             we
             had
             not
             yet
             imployed
             about
             other
             Experiments
             ,
             and
             finding
             it
             to
             weigh
             XVII
             Ounces
             ,
             one
             Dram
             ,
             45
             Gr
             :
             Troy
             weight
             ,
             (
             or
             137
             dr
             :
             45
             gr
             :
             )
             multiplying
             that
             by
             10
             ,
             there
             will
             come
             for
             the
             weight
             of
             a
             Mercurial
             Cylinder
             ,
             of
             one
             inch
             in
             Diameter
             ,
             and
             30
             inches
             in
             height
             ,
             (
             and
             so
             high
             I
             have
             divers
             times
             seen
             the
             Mercury
             to
             be
             in
             a
             good
             Barometer
             ,
             )
             about
             14
             ,
             
               2l
               ,
               (
               i.e.
               14l
            
             ,
             2
             Ounces
             ,
             and
             above
             three
             drams
             ,
             Troy-weight
             ;
             and
             almost
             11
             ,
             8l
             .
             Haberdupoise
             weight
             ,
             (
             
               i.e.
               11l
            
             ,
             12
             Ounces
             ,
             and
             above
             6
             Drams
             ,
             )
             which
             is
             a
             greater
             weight
             than
             without
             such
             a
             Tryal
             one
             would
             easily
             imagine
             that
             so
             short
             a
             Cylinder
             of
             Mercury
             ,
             and
             much
             less
             that
             a
             Cylinder
             of
             so
             light
             a
             Body
             as
             Air
             ,
             being
             neither
             of
             them
             above
             an
             Inch
             Diameter
             ,
             could
             amount
             to
             .
          
           
             Note
             First
             ,
             to
             examine
             at
             the
             same
             time
             the
             weight
             of
             the
             Mercury
             ,
             and
             its
             proportion
             to
             Water
             ,
             we
             did
             ,
             before
             the
             Mercury
             was
             pour'd
             into
             the
             Brass-vessel
             ,
             fill
             it
             with
             Water
             ,
             (
             after
             which
             we
             wip'd
             it
             dry
             before
             the
             Mercury
             was
             put
             into
             it
             ;
             )
             and
             this
             liquor
             weighing
             10
             drams
             ,
             and
             15
             gr
             :
             the
             proportion
             between
             the
             Mercury
             and
             the
             Water
             appeard
             to
             be
             that
             of
             13
             18
             /
             41
             to
             1
             :
             which
             though
             it
             seem
             somewhat
             of
             the
             least
             ,
             yet
             Your
             Lordship
             may
             remember
             ,
             that
             I
             formerly
             told
             You
             I
             had
             several
             times
             found
             the
             receiv'd
             proportion
             of
             14
             to
             1
             ,
             between
             Mercury
             and
             Water
             ,
             to
             be
             somewhat
             too
             great
             ;
             and
             besides
             that
             ,
             in
             a
             vessel
             whose
             orifice
             was
             no
             lesse
             than
             an
             inch
             in
             Diameter
             ,
             t
             is
             exceeding
             difficult
             to
             be
             sure
             when
             t
             is
             precisely
             full
             either
             of
             Water
             or
             Mercury
             ;
             because
             the
             former
             has
             a
             Superficies
             considerably
             concave
             ,
             
             and
             the
             other
             one
             that
             is
             notably
             convex
             ,
             and
             though
             we
             us'd
             some
             litle
             Artifices
             (
             which
             would
             be
             troublesome
             here
             to
             mention
             )
             to
             estimate
             the
             proturberance
             of
             the
             one
             liquor
             ,
             and
             the
             deficience
             of
             the
             other
             ,
             as
             near
             the
             truth
             as
             could
             be
             ,
             yet
             I
             am
             not
             sure
             but
             there
             may
             have
             been
             a
             few
             Mercurial
             Corpuscles
             more
             than
             there
             should
             have
             been
             ,
             and
             that
             consequently
             some
             small
             abatement
             may
             have
             been
             made
             of
             the
             weight
             newly
             attributed
             to
             the
             whole
             Mercurial
             Cylinder
             of
             30
             inches
             .
          
           
             2.
             
             I
             had
             thoughts
             of
             making
             use
             of
             the
             Barrel
             of
             a
             Gun
             ,
             of
             a
             convenient
             length
             ,
             to
             find
             the
             weight
             of
             a
             Mercurial
             Cylinder
             of
             2
             foot
             and
             1
             /
             2
             ,
             but
             I
             preferr'd
             the
             Instrument
             already
             made
             use
             of
             (
             especially
             not
             being
             where
             I
             could
             have
             one
             bored
             after
             a
             peculiar
             way
             ,
             )
             not
             onely
             because
             I
             could
             not
             meet
             with
             one
             whose
             Diameter
             was
             a
             just
             inch
             ,
             and
             consequently
             as
             convenient
             for
             calculations
             ,
             and
             because
             that
             the
             Barrels
             of
             Guns
             are
             often
             bor'd
             a
             litle
             Tapering
             ;
             but
             because
             a
             skilful
             Artificer
             confest
             to
             me
             ,
             that
             they
             scarce
             ever
             bore
             such
             Barrels
             ,
             but
             with
             a
             foure-square
             Bit
             ,
             (
             as
             they
             call
             it
             ,
             )
             which
             leaves
             the
             Cavity
             too
             Angular
             ,
             or
             too
             imperfectly
             round
             ;
             whereas
             if
             an
             Hexahedrical
             Bit
             be
             imploy'd
             it
             will
             ,
             as
             he
             affirm'd
             ,
             make
             the
             Cavity
             almost
             as
             Cylindrical
             as
             can
             be
             reasonably
             desired
             .
             I
             say
             nothing
             here
             of
             making
             use
             for
             our
             purpose
             of
             a
             Trunk
             ,
             as
             they
             call
             a
             hollow
             Cylinder
             of
             Wood
             ,
             because
             I
             elsewhere
             shew
             ,
             that
             Wood
             (
             at
             least
             such
             as
             the
             Trunks
             to
             shoot
             Pellets
             with
             are
             wont
             to
             be
             made
             of
             )
             is
             not
             of
             a
             Texture
             close
             enough
             for
             such
             an
             use
             .
          
           
             3.
             
             Because
             in
             Cylinders
             of
             Mercury
             ,
             30
             inches
             is
             a
             height
             which
             the
             Atmosphere
             is
             seldome
             heavy
             enough
             to
             be
             able
             to
             counterpoise
             ,
             and
             because
             29
             inches
             is
             somewhat
             nearer
             the
             middle
             between
             the
             greatest
             and
             the
             least
             heights
             ,
             at
             which
             I
             have
             observed
             the
             Mercury
             at
             differing
             times
             to
             stand
             in
             good
             Barometers
             .
             Your
             Lordship
             may
             ,
             if
             You
             please
             ,
             abate
             a
             30
             th
             part
             of
             the
             weight
             assign'd
             above
             to
             a
             Mercurial
             Cylinder
             of
             30
             inches
             ,
             (
             though
             I
             take
             29
             and
             ¼
             ,
             or
             thereabouts
             ,
             to
             be
             somewhat
             a
             more
             usual
             height
             of
             the
             Mercury
             ,
             than
             precisely
             Nine
             and
             twenty
             .
             )
          
           
           
             4.
             
             The
             Weight
             of
             a
             Mercurial
             Cylinder
             in
             an
             Aequilibrium
             with
             the
             Atmosphere
             ,
             and
             of
             one
             inch
             in
             Diameter
             being
             thus
             setled
             ,
             we
             may
             ,
             by
             the
             help
             of
             the
             doctrine
             of
             Proportions
             ,
             and
             a
             few
             Propositions
             ,
             especially
             the
             14
             th
             of
             the
             12
             th
             book
             of
             Euclides
             Elements
             ,
             easily
             enough
             calculate
             the
             weight
             of
             a
             Cylinder
             of
             Mercury
             of
             another
             Diameter
             ,
             and
             consequently
             the
             force
             of
             the
             Pressure
             of
             an
             Atmospherical
             Pillar
             of
             the
             same
             Diameter
             .
             For
             since
             according
             to
             the
             forenam'd
             14
             th
             Proposition
             of
             the
             12
             th
             ,
             Cylinders
             of
             equal
             Bases
             are
             to
             one
             another
             as
             their
             Heights
             ;
             and
             since
             by
             the
             2
             d
             Proposition
             of
             the
             same
             12.
             
             Element
             ,
             Circles
             such
             as
             are
             the
             Bases
             of
             Cylinders
             )
             are
             to
             one
             another
             ,
             as
             the
             Squares
             of
             their
             Diameters
             ;
             and
             since
             lastly
             we
             suppose
             ,
             that
             Mercury
             being
             a
             Homogeneous
             body
             ,
             at
             least
             as
             to
             sense
             ,
             the
             Mercurial
             Cylinders
             will
             have
             the
             same
             proportion
             to
             each
             other
             in
             Weight
             that
             they
             have
             in
             Bulk
             ;
             since
             ,
             I
             say
             ,
             these
             things
             are
             so
             ,
             if
             ,
             for
             instance
             ,
             we
             desire
             to
             know
             what
             will
             be
             the
             weight
             of
             a
             Cylinder
             of
             30
             inches
             high
             ,
             whose
             Diameter
             is
             two
             inches
             ,
             the
             Rule
             will
             be
             this
             .
          
           
             As
             the
             square
             of
             the
             Diameter
             of
             the
             Standard
             Cylinder
             ,
             (
             as
             I
             call
             that
             whose
             weight
             is
             already
             known
             )
             is
             to
             the
             square
             of
             the
             Diameter
             of
             the
             Cylinder
             propos'd
             ,
             so
             will
             the
             bulk
             of
             the
             former
             Cylinder
             be
             to
             that
             of
             the
             later
             ,
             and
             the
             weight
             of
             that
             to
             the
             weight
             of
             this
             .
          
           
             According
             to
             which
             Rule
             ,
             the
             square
             of
             1
             inch
             (
             which
             is
             the
             Diameter
             of
             the
             standard
             Cylinder
             )
             being
             but
             1
             ,
             (
             whereby
             Your
             Lordship
             may
             perceive
             how
             much
             the
             measure
             I
             pitcht
             on
             facilitates
             Computations
             ,
             )
             and
             the
             square
             of
             2
             (
             which
             is
             the
             Diameter
             of
             the
             propos'd
             Cylinder
             )
             being
             4
             ,
             the
             bulk
             or
             solid
             Contents
             of
             this
             later
             Cylinder
             ,
             and
             consequently
             its
             Weight
             ,
             will
             be
             4
             times
             as
             great
             as
             those
             of
             the
             standard
             Cylinder
             ;
             and
             so
             ,
             since
             the
             lesser
             has
             been
             already
             suppos'd
             to
             weigh
             11
             ,
             8l
             Haberdupoise
             ,
             the
             Mercurial
             Cylinder
             of
             two
             inches
             in
             Diameter
             ,
             will
             weigh
             47
             ,
             2l
             of
             the
             same
             weight
             .
          
        
         
           
           
             EXPERIMENT
             XXXI
             .
          
           
             About
             the
             Attractive
             virtue
             of
             the
             Loadstone
             in
             an
             Exhausted
             Receiver
             .
          
           
             SOme
             Learned
             modern
             Philosophers
             ,
             that
             have
             attempted
             to
             explicate
             the
             cause
             and
             manner
             of
             Magnetical
             Attraction
             or
             Coition
             ,
             give
             such
             an
             account
             of
             it
             ,
             as
             supposes
             ,
             that
             the
             Air
             between
             the
             two
             Magnetical
             Bodies
             ,
             being
             driven
             away
             by
             their
             Effluviums
             from
             between
             them
             ,
             presses
             them
             on
             the
             parts
             opposite
             to
             those
             where
             the
             Contact
             is
             to
             be
             made
             ;
             and
             upon
             some
             such
             score
             (
             for
             I
             must
             not
             now
             stay
             to
             deliver
             their
             Theories
             Circumstantially
             )
             the
             Air
             is
             suppos'd
             to
             contribute
             very
             much
             to
             the
             Attraction
             and
             Sustentation
             of
             the
             Iron
             by
             the
             Loadstone
             :
             wherefore
             partly
             to
             examine
             this
             Opinion
             ,
             and
             partly
             for
             some
             other
             Purposes
             (
             not
             necessary
             now
             to
             be
             mentioned
             )
             we
             thought
             fit
             to
             make
             the
             following
             Exptriment
             .
          
           
             We
             took
             a
             small
             but
             vigorous
             Loadstone
             ,
             cap'd
             and
             fitted
             with
             a
             loose
             plate
             of
             Steel
             ,
             so
             shap'd
             ,
             that
             when
             it
             was
             sustained
             by
             the
             Loadstone
             ,
             we
             could
             hang
             at
             a
             litle
             Crook
             ,
             that
             came
             out
             of
             the
             midst
             of
             it
             ,
             and
             pointed
             downwards
             ,
             a
             Scale
             ,
             wherein
             to
             put
             what
             Weights
             we
             should
             think
             fit
             .
             Into
             this
             Scale
             we
             put
             sometimes
             more
             and
             sometimes
             less
             weight
             ,
             and
             then
             by
             shaking
             of
             the
             Loadstone
             as
             much
             as
             we
             guess'd
             it
             would
             be
             shaken
             by
             the
             motion
             of
             the
             Engine
             ,
             we
             found
             the
             greatest
             weight
             ,
             that
             we
             presum'd
             it
             would
             be
             able
             to
             support
             ,
             in
             spite
             of
             the
             Agitation
             't
             would
             be
             exposed
             to
             ,
             which
             prov'd
             to
             be
             ,
             besides
             the
             Iron-plate
             and
             the
             Scale
             ,
             VI
             Ounces
             Troy
             weight
             ,
             to
             which
             if
             we
             added
             half
             an
             ounce
             more
             ,
             the
             whole
             weight
             appear'd
             too
             easie
             to
             be
             shaken
             off
             .
             This
             done
             ,
             we
             hung
             the
             Loadstone
             ,
             with
             all
             the
             weight
             it
             sustain'd
             ,
             at
             a
             Button
             of
             Glass
             ,
             which
             we
             had
             procur'd
             to
             be
             fastned
             on
             to
             the
             top
             of
             the
             inside
             of
             a
             Receiver
             ,
             when
             't
             was
             first
             blown
             ,
             and
             though
             in
             about
             12
             Exuctions
             we
             usually
             emptied
             such
             Receivers
             as
             
             as
             much
             as
             was
             requisite
             for
             most
             Experiments
             ;
             yet
             this
             time
             ,
             to
             exhaust
             it
             the
             more
             accurately
             ,
             we
             continued
             pumping
             till
             we
             had
             exceeded
             twice
             that
             number
             of
             Exuctions
             ,
             at
             the
             end
             of
             which
             time
             shaking
             the
             Engine
             somewhat
             rudely
             ,
             without
             thereby
             shaking
             off
             the
             Weight
             that
             hung
             at
             the
             Loastone
             ,
             the
             Iron
             seem'd
             to
             be
             very
             near
             as
             firmly
             sustain'd
             by
             it
             as
             before
             the
             Air
             began
             to
             be
             pump'd
             out
             .
             I
             said
             very
             near
             ,
             rather
             than
             altogether
             ,
             because
             that
             the
             withdrawing
             of
             the
             Air
             ,
             though
             it
             be
             not
             suppos'd
             to
             weaken
             at
             all
             the
             Power
             of
             the
             Loadstone
             precisely
             considered
             ,
             yet
             it
             must
             lessen
             its
             power
             to
             sustain
             the
             Steel
             ,
             because
             this
             in
             so
             thin
             a
             medium
             must
             weigh
             heavier
             ,
             than
             in
             the
             Air
             ,
             by
             the
             weight
             of
             as
             much
             Air
             ,
             as
             is
             equal
             in
             bulk
             to
             the
             appended
             Body
             .
          
           
             Some
             other
             Magnetical
             Tryals
             (
             and
             also
             some
             Electrical
             ones
             )
             I
             remember
             I
             attempted
             to
             make
             by
             the
             help
             of
             our
             Engine
             ,
             but
             not
             having
             the
             Notes
             I
             took
             of
             them
             now
             at
             hand
             ,
             I
             shall
             suspend
             the
             mentioning
             them
             ,
             till
             I
             can
             give
             Your
             Lordship
             a
             more
             punctual
             Account
             of
             them
             .
          
        
         
           
             EXPERIMENT
             XXXII
             .
          
           
             Shewing
             ,
             that
             when
             the
             Pressure
             of
             the
             External
             Air
             is
             taken
             off
             ,
             t
             is
             very
             easie
             to
             draw
             up
             the
             Sucker
             of
             a
             Syringe
             ,
             though
             the
             Hole
             ,
             at
             which
             the
             Air
             or
             Water
             should
             succeed
             ,
             be
             stopp'd
             .
          
           
             HAving
             taken
             notice
             ,
             that
             some
             learned
             Opposers
             of
             the
             Modern
             Doctrine
             about
             the
             weight
             of
             the
             Atmosphere
             think
             themselves
             more
             than
             ordinarily
             befriended
             by
             the
             difficulty
             we
             find
             in
             drawing
             up
             the
             Embolus
             or
             Sucker
             of
             a
             Syringe
             ,
             when
             the
             hole
             ,
             at
             which
             the
             Air
             or
             Water
             should
             succeed
             ,
             is
             stopt
             ,
             and
             by
             the
             violence
             ,
             with
             which
             ,
             as
             soon
             as
             t
             is
             let
             go
             ,
             tis
             ,
             as
             they
             imagine
             ,
             drawn
             back
             .
             And
             supposing
             the
             reason
             of
             this
             confidence
             of
             theirs
             to
             be
             ,
             that
             Men
             have
             not
             yet
             been
             able
             in
             these
             Phaenomena
             
             (
             as
             in
             some
             others
             )
             to
             prove
             the
             interest
             of
             the
             Atmosphere's
             Gravity
             by
             direct
             or
             confessedly
             analogous
             Experiments
             ;
             I
             presum'd
             it
             will
             not
             be
             unwelcome
             to
             Your
             Lordship
             ,
             if
             I
             here
             fortifie
             the
             Speculations
             that
             have
             been
             or
             may
             be
             propos'd
             to
             explicate
             these
             things
             according
             to
             the
             Hypothesis
             of
             the
             weight
             of
             the
             Air
             ,
             by
             what
             we
             tried
             to
             that
             purpose
             ,
             among
             others
             ,
             when
             we
             were
             making
             use
             of
             a
             Syringe
             in
             our
             Engine
             .
          
           
             
               The
               I.
               Tryal
               .
            
             
               We
               took
               a
               Syringe
               of
               Brass
               ,
               (
               that
               Metal
               being
               closer
               and
               stronger
               then
               Pewter
               ,
               of
               which
               such
               instruments
               are
               usually
               made
               ,
               )
               being
               in
               length
               (
               in
               the
               Barrel
               )
               about
               6
               inches
               ,
               and
               in
               Diameter
               about
               1
               inch
               ⅜
               and
               having
               ,
               by
               putting
               a
               thin
               Bladder
               about
               the
               Sucker
               ,
               and
               by
               pouring
               a
               litle
               Oyl
               into
               the
               cavity
               of
               the
               Cylinder
               (
               or
               Barrel
               ,
               )
               brought
               the
               instrument
               to
               be
               stanch
               enough
               ,
               and
               yet
               the
               Sucker
               to
               move
               to
               and
               fro
               without
               much
               difficulty
               ,
               we
               thrust
               this
               to
               the
               bottom
               (
               or
               Basis
               )
               of
               the
               Barrel
               to
               exclude
               the
               Air
               ,
               and
               having
               unscrew'd
               and
               laid
               aside
               the
               slender
               Pipe
               of
               the
               Syringe
               (
               which
               in
               this
               and
               some
               other
               Tryals
               was
               like
               to
               prove
               not
               onely
               needless
               ,
               but
               inconvenient
               )
               we
               carefully
               stopt
               the
               Orifice
               ,
               to
               which
               the
               Pipe
               in
               these
               instruments
               is
               wont
               to
               be
               screw'd
               ,
               and
               then
               drawing
               up
               the
               Sucker
               we
               let
               it
               go
               ,
               to
               judg
               by
               the
               violence
               ,
               with
               which
               it
               would
               be
               driven
               back
               again
               ,
               whether
               the
               Syringe
               were
               light
               enough
               for
               our
               purpose
               ,
               and
               finding
               it
               to
               be
               so
               ,
               we
               fastned
               to
               the
               Barrel
               a
               ponderous
               piece
               of
               Iron
               to
               keep
               it
               down
               ,
               and
               then
               fastning
               to
               the
               handle
               of
               the
               Rammer
               (
               or
               Axle-tree
               of
               the
               Sucker
               )
               one
               end
               of
               a
               String
               ,
               whose
               other
               end
               was
               tied
               to
               the
               often
               mentioned
               turning-key
               :
               We
               convey'd
               this
               Syringe
               ,
               and
               the
               weight
               belonging
               unto
               it
               ,
               into
               a
               Receiver
               ;
               and
               having
               pump'd
               out
               the
               Air
               ,
               we
               then
               began
               to
               turn
               the
               Key
               ,
               thereby
               to
               shorten
               the
               String
               that
               tied
               the
               handle
               of
               the
               Syringe
               to
               it
               ;
               and
               ,
               as
               we
               foretold
               ,
               that
               the
               Pressure
               of
               the
               Air
               ,
               lately
               included
               in
               the
               Receiver
               ,
               being
               withdrawn
               ,
               we
               should
               no
               more
               find
               the
               wonted
               
               resistance
               in
               drawing
               up
               the
               Sucker
               from
               the
               bottom
               of
               the
               Cylinder
               ,
               so
               we
               found
               upon
               Tryal
               that
               we
               could
               very
               easily
               pull
               it
               up
               without
               finding
               any
               sensible
               resistance
               .
            
             
               However
               having
               thought
               fit
               to
               repeat
               the
               Experiment
               ,
               (
               which
               we
               did
               with
               the
               like
               success
               ,
               )
               lest
               it
               might
               might
               be
               objected
               ,
               that
               this
               want
               of
               resistance
               might
               proceed
               ,
               as
               partly
               from
               our
               imploying
               the
               Turning-key
               to
               raise
               the
               Sucker
               ,
               so
               principally
               from
               some
               unperceived
               Leak
               ,
               at
               which
               the
               Air
               may
               be
               suppos'd
               to
               have
               got
               into
               the
               cavity
               of
               the
               Cylinder
               ;
               I
               thought
               fit
               
                 not
                 onely
              
               to
               examine
               by
               Tryal
               ,
               after
               the
               Receiver
               was
               remov'd
               from
               off
               the
               Pump
               ,
               whether
               the
               Syringe
               were
               not
               stanch
               ,
               (
               upon
               which
               I
               found
               that
               I
               could
               not
               ,
               without
               some
               straining
               ,
               draw
               up
               the
               Sucker
               even
               a
               litle
               way
               ,
               and
               that
               it
               would
               be
               violently
               beaten
               back
               again
               ,
               )
               
                 but
                 also
              
               in
               one
               of
               these
               Experiments
               to
               make
               this
               variation
               ;
               That
               when
               ,
               the
               Receiver
               being
               exhausted
               ,
               we
               had
               drawn
               up
               the
               Sucker
               almost
               to
               the
               top
               of
               the
               Barrel
               by
               such
               a
               string
               as
               was
               purposely
               chosen
               somewhat
               weak
               ,
               we
               kept
               the
               parts
               of
               the
               Syring
               in
               that
               posture
               ,
               till
               we
               had
               open'd
               a
               passage
               to
               the
               outward
               Air
               ,
               upon
               whose
               ingress
               the
               Sucker
               was
               (
               as
               we
               intended
               it
               should
               be
               )
               so
               forceably
               deprest
               ,
               that
               it
               broke
               the
               String
               by
               which
               it
               was
               tied
               to
               the
               Turning-key
               ,
               and
               was
               violently
               driven
               back
               to
               the
               lower
               part
               of
               the
               Barrel
               ,
               &
               that
               notwithstanding
               these
               two
               disadvantageous
               Circumstances
               ;
               one
               ,
               that
               the
               string
               was
               not
               so
               weak
               ,
               but
               that
               one
               ,
               whom
               I
               imploy'd
               to
               try
               it
               before
               it
               was
               fastned
               to
               the
               Syringe
               ,
               made
               it
               sustain
               a
               lump
               of
               Iron
               that
               weighed
               between
               four
               and
               five
               pound
               ;
               and
               the
               other
               ,
               that
               yet
               this
               string
               was
               broken
               long
               before
               all
               the
               Air
               ,
               that
               flowed
               in
               to
               fill
               the
               Receiver
               ,
               had
               got
               in
               :
               so
               that
               the
               pressure
               of
               all
               the
               admitted
               Air
               would
               doubtless
               have
               broken
               a
               much
               stronger
               string
               ,
               if
               we
               had
               imploy'd
               such
               a
               one
               to
               resist
               the
               depression
               of
               the
               Sucker
               ,
               which
               will
               yet
               be
               more
               evident
               by
               a
               phaenomenon
               of
               our
               Syringe
               ,
               that
               I
               shall
               presently
               have
               occasion
               to
               relate
               .
            
          
           
             
             
               The
               II.
               TRYAL
               .
            
             
               Containing
               a
               Variation
               of
               the
               foregoing
               .
            
             
               We
               took
               the
               Syringe
               imploy'd
               in
               the
               foregoing
               Experiments
               ,
               and
               having
               found
               by
               Tryal
               that
               it
               was
               ,
               though
               not
               perfectly
               ,
               tite
               ,
               (
               nor
               altogether
               so
               much
               so
               as
               before
               ,
               )
               yet
               enough
               so
               for
               our
               present
               purpose
               ,
               (
               since
               ,
               when
               the
               Orifice
               of
               the
               vent
               in
               the
               Basis
               was
               stopt
               ,
               if
               the
               Sucker
               were
               more
               forceably
               drawn
               up
               a
               litle
               way
               ,
               and
               then
               let
               go
               ,
               it
               would
               hastily
               return
               ,
               or
               rather
               violently
               be
               impell'd
               back
               towards
               the
               bottom
               of
               the
               Barrel
               ,
               )
               we
               made
               it
               serve
               us
               as
               well
               as
               we
               could
               for
               the
               following
               Experiment
               .
               Of
               this
               Syringe
               we
               did
               very
               carefully
               with
               a
               Cork
               and
               our
               Cement
               close
               the
               vent
               ;
               and
               then
               having
               tied
               to
               the
               barrel
               of
               the
               Syring
               a
               Weight
               that
               hapned
               to
               be
               at
               hand
               ,
               (
               and
               to
               amount
               to
               2
               Pound
               ,
               and
               as
               many
               Ounces
               ,
               )
               we
               suspended
               the
               Rammer
               of
               the
               Syringe
               by
               a
               string
               in
               a
               large
               Receiver
               ;
               and
               then
               causing
               the
               Pump
               to
               be
               applied
               ,
               we
               made
               11
               or
               12
               Exuctions
               of
               the
               Air
               ,
               without
               any
               appearance
               of
               change
               in
               the
               Syringe
               :
               but
               because
               I
               had
               judg'd
               the
               above
               mentioned
               Weight
               sufficient
               ,
               and
               suppos'd
               that
               the
               little
               Air
               still
               remaining
               in
               the
               Receiver
               ,
               had
               yet
               too
               strong
               a
               Pressure
               to
               be
               surmounted
               by
               it
               ,
               I
               caus'd
               the
               Pumping
               to
               be
               continued
               ,
               and
               within
               2
               or
               three
               Exuctions
               more
               I
               perceiv'd
               the
               Cylinder
               to
               begin
               to
               be
               drawn
               down
               (
               though
               but
               very
               slowly
               )
               by
               the
               Weight
               hanging
               at
               it
               ,
               (
               assisted
               by
               its
               own
               Gravity
               :
               )
               and
               likewise
               tried
               (
               after
               having
               purposely
               stopt
               a
               while
               the
               working
               of
               the
               Pump
               )
               that
               just
               upon
               a
               fresh
               Suck
               the
               descent
               would
               be
               manifestly
               accelerated
               .
               And
               when
               we
               had
               suffer'd
               the
               Barrel
               and
               Weight
               to
               slide
               down
               as
               far
               as
               we
               thought
               fit
               ,
               we
               let
               in
               the
               External
               Air
               ,
               which
               (
               as
               was
               to
               be
               expected
               )
               rais'd
               them
               both
               again
               much
               faster
               than
               they
               had
               subsided
               .
            
             
               NB.
               There
               would
               not
               have
               needed
               any
               thing
               near
               so
               great
               a
               Weight
               to
               depress
               the
               Barrel
               of
               the
               Syringe
               ,
               but
               that
               it
               is
               difficult
               
               in
               such
               an
               instrument
               to
               make
               the
               Sucker
               fill
               it
               accurately
               enough
               ,
               without
               making
               it
               somewhat
               uneasie
               to
               be
               mov'd
               to
               and
               fro
               :
               Upon
               which
               account
               t
               was
               necessary
               that
               a
               Weight
               should
               be
               added
               ,
               not
               onely
               to
               surmount
               the
               Pressure
               of
               the
               Air
               remaining
               in
               the
               Receiver
               ,
               (
               which
               was
               not
               ,
               nor
               needed
               to
               be
               diligently
               exhausted
               in
               this
               Experiment
               ,
               )
               but
               to
               overcome
               that
               resistance
               ,
               which
               we
               just
               now
               noted
               the
               inequalities
               of
               the
               inside
               of
               the
               Cylinder
               and
               those
               of
               the
               Sucker
               to
               give
               to
               the
               motion
               of
               the
               one
               in
               or
               over
               the
               other
               .
               And
               yet
               for
               all
               this
               t
               is
               not
               easie
               ,
               though
               it
               be
               not
               impossible
               ,
               to
               make
               one
               of
               these
               Syringes
               very
               Tight
               ,
               especially
               when
               the
               Nose
               is
               well
               stopt
               ,
               and
               the
               Sucker
               drawn
               up
               ;
               there
               being
               often
               some
               litle
               Air
               that
               strains
               in
               between
               the
               Sucker
               and
               the
               Barrel
               ,
               and
               some
               that
               will
               be
               harbour'd
               between
               the
               Sucker
               (
               though
               thrust
               home
               )
               and
               the
               bottom
               of
               the
               Barrel
               ,
               besides
               what
               may
               lurk
               between
               the
               same
               Sucker
               and
               the
               Cork
               that
               stops
               the
               orifice
               of
               the
               Vent
               .
               Nor
               were
               we
               confident
               ,
               that
               our
               Syringe
               did
               not
               at
               length
               let
               some
               Aerial
               particles
               insinuate
               themselves
               into
               the
               Cavity
               ,
               which
               the
               depression
               of
               the
               Barrel
               had
               made
               betwixt
               the
               Bases
               of
               that
               Barrel
               and
               the
               Sucker
               :
               and
               in
               such
               cases
               we
               ought
               not
               to
               wonder
               ,
               if
               upon
               the
               return
               of
               the
               Air
               the
               Barrel
               and
               Weight
               be
               not
               impell'd
               up
               all
               together
               to
               the
               same
               height
               they
               rested
               at
               ,
               when
               they
               were
               first
               suspended
               in
               the
               Receiver
               .
            
             
               2.
               
               It
               agreed
               very
               well
               with
               our
               Doctrine
               ,
               that
               as
               the
               Cylinder
               and
               Weight
               began
               not
               to
               fall
               ,
               till
               a
               great
               quantity
               of
               Air
               had
               been
               pump'd
               out
               of
               the
               Receiver
               ,
               so
               they
               did
               not
               begin
               to
               move
               upwards
               presently
               upon
               the
               freedom
               that
               was
               allow'd
               the
               Air
               to
               return
               into
               the
               Receiver
               .
               For
               till
               it
               had
               continued
               a
               pretty
               while
               flowing
               in
               ,
               there
               was
               not
               enough
               of
               it
               entred
               to
               restore
               by
               its
               pressure
               the
               Cylinder
               and
               the
               annexed
               Weight
               to
               their
               former
               situation
               .
            
             
               3.
               
               What
               has
               been
               deliver'd
               about
               our
               Experiment
               may
               be
               confirm'd
               by
               this
               Variation
               which
               we
               made
               of
               it
               :
               That
               having
               substituted
               a
               far
               heavier
               Weight
               instead
               of
               that
               lately
               mention'd
               ,
               
               the
               depression
               of
               the
               Barrel
               of
               the
               Syringe
               succeeded
               2
               or
               3
               times
               one
               after
               another
               much
               sooner
               than
               formerly
               ,
               viz.
               about
               the
               sixth
               ,
               or
               at
               most
               ,
               the
               seaventh
               Exuction
               .
            
          
        
         
           
             EXPERIMENT
             XXXIII
             .
          
           
             About
             the
             opening
             of
             a
             Syringe
             ,
             whose
             Pipe
             was
             stopt
             in
             the
             Exhausted
             Receiver
             ,
             and
             by
             the
             help
             of
             it
             making
             the
             Pressure
             of
             the
             Air
             lift
             up
             a
             considerable
             Weight
             .
          
           
             THough
             the
             Trial
             I
             am
             about
             to
             relate
             ,
             had
             not
             all
             the
             success
             I
             desir'd
             ,
             yet
             perhaps
             it
             will
             not
             be
             impertinent
             to
             make
             mention
             of
             it
             ,
             because
             there
             is
             not
             any
             sort
             of
             Experiments
             ,
             that
             is
             wont
             so
             much
             to
             perswade
             the
             Generality
             of
             Spectators
             ,
             of
             the
             great
             force
             of
             the
             Pressure
             of
             the
             Air
             ,
             as
             those
             ,
             wherein
             they
             plainly
             see
             heavy
             and
             solid
             Bodies
             made
             to
             ascend
             ,
             (
             upon
             the
             operation
             of
             the
             Air
             on
             them
             ,
             )
             without
             seeing
             any
             other
             thing
             lift
             them
             up
             .
          
           
             We
             took
             the
             often
             mention'd
             Syringe
             ,
             and
             having
             clos'd
             up
             the
             Hole
             at
             the
             bottom
             with
             good
             Cement
             ,
             we
             ty'd
             to
             the
             Barrel
             a
             hollow
             piece
             of
             Iron
             ,
             that
             serv'd
             us
             for
             a
             Scale
             ,
             into
             which
             we
             put
             divers
             Weights
             one
             after
             another
             ,
             trying
             from
             time
             to
             time
             whether
             ,
             when
             the
             Sucker
             was
             forceably
             drawn
             up
             ,
             and
             held
             steddily
             in
             its
             highest
             station
             ,
             the
             Weight
             tyed
             to
             the
             Barrel
             (
             which
             was
             held
             down
             ,
             whilst
             the
             Sucker
             was
             drawn
             up
             ,
             and
             afterwards
             let
             go
             )
             would
             be
             considerably
             rais'd
             .
             And
             when
             we
             perceiv'd
             ,
             that
             the
             addition
             of
             half
             a
             Pound
             ,
             or
             a
             Pound
             more
             ,
             would
             make
             the
             Weight
             too
             Great
             to
             be
             so
             rais'd
             ,
             we
             forbore
             to
             put
             in
             that
             increase
             of
             weight
             ;
             and
             having
             tied
             the
             Handle
             of
             the
             Rammer
             to
             the
             Turning-key
             ,
             we
             convey'd
             the
             Syringe
             together
             with
             its
             clog
             into
             a
             Receiver
             ,
             out
             of
             which
             a
             convenient
             quantity
             of
             Air
             being
             pump'd
             ,
             we
             were
             thereby
             enabled
             easily
             to
             draw
             up
             the
             Sucker
             without
             the
             Cylinder
             ;
             after
             which
             having
             let
             in
             the
             Air
             ,
             the
             by-standers
             
             concluded
             ,
             that
             the
             weight
             was
             rais'd
             a
             litle
             ,
             which
             yet
             I
             would
             not
             have
             allow'd
             ,
             if
             we
             had
             not
             been
             able
             ,
             by
             inclining
             the
             Engine
             and
             the
             Receiver
             ,
             to
             make
             the
             Syringe
             and
             Weight
             a
             litle
             to
             swing
             .
             But
             to
             make
             the
             effect
             more
             evident
             ,
             I
             caus'd
             a
             two
             pound
             weight
             to
             be
             taken
             out
             ,
             and
             then
             the
             Receiver
             being
             somewhat
             exhausted
             ,
             and
             the
             Air
             readmitted
             ,
             the
             Clog
             ,
             when
             all
             the
             Air
             was
             come
             in
             ,
             was
             swiftly
             raised
             ,
             and
             as
             it
             were
             snatch'd
             up
             from
             the
             midle
             to
             the
             upper
             part
             of
             the
             suspended
             Rammer
             .
          
           
             It
             is
             no
             easie
             matter
             to
             measure
             ,
             with
             any
             certainty
             and
             exactness
             by
             a
             Syringe
             ,
             the
             weight
             of
             an
             Atmospherical
             Pillar
             equal
             to
             it
             in
             Diameter
             ,
             especially
             if
             there
             be
             any
             imperfection
             in
             the
             Syringe
             ,
             either
             because
             the
             Sucker
             does
             not
             go
             close
             enough
             ,
             in
             which
             case
             it
             can
             scarce
             be
             stanch
             ,
             or
             because
             by
             its
             Pressure
             against
             the
             inside
             of
             the
             Barrel
             (
             which
             often
             happens
             if
             it
             be
             too
             close
             )
             it
             hinders
             the
             Sucker
             and
             Barrel
             from
             sliding
             without
             resistance
             by
             one
             another
             ,
             and
             consequently
             there
             is
             an
             undue
             resistance
             made
             to
             the
             endeavour
             of
             the
             Atmosphere
             ,
             to
             raise
             the
             Barrel
             and
             Weight
             .
             And
             therefore
             ,
             though
             our
             Syringe
             being
             ,
             upon
             the
             account
             of
             some
             ill
             accident
             ,
             less
             in
             order
             than
             it
             was
             in
             some
             of
             the
             foregoing
             Experiments
             ,
             I
             must
             not
             conclude
             that
             a
             Cylinder
             of
             the
             Atmosphere
             of
             the
             same
             wideness
             with
             it
             ,
             is
             equipollent
             to
             no
             greater
             a
             weight
             ,
             than
             that
             which
             was
             taken
             up
             in
             our
             Trial
             ,
             yet
             we
             may
             safely
             conclude
             that
             so
             slender
             a
             Pillar
             of
             the
             Atmosphere
             is
             able
             to
             raise
             by
             a
             Syringe
             at
             least
             such
             a
             Weight
             ,
             as
             in
             our
             Experiment
             it
             actually
             lifted
             up
             ,
             which
             amounted
             to
             about
             sixteen
             pound
             (
             Haberdupoise
             weight
             ,
             )
             for
             it
             exceeded
             fifteen
             pound
             and
             three
             quarters
             ,
             besides
             the
             weight
             of
             the
             Syringes
             barrel
             it self
             .
          
        
         
           
           
             EXPERIMENT
             XXXIV
             .
          
           
             Shewing
             ,
             that
             the
             cause
             of
             the
             Ascension
             of
             Liquors
             in
             Syringes
             is
             to
             be
             deriv'd
             from
             the
             Pressure
             of
             the
             Air.
             
          
           
             I
             Shall
             not
             here
             trouble
             Your
             Lordship
             with
             what
             I
             have
             elsewhere
             propos'd
             about
             the
             explicating
             of
             Suction
             :
             but
             as
             by
             the
             lately
             recited
             Experiments
             (
             I
             mean
             the
             31
             ,
             32
             ,
             and
             33
             )
             it
             has
             appear'd
             ,
             that
             t
             is
             to
             the
             Pressure
             of
             the
             External
             Air
             that
             we
             should
             ascribe
             the
             difficulty
             of
             drawing
             up
             the
             Sucker
             of
             a
             Syring
             ,
             
               when
               the
               Pipe
            
             (
             or
             the
             Vent
             )
             
               is
               stopt
            
             ;
             so
             I
             shall
             now
             endeavour
             to
             shew
             ,
             that
             the
             Ascension
             of
             Liquors
             ,
             which
             follow
             the
             Sucker
             when
             t
             is
             drawn
             up
             ,
             the
             
               Pipe
               being
               open
            
             ,
             depends
             also
             upon
             the
             Pressure
             of
             the
             Air
             ,
             (
             incumbent
             on
             that
             Liquor
             .
             )
          
           
             If
             I
             had
             been
             furnish'd
             with
             very
             tall
             Receivers
             ,
             and
             such
             other
             Glasses
             as
             I
             could
             have
             wish'd
             ,
             I
             had
             tried
             the
             following
             Experiments
             with
             Water
             ,
             as
             well
             as
             Quick-silver
             ,
             but
             for
             want
             of
             those
             Accommodations
             I
             was
             reduc'd
             to
             make
             my
             Experiment
             with
             the
             later
             onely
             of
             those
             Liquors
             ,
             which
             yet
             will
             I
             hope
             sufficiently
             make
             out
             what
             was
             intended
             .
          
           
             
               The
               I.
               Tryal
               .
            
             
               We
               took
               a
               small
               Receiver
               ,
               shap'd
               almost
               like
               a
               Pear
               ,
               cut
               off
               Horizontally
               at
               both
               ends
               ,
               (
               being
               the
               same
               cap'd
               Glass
               that
               is
               elsewhere
               mentioned
               in
               the
               accounts
               of
               other
               Experiments
               :
               )
               
               we
               also
               took
               the
               Syringe
               formerly
               describ'd
               ,
               and
               having
               fastned
               on
               to
               it
               with
               good
               Cement
               ,
               in
               stead
               of
               its
               own
               Brass-pipe
               ,
               a
               small
               Glass
               pipe
               of
               about
               half
               a
               foot
               in
               length
               ,
               we
               put
               this
               Syringe
               in
               at
               the
               narrow
               end
               of
               the
               Receiver
               ;
               to
               whose
               Orifice
               was
               (
               afterwards
               )
               carefully
               cemented
               on
               the
               Brass-cap
               with
               the
               Turning-key
               ,
               whereto
               was
               tied
               by
               a
               string
               the
               handle
               of
               the
               Rammer
               .
               Then
               having
               conveniently
               plac'd
               upon
               the
               Engine
               a
               very
               short
               thick
               Glass
               shap'd
               like
               a
               Sugar-loaf
               ,
               (
               which
               was
               made
               use
               of
               for
               want
               of
               a
               better
               ,
               )
               with
               a
               sufficient
               Quantity
               of
               Quick-silver
               in
               it
               ;
               we
               
               so
               placed
               the
               Receiver
               over
               it
               ,
               that
               the
               lower
               end
               of
               the
               Pipe
               of
               the
               Syringe
               reacht
               almost
               to
               the
               bottom
               of
               this
               Glass
               ,
               and
               consequently
               was
               immerst
               a
               pretty
               way
               beneath
               the
               surface
               of
               the
               Quick
               silver
               .
               We
               had
               also
               poured
               a
               little
               Water
               in
               the
               upper
               part
               of
               the
               Syringe
               ,
               that
               no
               Air
               might
               get
               in
               between
               the
               Sucker
               and
               the
               Cylinder
               ,
               notwithstanding
               that
               by
               some
               Accident
               or
               other
               the
               Syringe
               was
               become
               somewhat
               less
               Tite
               than
               before
               .
               And
               last
               of
               all
               we
               cemented
               the
               Receiver
               to
               the
               Engine
               after
               the
               usual
               manner
               .
            
             
               That
               which
               now
               remained
               ,
               being
               to
               try
               the
               Experiment
               it self
               ,
               in
               order
               to
               which
               all
               this
               had
               been
               done
               ,
               the
               Air
               was
               pump'd
               out
               of
               the
               Receiver
               ,
               (
               and
               consequently
               out
               of
               the
               little
               Glass
               that
               held
               the
               Mercury
               ,
               )
               and
               then
               the
               Sucker
               being
               warily
               drawn
               up
               ,
               we
               could
               not
               see
               the
               Quick-silver
               ascend
               to
               follow
               it
               ,
               though
               a
               litle
               Water
               ,
               which
               it
               seems
               the
               outward
               Air
               had
               thrust
               in
               between
               the
               Sucker
               and
               the
               Cylinder
               ,
               was
               either
               rais'd
               or
               stopt
               in
               the
               Glass-pipe
               of
               the
               Syringe
               ,
               (
               whereof
               yet
               much
               the
               greatest
               part
               remain'd
               unfill'd
               ;
               )
               of
               which
               the
               reason
               according
               to
               our
               Hypothesis
               was
               manifest
               ,
               namely
               ,
               that
               the
               Air
               being
               pump'd
               out
               of
               the
               Receiver
               ,
               the
               litle
               that
               remain'd
               had
               not
               strength
               enough
               to
               press
               up
               so
               ponderous
               a
               Liquor
               as
               the
               Quick-silver
               into
               the
               Pipe
               ,
               (
               though
               even
               that
               litle
               unexhausted
               Air
               might
               have
               Spring
               enough
               left
               to
               raise
               a
               litle
               water
               .
               )
               And
               since
               it
               appear'd
               by
               this
               ,
               that
               without
               the
               Pressure
               of
               the
               Air
               the
               Quick-silver
               would
               not
               be
               elevated
               ,
               we
               thought
               it
               seasonable
               to
               shew
               ,
               that
               by
               the
               Pressure
               of
               the
               Air
               it
               would
               .
               Whereupon
               the
               Air
               being
               let
               slowly
               into
               the
               Receiver
               ,
               the
               Mercury
               was
               quickly
               impell'd
               up
               at
               least
               to
               the
               top
               of
               the
               Glass-pipe
               ,
               (
               though
               by
               reason
               of
               some
               unperceiv'd
               leak
               it
               was
               not
               long
               sustain'd
               there
               .
               )
            
             
               And
               for
               further
               satisfaction
               ,
               when
               the
               Experiment
               was
               to
               be
               tried
               over
               again
               ,
               we
               order'd
               it
               to
               be
               so
               made
               ,
               that
               it
               might
               plainly
               be
               observed
               ,
               that
               though
               when
               ,
               the
               Receiver
               not
               being
               yet
               exhausted
               ,
               the
               Sucker
               was
               drawn
               up
               but
               one
               inch
               ,
               the
               Mercury
               would
               be
               rais'd
               to
               the
               upper
               part
               of
               the
               Glass-pipe
               of
               the
               Syringe
               ,
               
               yet
               after
               the
               exhausting
               of
               the
               Receiver
               ,
               though
               the
               Sucker
               was
               drawn
               up
               twice
               as
               high
               ,
               there
               appear'd
               no
               ascension
               of
               the
               Mercury
               in
               the
               Pipe
               ,
               (
               whose
               lower
               part
               onely
               was
               darkned
               by
               the
               litle
               Glass
               which
               contain'd
               that
               fluid
               Metal
               .
               )
            
             
               Before
               I
               dismiss
               this
               Experiment
               ,
               I
               must
               ,
               to
               make
               good
               a
               promise
               I
               made
               Your
               Lordship
               ,
               acquaint
               You
               with
               a
               Phaenomenon
               ,
               which
               does
               not
               a
               litle
               confirm
               our
               Doctrine
               ,
               according
               to
               which
               it
               was
               easie
               both
               to
               foresee
               and
               to
               explain
               it
               :
               The
               phaenomenon
               was
               ,
               That
               if
               when
               the
               Air
               was
               diligently
               pump'd
               out
               of
               the
               Receiver
               ,
               the
               Sucker
               were
               endeavour'd
               to
               be
               pull'd
               up
               ,
               it
               could
               not
               be
               so
               ,
               without
               much
               difficulty
               and
               resistance
               ,
               such
               as
               was
               formerly
               found
               when
               the
               Vent
               of
               the
               Syringe
               was
               stopt
               ,
               of
               which
               in
               our
               Hypothesis
               the
               reason
               may
               be
               clearly
               this
               ;
               That
               there
               being
               no
               common
               Air
               in
               the
               Receiver
               to
               assist
               by
               its
               Pressure
               (
               whether
               immediate
               or
               mediate
               )
               the
               raising
               of
               the
               Sucker
               ,
               this
               could
               not
               be
               raised
               but
               by
               a
               force
               great
               enough
               to
               surmount
               the
               Weight
               of
               the
               external
               Air
               or
               Atmospherical
               Pillar
               that
               lean'd
               upon
               it
               .
               So
               that
               as
               the
               other
               Phaenomena
               of
               our
               Experiments
               manifest
               ,
               that
               the
               raising
               of
               Liquors
               by
               a
               Syringe
               ,
               which
               is
               commonly
               ascrib'd
               to
               Attraction
               ,
               depends
               upon
               the
               Pressure
               of
               the
               Air
               ;
               so
               by
               this
               Phaenomenon
               it
               appears
               ,
               that
               the
               difficulty
               of
               opening
               a
               Syringe
               ,
               whose
               Pipe
               is
               stopt
               ,
               need
               not
               be
               attributed
               to
               such
               a
               
                 fuga
                 vacui
              
               as
               vulgar
               Philosophers
               refer
               it
               to
               ;
               since
               in
               our
               case
               the
               same
               difficulty
               was
               found
               ,
               though
               the
               Pipe
               were
               open
               ,
               and
               the
               Liquor
               't
               was
               immerst
               in
               ,
               might
               have
               had
               free
               access
               to
               the
               place
               deserted
               by
               the
               Sucker
               .
            
          
           
             
               The
               II.
               Tryal
            
             
               Being
               a
               Prosecution
               of
               the
               former
               Attempt
               .
            
             
               To
               vary
               as
               well
               as
               confirm
               the
               foregoing
               Experiment
               ,
               we
               caus'd
               the
               Syringe
               to
               be
               tied
               fast
               to
               a
               competently
               ponderous
               Body
               that
               might
               keep
               the
               Cylinder
               unmov'd
               ,
               when
               the
               Sucker
               should
               be
               drawn
               up
               .
               We
               also
               cemented
               on
               to
               the
               vent
               or
               screw
               
               at
               the
               bottom
               of
               the
               Syringe
               a
               Pipe
               of
               glass
               of
               about
               two
               inches
               in
               length
               ,
               (
               which
               should
               have
               been
               longer
               ,
               but
               that
               then
               there
               would
               not
               have
               been
               room
               in
               the
               Receiver
               for
               the
               pulling
               up
               of
               the
               Sucker
               ,
               )
               and
               having
               plac'd
               the
               heavy
               Body
               whereto
               the
               Syringe
               was
               tied
               upon
               a
               Pedestal
               of
               a
               convenient
               height
               ,
               that
               the
               Glass-pipe
               might
               be
               all
               seen
               beneath
               it
               ,
               and
               a
               very
               low
               Viol
               almost
               fill'd
               with
               Quick-silver
               might
               be
               so
               plac'd
               underneath
               the
               Pipe
               ,
               that
               the
               stagnant
               Mercury
               reach'd
               a
               good
               way
               above
               the
               immerst
               orifice
               of
               the
               said
               Pipe.
               These
               things
               being
               thus
               provided
               ,
               and
               the
               Handle
               of
               the
               Syringes
               Rammer
               being
               tied
               with
               a
               string
               to
               the
               Turning-key
               that
               belong'd
               to
               the
               Brass-cover
               of
               the
               Receiver
               ,
               this
               vessel
               was
               cemented
               on
               to
               the
               Engine
               ,
               and
               by
               it
               Exhausted
               after
               the
               usual
               manner
               .
            
             
               When
               this
               was
               done
               ,
               we
               look'd
               upon
               the
               Syringes
               Glass-pipe
               above
               mentioned
               ,
               and
               being
               able
               to
               see
               through
               it
               ,
               (
               whereby
               we
               were
               certain
               that
               it
               was
               not
               yet
               full
               of
               Quick-silver
               )
               we
               did
               by
               the
               string
               draw
               up
               the
               Sucker
               to
               a
               good
               height
               ,
               but
               could
               not
               perceive
               the
               Pipe
               to
               be
               fill'd
               with
               any
               succeeding
               Mercury
               .
               Wherefore
               warily
               letting
               in
               some
               Air
               ,
               we
               quickly
               saw
               the
               Mercury
               impell'd
               to
               the
               very
               top
               of
               the
               Pipe
               ;
               and
               we
               concluded
               from
               the
               quantity
               of
               Quick-silver
               that
               was
               rais'd
               ,
               that
               a
               pretty
               deal
               was
               also
               driven
               into
               the
               cavity
               of
               the
               Cylinder
               .
            
             
               NB.
               I
               had
               once
               before
               seen
               the
               Mercury
               ascend
               into
               the
               Pipe
               upon
               the
               letting
               in
               of
               the
               Air
               into
               the
               emptied
               Receiver
               ,
               but
               it
               seeming
               somewhat
               difficult
               to
               me
               to
               determine
               whether
               the
               Sucker
               had
               been
               raised
               ,
               because
               there
               was
               no
               mark
               to
               guide
               my
               Aestimate
               by
               ,
               I
               thought
               it
               might
               be
               suspected
               ,
               that
               in
               case
               the
               Sucker
               had
               not
               been
               rais'd
               ,
               the
               Ascension
               of
               the
               Quick-silver
               might
               have
               proceeded
               from
               hence
               ,
               That
               the
               Air
               contain'd
               in
               the
               Glass-pipe
               ,
               breaking
               out
               through
               the
               stagnant
               Mercury
               upon
               the
               Exhausting
               of
               the
               Receiver
               ,
               the
               Quick-silver
               might
               upon
               the
               return
               of
               the
               Air
               into
               the
               Receiver
               be
               prest
               up
               into
               the
               place
               deserted
               by
               the
               Air
               ,
               that
               broke
               out
               of
               the
               Pipe.
               Wherefore
               we
               caus'd
               a
               string
               to
               be
               tied
               about
               the
               Rammer
               ,
               as
               near
               as
               we
               could
               to
               
               the
               top
               of
               the
               Cylinder
               ,
               by
               which
               means
               ,
               when
               the
               Receiver
               was
               the
               next
               time
               exhausted
               ,
               we
               perceiv'd
               ,
               that
               by
               drawing
               up
               the
               Sucker
               vve
               had
               rais'd
               it
               about
               two
               inches
               ,
               if
               not
               more
               ,
               and
               yet
               vve
               could
               not
               discern
               any
               Mercury
               to
               follow
               it
               ,
               (
               the
               Glass-pipe
               still
               continuing
               transparent
               ,
               )
               till
               we
               had
               let
               some
               Air
               return
               into
               the
               Receiver
               .
            
             
               This
               Experiment
               joyn'd
               with
               those
               we
               have
               formerly
               related
               to
               have
               been
               tried
               with
               our
               Syringe
               ,
               may
               teach
               us
               ,
               that
               if
               a
               Syringe
               were
               made
               use
               of
               above
               the
               Atmosphere
               ,
               neither
               the
               stopping
               of
               the
               Pipe
               vvould
               hinder
               the
               easy
               drawing
               up
               of
               the
               Sucker
               ,
               nor
               the
               drawing
               up
               of
               the
               Sucker
               ,
               though
               the
               Pipe
               vvere
               not
               stopt
               ,
               vvould
               raise
               by
               suction
               the
               Liquor
               vvhich
               the
               Pipe
               was
               immerst
               in
               .
            
          
           
             
               Postscript
               .
            
             
               SInce
               the
               last
               recited
               Experiment
               was
               made
               ,
               and
               written
               ,
               finding
               some
               of
               our
               Instruments
               to
               be
               in
               better
               order
               than
               they
               were
               when
               that
               Tryal
               was
               made
               ,
               vve
               thought
               fit
               to
               endeavour
               by
               that
               which
               follows
               ,
               to
               repair
               an
               omission
               or
               two
               ,
               that
               formerly
               we
               could
               not
               well
               avoid
               .
            
             
               Having
               then
               caus'd
               such
               a
               Glass-pipe
               ,
               as
               has
               been
               lately
               mentioned
               ,
               to
               be
               vvell
               cemented
               on
               to
               the
               Syringe
               ,
               (
               vvhose
               Sucker
               did
               now
               move
               more
               easily
               ,
               and
               yet
               fill
               the
               Barrel
               more
               exactly
               ,
               than
               before
               ,
               )
               I
               order'd
               (
               being
               to
               be
               absent
               for
               a
               while
               my self
               )
               that
               the
               Pipe
               should
               be
               fill'd
               with
               spirit
               of
               Wine
               tincted
               with
               Cocheneel
               ,
               that
               the
               liquor
               and
               its
               motions
               might
               be
               the
               better
               discern'd
               ,
               and
               that
               the
               Pipe
               being
               fill'd
               ,
               that
               Air
               might
               be
               excluded
               ,
               which
               vvould
               else
               be
               harboured
               in
               the
               Pipe
               ,
               (
               which
               Caution
               was
               omitted
               in
               the
               foregoing
               Experiment
               .
               )
               And
               this
               the
               Person
               ,
               to
               whom
               I
               committed
               it
               ,
               affirm'd
               to
               have
               been
               carefully
               done
               ,
               though
               when
               he
               inverted
               the
               Pipe
               thus
               fill'd
               into
               the
               rest
               of
               the
               red
               Liquor
               ,
               that
               was
               put
               into
               a
               Viol
               ,
               he
               could
               not
               possibly
               do
               it
               so
               well
               ,
               but
               that
               a
               bubble
               of
               Air
               got
               into
               the
               Pipe
               ,
               and
               took
               up
               some
               (
               though
               but
               a
               litle
               )
               room
               there
               .
               By
               that
               time
               ,
               I
               was
               call'd
               upon
               ,
               to
               see
               
               the
               Event
               of
               the
               Tryal
               ,
               and
               could
               come
               to
               look
               upon
               it
               ,
               the
               Receiver
               was
               almost
               quite
               exhausted
               ;
               vvherefore
               after
               I
               had
               made
               the
               pumping
               be
               continued
               a
               litle
               longer
               ,
               and
               perceived
               that
               the
               tincted
               spirit
               was
               fallen
               down
               out
               of
               the
               Pipe
               ,
               and
               that
               which
               lay
               in
               the
               Viol
               seem'd
               almost
               to
               boyl
               at
               the
               top
               ,
               by
               reason
               of
               the
               emersion
               of
               numerous
               Bubbles
               ,
               I
               caus'd
               the
               Sucker
               to
               be
               ,
               by
               the
               help
               of
               the
               Turning-key
               ,
               drawn
               up
               (
               by
               our
               aestimate
               )
               about
               two
               inches
               and
               a
               half
               ,
               notwithstanding
               which
               vve
               could
               not
               perceive
               the
               spirit
               of
               Wine
               to
               rise
               in
               the
               Pipe
               ,
               (
               though
               the
               Pumping
               were
               before
               left
               off
               .
               )
               For
               vvhich
               reason
               I
               order'd
               the
               Air
               to
               be
               let
               in
               very
               leisurely
               ,
               upon
               which
               vve
               could
               plainly
               see
               that
               the
               red
               spirit
               was
               quickly
               driven
               up
               to
               the
               top
               of
               the
               Pipe
               ,
               and
               that
               it
               was
               so
               likewise
               into
               the
               Cavity
               of
               the
               Barrel
               ,
               appeared
               ,
               when
               the
               Receiver
               was
               removed
               ,
               by
               the
               small
               Quantity
               of
               Liquor
               that
               remained
               in
               the
               viol
               ,
               and
               the
               plenty
               of
               it
               which
               came
               out
               of
               the
               Syringe
               .
            
             
               NB.
               That
               if
               I
               had
               not
               vvanted
               dexterous
               Artificers
               ,
               to
               work
               according
               to
               a
               Contrivance
               I
               had
               design'd
               ,
               I
               had
               attempted
               to
               imitate
               ,
               by
               the
               help
               of
               the
               bare
               Spring
               of
               the
               Air
               ,
               such
               Experiments
               ,
               as
               in
               the
               lately
               recited
               Tryals
               vvere
               made
               to
               succeed
               ,
               by
               the
               help
               of
               the
               Pressure
               exercis'd
               by
               the
               Air
               upon
               the
               account
               of
               its
               Weight
               .
            
          
        
         
           
             EXPERIMENT
             XXXV
             .
          
           
             Shewing
             ,
             that
             upon
             the
             Pressure
             of
             the
             Air
             depends
             the
             sticking
             of
             Cupping
             Glasses
             to
             the
             fleshy
             parts
             they
             are
             apply'd
             to
             .
          
           
             T
             Is
             sufficiently
             known
             ,
             that
             if
             the
             Air
             within
             a
             Cupping
             Glass
             be
             rarified
             by
             the
             flame
             of
             Tow
             ,
             Flax
             ,
             or
             the
             like
             ,
             (
             burn'd
             for
             a
             litle
             while
             in
             it
             ,
             )
             and
             the
             Glass
             be
             presently
             clapt
             upon
             some
             fleshy
             part
             of
             a
             Mans
             body
             ,
             there
             will
             quickly
             ensue
             a
             painful
             and
             visible
             swelling
             of
             the
             part
             cover'd
             by
             the
             Cupping
             Glass
             .
          
           
           
             T
             is
             also
             known
             ,
             that
             this
             Experiment
             is
             wont
             to
             be
             urg'd
             by
             the
             Schools
             as
             a
             clear
             proof
             of
             that
             abhorrence
             of
             a
             Vacuum
             they
             ascribe
             to
             Nature
             ;
             for
             ,
             say
             they
             ,
             the
             reason
             of
             this
             phaenomenon
             is
             plainly
             ,
             that
             the
             internal
             Air
             of
             the
             Cupping
             Glass
             ,
             praeternaturally
             rarified
             by
             heat
             when
             the
             Instrument
             is
             applied
             ,
             That
             heat
             after
             a
             while
             ceasing
             ,
             the
             succeeding
             Cold
             must
             again
             necessarily
             condense
             the
             Air
             ;
             and
             so
             this
             contracted
             Air
             being
             no
             longer
             able
             to
             fill
             the
             whole
             space
             it
             replenished
             before
             ,
             there
             would
             ensue
             a
             vacuum
             ,
             if
             the
             flesh
             covered
             by
             the
             Cupping
             Glass
             ,
             or
             adjoyning
             to
             it
             ,
             did
             not
             swell
             into
             the
             Cavity
             of
             it
             ,
             to
             fill
             the
             place
             deserted
             by
             the
             Air.
             
          
           
             Those
             Moderns
             that
             assert
             the
             Weight
             of
             the
             Atmosphere
             ,
             do
             thence
             ingeniously
             endeavour
             to
             deduce
             the
             phaenomenon
             .
             And
             indeed
             if
             to
             their
             Hypothesis
             about
             the
             Airs
             Weight
             ,
             the
             consideration
             of
             its
             Spring
             be
             added
             ,
             't
             will
             be
             easie
             enough
             to
             explicate
             the
             phaenomenon
             ,
             by
             saying
             ,
             That
             when
             the
             Cupping
             Glass
             is
             first
             set
             on
             ,
             though
             much
             of
             the
             Air
             it
             formerly
             contain'd
             were
             a
             litle
             before
             expell'd
             by
             the
             heat
             ,
             yet
             the
             same
             heat
             ,
             increasing
             the
             pressure
             of
             the
             remaining
             Air
             ,
             is
             the
             cause
             that
             the
             absence
             of
             the
             Air
             driven
             out
             of
             the
             Glass
             ,
             does
             not
             immediately
             occasion
             so
             sensible
             a
             pain
             :
             but
             ,
             when
             that
             adventitious
             agitation
             of
             the
             included
             Air
             ceases
             ,
             that
             Air
             having
             now
             ,
             because
             of
             the
             paucity
             of
             its
             Corpuscles
             ,
             but
             a
             weak
             Spring
             ,
             can
             no
             longer
             press
             upon
             the
             part
             covered
             by
             the
             Cupping
             Glass
             neer
             so
             strongly
             ,
             as
             the
             outward
             Air
             does
             by
             its
             Weight
             press
             upon
             all
             the
             neighbouring
             parts
             of
             the
             flesh
             :
             by
             which
             means
             (
             according
             to
             what
             we
             have
             more
             than
             once
             explicated
             already
             )
             some
             of
             the
             yielding
             flesh
             (
             or
             other
             body
             covered
             by
             the
             skin
             )
             must
             be
             forceably
             thrust
             into
             the
             cavity
             of
             the
             Cupping
             Glass
             ,
             where
             there
             is
             less
             Pressure
             ,
             then
             at
             the
             outside
             of
             it
             .
             And
             the
             fibres
             and
             membranous
             parts
             being
             thus
             violently
             stretcht
             ,
             there
             must
             needs
             follow
             a
             sensible
             Pain
             as
             well
             as
             Tumour
             .
             Which
             Tumour
             yet
             does
             not
             fill
             up
             the
             Cupping
             Glass
             ,
             not
             onely
             because
             of
             the
             resistance
             of
             the
             skin
             to
             be
             so
             far
             distended
             ,
             but
             also
             ,
             if
             the
             included
             Air
             have
             not
             been
             much
             rarified
             
             because
             of
             the
             Spring
             of
             the
             imprisoned
             Air
             ,
             (
             which
             grows
             so
             much
             the
             stronger
             ,
             by
             how
             much
             the
             swelling
             flesh
             reduces
             the
             Air
             into
             less
             room
             ,
             )
             as
             I
             have
             sometimes
             tried
             ,
             by
             applying
             a
             Cupping
             Glass
             to
             Quick-silver
             ,
             or
             even
             to
             Water
             ,
             which
             will
             rise
             in
             it
             but
             to
             a
             certain
             height
             .
          
           
             But
             though
             by
             this
             ,
             or
             some
             such
             Explication
             ,
             the
             Argument
             urged
             by
             the
             Schools
             in
             favour
             of
             the
             
               fuga
               vacui
            
             may
             be
             sufficiently
             enervated
             ;
             yet
             it
             suited
             better
             with
             the
             design
             of
             this
             Treatise
             to
             propose
             some
             new
             Experiment
             ,
             to
             illustrate
             our
             Hypothesis
             ;
             and
             though
             it
             seem'd
             to
             be
             far
             more
             difficult
             to
             do
             it
             in
             reference
             to
             Cupping
             Glasses
             ,
             than
             to
             other
             subjects
             ,
             yet
             I
             pitcht
             upon
             two
             different
             wayes
             of
             Experimenting
             ;
             whose
             success
             not
             disappointing
             me
             ,
             I
             shall
             now
             give
             Your
             Lordship
             an
             account
             of
             them
             ,
          
           
             We
             took
             a
             Glass
             of
             about
             one
             Inch
             and
             a
             half
             in
             Diameter
             ,
             but
             a
             good
             deal
             longer
             ,
             than
             an
             ordinarily
             shap'd
             Cupping
             Glass
             of
             that
             breadth
             would
             have
             been
             ,
             that
             there
             might
             be
             the
             more
             room
             for
             the
             flame
             to
             burn
             in
             it
             ,
             and
             rarifie
             the
             Air.
             We
             also
             provided
             a
             Receiver
             shap'd
             almost
             like
             a
             Pear
             ,
             this
             Receiver
             was
             open
             at
             both
             ends
             ;
             at
             the
             sharper
             whereof
             there
             was
             but
             a
             small
             orifice
             ,
             but
             at
             the
             obtuse
             end
             there
             rose
             up
             a
             short
             neck
             ,
             whose
             Orifice
             was
             wide
             enough
             to
             admit
             with
             ease
             the
             newly
             mentioned
             Cupping
             Glass
             without
             touching
             the
             sides
             of
             it
             ,
             and
             we
             were
             not
             willing
             it
             should
             be
             much
             larger
             ,
             lest
             it
             should
             not
             be
             so
             exactly
             cover'd
             by
             the
             Palm
             of
             the
             hand
             that
             should
             be
             laid
             upon
             it
             ,
             and
             lest
             also
             the
             hand
             should
             be
             broken
             or
             hurt
             by
             the
             too
             great
             weight
             of
             the
             Atmosphere
             ,
             when
             the
             included
             Air
             should
             be
             withdrawn
             from
             under
             it
             .
          
           
             These
             things
             being
             thus
             prepared
             ,
             and
             the
             smaller
             Orifice
             of
             the
             Receiver
             being
             fastned
             with
             Cement
             to
             the
             Engine
             ,
             I
             caused
             the
             Cupping
             Glass
             to
             be
             fastned
             ,
             with
             the
             mouth
             upwards
             ,
             to
             the
             Palm
             of
             the
             hand
             of
             a
             Youth
             ,
             (
             whom
             your
             Lordship
             may
             remember
             to
             have
             seen
             with
             me
             ,
             )
             whose
             hand
             seem'd
             fram'd
             by
             Nature
             for
             this
             Experiment
             ,
             being
             broad
             ,
             strong
             ,
             and
             very
             plump
             .
             And
             
             having
             pull'd
             the
             Glass
             ,
             to
             try
             whether
             it
             stuck
             well
             on
             ,
             I
             caus'd
             him
             to
             put
             it
             into
             the
             Receiver
             ,
             and
             lay
             his
             hand
             so
             upon
             the
             Orifice
             lately
             mentioned
             ,
             that
             it
             might
             serve
             for
             a
             Cover
             to
             it
             ,
             and
             hinder
             any
             Air
             from
             getting
             in
             between
             them
             .
          
           
             That
             which
             we
             pretended
             was
             ,
             that
             the
             Receiver
             being
             but
             small
             ,
             (
             that
             it
             might
             be
             quickly
             exhausted
             ,
             and
             so
             not
             put
             the
             Youth
             to
             a
             long
             pain
             ,
             )
             upon
             an
             Exuction
             or
             two
             made
             with
             the
             Pump
             ,
             of
             the
             Air
             about
             the
             Cupping
             Glass
             ,
             the
             remaining
             Air
             should
             have
             its
             Pressure
             so
             far
             weakned
             ,
             as
             not
             to
             be
             able
             to
             support
             the
             Cupping
             Glass
             ;
             especially
             since
             if
             the
             Air
             without
             the
             Cupping
             Glass
             (
             but
             yet
             in
             the
             Receiver
             )
             should
             be
             more
             rarified
             by
             the
             removal
             of
             that
             which
             had
             been
             pump'd
             out
             ,
             than
             the
             Air
             included
             in
             the
             Cupping
             Glass
             was
             by
             the
             precedent
             Heat
             ;
             this
             last
             mentioned
             Air
             having
             a
             stronger
             Spring
             (
             or
             tendency
             to
             expand
             it self
             )
             than
             the
             External
             Air
             of
             the
             Receiver
             ,
             the
             Glass
             must
             needs
             fall
             down
             ,
             or
             rather
             be
             thrust
             off
             ,
             though
             ,
             in
             case
             there
             had
             been
             no
             Air
             at
             all
             left
             in
             the
             Cavity
             of
             the
             Cupping
             Glass
             ,
             the
             Air
             in
             the
             Receiver
             would
             by
             its
             Pressure
             sustain
             a
             far
             Greater
             weight
             .
          
           
             The
             Event
             of
             our
             Trial
             agreed
             very
             well
             with
             our
             conjecture
             .
             For
             upon
             the
             first
             Suck
             the
             Cupping
             Glass
             fell
             off
             ,
             the
             weight
             of
             the
             Atmosphere
             pressing
             so
             hard
             upon
             the
             Young
             mans
             hand
             ,
             that
             ,
             though
             he
             be
             more
             than
             ordinary
             strong
             ,
             he
             complain'd
             he
             could
             very
             hardly
             take
             it
             off
             the
             Glass
             it
             was
             almost
             thrust
             into
             ,
             and
             ,
             a
             while
             after
             ,
             that
             his
             hand
             was
             very
             sore
             .
             But
             this
             last
             inconvenience
             became
             not
             so
             quickly
             very
             sensible
             ,
             but
             that
             we
             had
             time
             to
             repeat
             our
             Experiment
             ,
             by
             fastning
             the
             Cupping
             Glass
             more
             strongly
             than
             before
             ;
             so
             that
             he
             complain'd
             that
             it
             drew
             in
             his
             hand
             very
             forceably
             ,
             and
             though
             that
             part
             be
             not
             wont
             to
             be
             fleshy
             ,
             yet
             the
             Tumour
             occasioned
             by
             the
             Cupping
             Glass
             was
             manifest
             enough
             to
             the
             eye
             :
             but
             as
             before
             ,
             so
             now
             ,
             at
             the
             very
             first
             turning
             of
             the
             Stop-cock
             ,
             (
             to
             let
             out
             the
             Air
             of
             the
             Receiver
             ,
             )
             the
             Cupping
             Glass
             fell
             off
             .
          
        
         
           
           
             EXPERIMENT
             XXXVI
             .
          
           
             About
             the
             making
             ,
             without
             heat
             ,
             a
             Cupping
             Glass
             to
             lift
             up
             a
             great
             Weight
             .
          
           
             THe
             other
             Experiment
             I
             lately
             told
             Your
             Lordship
             we
             had
             made
             ,
             to
             illustrate
             our
             Doctrine
             about
             the
             cause
             of
             the
             sticking
             of
             applied
             Cupping
             Glasses
             ,
             was
             tried
             after
             the
             following
             manner
             .
          
           
             We
             took
             the
             Brass-hoop
             or
             Ring
             ,
             mentioned
             in
             the
             5
             th
             and
             6
             th
             Experiments
             ,
             and
             cover'd
             it
             with
             a
             Bladder
             ,
             (
             which
             was
             wetted
             to
             make
             it
             the
             more
             limber
             ,
             )
             and
             was
             so
             tied
             on
             to
             it
             ,
             (
             which
             was
             easie
             to
             do
             ,
             )
             that
             the
             bottom
             of
             the
             Bladder
             covered
             the
             upper
             orifice
             of
             the
             Hoop
             ,
             and
             was
             stretcht
             (
             though
             not
             strongly
             )
             upon
             it
             ,
             almost
             like
             the
             Membrane
             that
             makes
             the
             head
             of
             a
             Drumm
             ;
             and
             the
             neck
             of
             the
             Bladder
             was
             tied
             with
             a
             string
             near
             the
             middle
             of
             the
             lower
             Orifice
             of
             the
             Hoop
             ,
             and
             in
             this
             lower
             part
             of
             the
             Bladder
             we
             made
             two
             or
             three
             small
             Holes
             for
             the
             Air
             to
             pass
             in
             and
             out
             at
             .
             Then
             having
             plac'd
             at
             the
             bottom
             of
             the
             often
             mentioned
             capp'd
             Receiver
             a
             thick
             piece
             of
             Wood
             ,
             that
             had
             a
             hole
             in
             it
             ,
             to
             receive
             the
             neck
             of
             the
             Bladder
             ,
             we
             so
             plac'd
             the
             cover'd
             Hoop
             upon
             this
             piece
             of
             Wood
             ,
             that
             the
             upper
             part
             of
             the
             Bladder
             lay
             parallel
             to
             the
             Horizon
             .
             This
             done
             ,
             we
             suspended
             ,
             at
             the
             Turning-key
             belonging
             to
             the
             Cap
             of
             our
             Receiver
             ,
             a
             blind
             head
             (
             as
             Chymists
             call
             it
             )
             of
             Glass
             ,
             which
             for
             want
             of
             a
             true
             Cupping
             Glass
             we
             were
             fain
             to
             substitute
             ,
             and
             which
             indeed
             was
             not
             very
             unlike
             one
             either
             for
             shape
             or
             size
             ;
             and
             to
             the
             upper
             part
             of
             this
             Glass
             we
             fastned
             a
             large
             Ring
             of
             Metal
             ,
             the
             better
             to
             depress
             it
             ,
             and
             make
             it
             lean
             strongly
             on
             the
             Bladder
             .
          
           
             These
             things
             being
             thus
             made
             ready
             ,
             and
             the
             Receiver
             cemented
             on
             to
             the
             Engine
             ,
             we
             did
             by
             help
             of
             the
             Turning-key
             let
             down
             the
             Cupping
             Glass
             ,
             (
             for
             so
             we
             shall
             hereafter
             call
             it
             ,
             )
             till
             it
             came
             almost
             to
             touch
             the
             level
             Superficies
             of
             the
             Bladder
             ;
             and
             
             when
             the
             Receiver
             was
             as
             far
             exhausted
             as
             we
             thought
             fit
             ,
             (
             but
             not
             near
             as
             far
             as
             it
             might
             have
             been
             ,
             )
             we
             let
             down
             the
             Cupping
             Glass
             a
             litle
             lower
             ,
             so
             that
             it
             lean'd
             upon
             the
             Bladder
             ,
             and
             touch'd
             it
             with
             all
             the
             parts
             of
             its
             orifice
             :
             so
             that
             the
             Cupping
             Glass
             with
             the
             subjacent
             Bladder
             was
             become
             an
             internal
             Receiver
             (
             if
             I
             may
             so
             call
             it
             ,
             )
             whose
             Air
             was
             considerably
             expanded
             ,
             and
             consequently
             weakned
             as
             to
             its
             Spring
             .
             All
             this
             being
             done
             ,
             we
             warily
             let
             the
             Air
             into
             the
             Receiver
             ,
             and
             thereby
             the
             Air
             ,
             that
             did
             surround
             the
             Cupping
             Glass
             ,
             (
             which
             we
             just
             now
             called
             the
             Internal
             Receiver
             ,
             )
             having
             now
             a
             stronger
             Pressure
             than
             the
             Air
             in
             the
             Cupping
             Glass
             could
             resist
             ;
             the
             Bladder
             ,
             on
             which
             the
             Cupping
             Glass
             rested
             ,
             was
             as
             we
             look'd
             for
             ,
             thrust
             up
             a
             pretty
             way
             into
             the
             cavity
             of
             the
             Glass
             ,
             in
             which
             it
             made
             a
             conspicuous
             Tumor
             ;
             and
             was
             made
             to
             stick
             so
             close
             to
             the
             orifice
             of
             it
             ,
             that
             one
             would
             have
             thought
             that
             the
             Bladder
             had
             been
             violently
             drawn
             in
             ,
             as
             the
             skin
             is
             wont
             to
             be
             in
             the
             ordinary
             applications
             of
             Cupping
             Glasses
             .
          
           
             And
             because
             we
             took
             notice
             ,
             that
             though
             this
             Glass
             were
             not
             capacious
             ,
             (
             for
             it
             scarce
             held
             a
             Pint
             of
             Water
             ,
             )
             yet
             the
             orifice
             of
             it
             was
             not
             very
             narrow
             ,
             (
             being
             in
             Diameter
             an
             inch
             and
             ⅘
             ,
             )
             we
             thought
             fit
             in
             repeating
             the
             Experiment
             to
             adde
             something
             that
             seem'd
             odd
             enough
             ,
             and
             was
             fit
             to
             manifest
             that
             Cupping
             Glasses
             may
             ,
             without
             heat
             ,
             by
             the
             bare
             Pressure
             of
             the
             external
             Air
             ,
             be
             more
             strongly
             fastned
             ,
             than
             for
             ought
             we
             know
             they
             are
             by
             the
             help
             of
             flame
             .
             Having
             then
             reiterated
             the
             former
             Experiment
             with
             this
             onely
             variation
             ,
             that
             we
             exhausted
             the
             Receiver
             further
             than
             before
             ,
             we
             took
             out
             the
             Cupping
             Glass
             and
             the
             Bladder
             ,
             which
             together
             with
             the
             included
             Brass-hoop
             was
             hanging
             at
             it
             ;
             and
             then
             having
             tied
             the
             Glass
             to
             the
             Hook
             of
             a
             good
             Statera
             ,
             and
             tied
             a
             large
             Scale
             to
             the
             neck
             of
             the
             Bladder
             ,
             we
             put
             in
             by
             degrees
             Weights
             into
             the
             Scale
             ,
             till
             we
             had
             loaded
             it
             enough
             to
             force
             off
             the
             Bladder
             from
             the
             Glass
             ;
             which
             hapned
             not
             till
             the
             whole
             Weight
             ,
             that
             tended
             to
             draw
             down
             the
             Bladder
             ,
             amounted
             to
             35
             Pound
             (
             if
             not
             better
             ,
             )
             of
             sixteen
             ounces
             in
             the
             pound
             .
             Nor
             did
             
             we
             doubt
             ,
             but
             that
             the
             Pressure
             of
             the
             Atmosphere
             would
             in
             our
             Experiment
             have
             kept
             up
             a
             much
             greater
             Weight
             ,
             if
             we
             had
             ,
             before
             we
             let
             in
             the
             outward
             Air
             ,
             diligently
             exhausted
             the
             Receiver
             ;
             which
             we
             had
             purposely
             forborn
             to
             do
             ,
             for
             fear
             the
             too
             disproportionate
             Pressure
             of
             the
             external
             Air
             should
             break
             the
             Bladder
             :
             which
             puts
             me
             in
             mind
             of
             adding
             ,
             upon
             the
             by
             ,
             That
             as
             more
             Weight
             was
             put
             into
             the
             Scale
             ,
             the
             Bladder
             (
             stretcht
             more
             and
             more
             by
             the
             Weight
             on
             one
             side
             ,
             and
             the
             Air
             on
             the
             other
             ,
             )
             appear'd
             to
             swell
             higher
             in
             the
             cavity
             of
             the
             Glass
             .
          
        
         
           
             EXPERIMENT
             XXXVII
             .
          
           
             Shewing
             ,
             that
             Bellows
             ,
             whose
             Nose
             is
             very
             well
             stopt
             ,
             will
             open
             of
             themselves
             ,
             when
             the
             Pressure
             of
             the
             external
             Air
             is
             taken
             off
             .
          
           
             IT
             is
             wont
             by
             the
             Peripateticks
             and
             others
             to
             be
             made
             a
             great
             argument
             for
             the
             
               fuga
               vacui
            
             which
             they
             attribute
             to
             Nature
             ,
             That
             if
             the
             Nose
             of
             a
             pair
             of
             Bellows
             be
             well
             stopt
             ,
             one
             cannot
             open
             them
             by
             raising
             the
             upper
             board
             from
             the
             lower
             .
             But
             of
             this
             another
             reason
             may
             be
             easily
             assigned
             ,
             without
             determining
             whether
             there
             be
             a
             vacuum
             or
             no
             ,
             namely
             the
             Weight
             and
             Pressure
             of
             the
             Air
             :
             for
             when
             the
             Nose
             of
             a
             pair
             of
             Bellows
             ,
             that
             are
             Tite
             enough
             ,
             is
             well
             stopt
             ,
             no
             Air
             being
             able
             to
             insinuate
             it self
             upon
             the
             disjoining
             of
             the
             boards
             into
             the
             Cavity
             made
             by
             that
             disjunction
             ,
             This
             cannot
             be
             effected
             ,
             but
             by
             such
             a
             force
             as
             is
             almost
             able
             (
             I
             say
             almost
             ,
             because
             ordinary
             Bellows
             cannot
             be
             so
             well
             shut
             ,
             but
             that
             there
             will
             remain
             some
             Air
             in
             them
             ,
             whose
             Spring
             will
             facilitate
             the
             opening
             of
             them
             )
             to
             raise
             an
             Atmosphere
             Pillar
             ,
             whose
             Basis
             shall
             be
             the
             upper
             board
             ,
             vvhich
             is
             commonly
             so
             large
             ,
             that
             a
             less
             force
             may
             serve
             to
             break
             common
             Bellows
             ,
             then
             to
             raise
             so
             great
             a
             Weight
             :
             but
             if
             they
             vvere
             made
             strong
             enough
             ,
             and
             there
             vvere
             applied
             a
             sufficient
             force
             to
             lift
             so
             Great
             a
             vveight
             as
             the
             newly
             mentioned
             Pillar
             of
             the
             Atmosphere
             ,
             the
             sides
             might
             
             be
             disjoyn'd
             ,
             how
             close
             and
             stanch
             soever
             the
             Instrument
             vvere
             made
             .
          
           
             Thus
             far
             one
             may
             argue
             upon
             the
             bare
             principle
             of
             the
             weight
             of
             the
             Air
             ,
             but
             taking
             in
             the
             Spring
             of
             it
             too
             ,
             I
             thought
             one
             might
             proceed
             so
             much
             further
             ,
             that
             I
             ventur'd
             to
             foretell
             divers
             ingenious
             men
             ,
             that
             if
             the
             Pressure
             of
             the
             ambient
             Air
             were
             taken
             off
             ,
             not
             onely
             it
             would
             be
             easie
             to
             open
             the
             Bellows
             in
             spite
             of
             their
             being
             carefully
             stopt
             at
             the
             nose
             ,
             but
             that
             they
             would
             fly
             open
             as
             it
             were
             of
             their
             own
             accord
             ,
             without
             the
             application
             of
             any
             external
             force
             at
             all
             .
             And
             't
             was
             partly
             to
             justifie
             this
             prediction
             ,
             as
             well
             as
             to
             make
             a
             Trial
             ,
             I
             thought
             more
             considerable
             ,
             that
             we
             made
             the
             following
             Experiment
             .
          
           
             We
             caus'd
             (
             then
             )
             to
             be
             made
             a
             pair
             of
             Bellows
             ,
             differing
             from
             ordinary
             ones
             in
             these
             particulars
             .
             First
             ,
             that
             the
             Boards
             were
             circular
             ,
             (
             and
             so
             without
             handles
             ,
             )
             and
             of
             about
             6
             inches
             in
             Diameter
             :
             2.
             
             That
             there
             was
             no
             Clack
             or
             Valve
             :
             3.
             
             That
             the
             nose
             was
             but
             an
             inch
             long
             ,
             or
             less
             ,
             (
             being
             to
             be
             lengthned
             if
             occasion
             required
             vvith
             a
             Pipe
             :
             )
             4.
             
             That
             the
             Leather
             (
             which
             vvas
             not
             spar'd
             ,
             that
             the
             instrument
             might
             be
             the
             more
             capacious
             )
             was
             not
             horny
             or
             very
             stiff
             ,
             but
             limber
             .
             The
             Reason
             of
             the
             first
             and
             third
             diversity
             was
             ,
             that
             the
             Bellows
             might
             be
             capable
             to
             be
             conveyed
             into
             our
             Receiver
             ;
             (
             for
             vvhich
             purpose
             also
             ,
             if
             there
             had
             appear'd
             need
             ,
             the
             nose
             might
             have
             been
             made
             in
             the
             uppermost
             of
             the
             two
             Boards
             :
             )
             the
             reason
             of
             the
             2
             d
             variation
             was
             ,
             that
             the
             instrument
             might
             be
             the
             more
             stanch
             :
             and
             of
             the
             4
             th
             ,
             that
             the
             bases
             of
             the
             Bellows
             might
             (
             as
             in
             Organ-bellows
             )
             be
             clapt
             closer
             together
             ,
             and
             harbour
             less
             Air
             in
             the
             wrinkles
             and
             cavity
             .
             So
             that
             when
             the
             Bellows
             vvere
             opened
             to
             their
             full
             extent
             ,
             by
             drawing
             up
             the
             upper
             Basis
             at
             a
             button
             purposely
             made
             in
             the
             midst
             of
             it
             ,
             the
             Bellows
             look'd
             like
             a
             Cylinder
             of
             16
             or
             18
             inches
             high
             ;
             upon
             which
             resemblance
             I
             take
             the
             liberty
             to
             call
             both
             the
             Boards
             (
             as
             Geometricians
             do
             both
             the
             circular
             parts
             of
             a
             Cylinder
             )
             Bases
             .
          
           
             But
             though
             these
             were
             made
             by
             an
             Artificer
             ,
             otherwise
             dexterous
             ,
             yet
             it
             not
             being
             his
             Trade
             to
             make
             Bellows
             ,
             nor
             any
             other
             
             mans
             in
             the
             Town
             I
             then
             was
             in
             ,
             he
             could
             not
             make
             them
             so
             Tite
             ,
             but
             that
             in
             spite
             of
             our
             oyling
             the
             Leather
             ,
             and
             choaking
             the
             Seams
             with
             good
             Cement
             ,
             there
             was
             some
             litle
             and
             unperceived
             hole
             or
             cranny
             ,
             whereby
             some
             Air
             had
             passage
             when
             the
             nose
             was
             accurately
             stopt
             :
             but
             this
             was
             not
             so
             considerable
             ,
             but
             that
             if
             we
             drew
             up
             the
             upper
             Basis
             from
             the
             lower
             ,
             the
             external
             Air
             would
             on
             all
             sides
             press
             the
             Leather
             inwards
             ,
             and
             so
             make
             the
             shape
             of
             the
             instrument
             very
             far
             from
             being
             so
             Cylindrical
             ,
             as
             it
             would
             be
             if
             the
             nose
             were
             left
             open
             .
          
           
             Wherefore
             concluding
             ,
             that
             notwithstanding
             this
             imperfection
             the
             Bellows
             would
             serve
             ,
             though
             not
             for
             both
             the
             Experiments
             I
             design'd
             ,
             yet
             for
             one
             of
             them
             ,
             we
             carefully
             stopt
             the
             nose
             ,
             after
             we
             had
             approach'd
             the
             Bases
             to
             one
             another
             ,
             and
             conveying
             them
             into
             a
             large
             Receiver
             ,
             it
             quickly
             appear'd
             ,
             when
             the
             Pump
             was
             set
             on
             work
             ,
             that
             at
             every
             Exsuction
             of
             the
             incumbent
             Air
             ,
             the
             Air
             harbour'd
             in
             the
             folds
             of
             the
             Leather
             ,
             and
             the
             rest
             of
             the
             litle
             Cavitie
             that
             could
             not
             but
             be
             left
             between
             the
             Bases
             ,
             made
             the
             upper
             of
             those
             Bases
             manifestly
             rise
             ,
             though
             its
             weight
             (
             because
             of
             the
             thickness
             and
             solidity
             of
             the
             Wood
             )
             would
             soon
             after
             depress
             it
             again
             ,
             either
             by
             driving
             out
             some
             of
             the
             Air
             at
             some
             place
             where
             the
             instrument
             was
             not
             sufficiently
             Tite
             ,
             or
             by
             making
             it
             as
             it
             were
             strain'd
             through
             the
             Leather
             it self
             ;
             and
             if
             the
             Pump
             were
             agitated
             somewhat
             faster
             than
             ordinary
             ,
             the
             Expansion
             of
             the
             internal
             Air
             would
             be
             greater
             than
             could
             be
             rendred
             quite
             ineffectual
             by
             so
             small
             a
             Leak
             ,
             and
             the
             upper
             part
             of
             the
             Bellows
             would
             be
             soon
             rais'd
             to
             a
             considerable
             height
             ,
             as
             would
             appear
             more
             evidently
             if
             we
             hastily
             let
             in
             the
             external
             Air
             ,
             upon
             whose
             ingress
             the
             Bases
             would
             be
             clapt
             together
             ,
             and
             the
             upper
             of
             them
             a
             good
             vvay
             deprest
             .
             So
             that
             the
             imperfection
             of
             the
             Bellows
             made
             the
             Experiment
             rather
             more
             than
             less
             concluding
             ;
             for
             since
             there
             was
             no
             external
             force
             applied
             to
             open
             them
             ,
             if
             notwithstanding
             that
             some
             of
             the
             included
             Air
             could
             get
             out
             of
             thē
             ,
             yet
             the
             Spring
             of
             the
             internal
             Air
             was
             strong
             enough
             to
             open
             the
             Bellows
             when
             the
             ambient
             Air
             was
             withdrawn
             ,
             much
             more
             
             would
             the
             effect
             have
             been
             produc'd
             ,
             if
             the
             Bellows
             had
             been
             perfectly
             stanch
             .
          
        
         
           
             EXPERIMENT
             XXXVIII
             .
          
           
             About
             an
             Attempt
             to
             examine
             the
             Motions
             and
             Sensibility
             of
             the
             Cartesian
             Materia
             subtilis
             ,
             or
             the
             Aether
             ,
             with
             a
             pair
             of
             Bellows
             (
             made
             of
             a
             Bladder
             )
             in
             the
             exhausted
             Receiver
             .
          
           
             I
             Will
             not
             now
             discuss
             the
             Controversie
             betwixt
             some
             of
             the
             Modern
             Atomists
             ,
             and
             the
             Cartesians
             ;
             the
             former
             of
             whom
             think
             ,
             that
             betwixt
             the
             Earth
             and
             the
             Stars
             ,
             and
             betwixt
             these
             themselves
             there
             are
             vast
             Tracts
             of
             Space
             that
             are
             empty
             ,
             save
             where
             the
             beams
             of
             Light
             do
             pass
             through
             them
             ;
             and
             the
             later
             of
             whom
             tell
             us
             ,
             that
             the
             Intervals
             betwixt
             the
             Stars
             and
             Planets
             (
             among
             which
             the
             Earth
             may
             perhaps
             be
             reckon'd
             )
             are
             perfectly
             fill'd
             ,
             but
             by
             a
             Matter
             far
             subtiler
             than
             our
             Air
             ,
             which
             some
             call
             Celestial
             ,
             and
             others
             Aether
             .
             I
             shall
             not
             ,
             I
             say
             ,
             engage
             in
             this
             controversie
             ,
             but
             thus
             much
             seems
             evident
             ,
             That
             if
             there
             be
             such
             a
             Celestial
             Matter
             ,
             it
             must
             make
             up
             far
             the
             Greatest
             part
             of
             the
             Universe
             known
             to
             us
             .
             For
             the
             Intersteller
             part
             of
             the
             world
             (
             if
             I
             may
             so
             stile
             it
             )
             bears
             so
             very
             great
             a
             proportion
             to
             the
             Globes
             ,
             and
             their
             Atmospheres
             too
             ,
             (
             if
             other
             Stars
             have
             any
             as
             well
             as
             the
             Earth
             ,
             )
             that
             it
             is
             almost
             incomparably
             Greater
             in
             respect
             of
             them
             ,
             than
             all
             our
             Atmosphere
             is
             in
             respect
             of
             the
             Clouds
             ,
             not
             to
             make
             the
             comparison
             between
             the
             Sea
             and
             the
             Fishes
             that
             swim
             in
             it
             .
          
           
             Wherefore
             I
             thought
             it
             might
             very
             vvell
             deserve
             a
             heedful
             Enquiry
             ,
             whether
             we
             can
             by
             sensible
             Experiments
             (
             for
             I
             hear
             what
             has
             been
             attempted
             by
             Speculative
             Arguments
             )
             discover
             any
             thing
             about
             the
             Existence
             ,
             or
             the
             Qualifications
             of
             this
             so
             vast
             Aether
             :
             and
             I
             hoped
             our
             Curiosity
             might
             be
             somewhat
             assisted
             by
             our
             Engine
             ,
             if
             I
             could
             manage
             in
             it
             such
             a
             pair
             of
             Bellows
             as
             I
             design'd
             .
             For
             I
             propos'd
             to
             my self
             to
             fasten
             a
             convenient
             weight
             
             to
             the
             upper
             Basis
             ,
             and
             clog
             the
             lower
             with
             another
             ,
             great
             enough
             to
             keep
             it
             Horizontal
             and
             immoveable
             ,
             that
             when
             by
             the
             help
             of
             the
             Turning-key
             ,
             frequently
             above
             mention'd
             ,
             the
             upper
             Basis
             should
             be
             rais'd
             to
             its
             full
             height
             ,
             the
             cavity
             of
             the
             Bellows
             might
             be
             brought
             to
             its
             full
             dimensions
             .
             This
             done
             ,
             I
             intended
             to
             exhaust
             the
             Receiver
             ,
             and
             consequently
             the
             thus
             open'd
             Bellows
             with
             more
             than
             ordinary
             diligence
             ,
             that
             so
             both
             the
             Receiver
             and
             they
             might
             be
             carefully
             freed
             from
             Air.
             After
             vvhich
             I
             purpos'd
             to
             let
             go
             the
             upper
             Base
             of
             the
             Bellows
             ,
             that
             being
             hastily
             deprest
             by
             the
             incumbent
             Weight
             ,
             it
             might
             speedily
             enough
             fall
             down
             to
             the
             lower
             Basis
             ,
             and
             by
             so
             much
             ,
             and
             so
             quickly
             lessening
             the
             Cavity
             ,
             might
             expell
             thence
             the
             Matter
             (
             if
             any
             were
             )
             before
             contain'd
             in
             it
             ,
             and
             that
             (
             if
             it
             could
             by
             this
             way
             be
             done
             )
             at
             the
             hole
             of
             a
             slender
             Pipe
             ,
             fasten'd
             either
             near
             the
             bottom
             of
             the
             Bellows
             ,
             or
             in
             the
             upper
             Basis
             :
             against
             or
             over
             the
             orifice
             of
             which
             Pipe
             there
             was
             to
             be
             plac'd
             at
             a
             convenient
             distance
             either
             a
             Feather
             ,
             or
             (
             if
             that
             should
             prove
             too
             light
             )
             the
             Sail
             of
             a
             litle
             Wind-mill
             made
             of
             Cards
             ,
             or
             some
             other
             light
             body
             ,
             and
             fit
             to
             be
             put
             into
             motion
             by
             the
             impulse
             of
             any
             Matter
             that
             should
             be
             forc'd
             out
             of
             the
             Pipe.
             
          
           
             By
             this
             means
             it
             seem'd
             not
             improbable
             ,
             that
             some
             such
             discovery
             might
             be
             made
             ,
             as
             would
             not
             be
             altogether
             useless
             in
             our
             Enquiry
             .
             For
             if
             notwithstanding
             the
             absence
             of
             the
             Air
             ,
             it
             should
             appear
             by
             the
             Effects
             that
             a
             stream
             of
             other
             Matter
             ,
             capable
             to
             set
             visible
             bodies
             a
             moving
             ,
             should
             issue
             out
             at
             the
             Pipe
             of
             the
             comprest
             Bellows
             ;
             it
             would
             also
             appear
             ,
             that
             there
             may
             be
             a
             much
             subtiller
             Body
             than
             common
             Air
             ,
             and
             as
             yet
             unobserv'd
             by
             the
             Vacuists
             ,
             or
             (
             their
             Adversaries
             )
             the
             Schools
             ,
             that
             may
             even
             copiously
             be
             found
             in
             places
             deserted
             by
             that
             Air
             ;
             and
             that
             it
             is
             not
             safe
             to
             conclude
             from
             the
             absence
             of
             the
             Air
             in
             our
             Receivers
             ,
             and
             in
             the
             upper
             part
             of
             those
             Tubes
             where
             the
             Torricellian
             Experiment
             is
             made
             ,
             that
             there
             is
             no
             other
             body
             left
             but
             an
             absolute
             Vacuity
             ,
             or
             (
             as
             the
             Atomists
             call
             it
             )
             a
             
               vacuū
               coacervatū
            
             .
             But
             if
             on
             the
             other
             side
             there
             should
             appear
             no
             motion
             at
             all
             to
             be
             produc'd
             ,
             
             so
             much
             as
             in
             the
             Feather
             ,
             it
             seem'd
             that
             the
             Vacuists
             might
             plausibly
             argue
             ,
             that
             either
             the
             Cavity
             of
             the
             Bellows
             was
             absolutely
             empty
             ,
             or
             else
             that
             it
             would
             be
             very
             difficult
             to
             prove
             by
             any
             sensible
             Experiment
             that
             it
             was
             full
             ,
             and
             ,
             if
             by
             any
             other
             way
             of
             probation
             it
             be
             demonstrable
             ,
             that
             it
             was
             replenish'd
             with
             Aether
             ,
             we
             that
             have
             not
             yet
             declar'd
             for
             any
             party
             ,
             may
             by
             our
             Experiment
             be
             taught
             to
             have
             no
             confident
             expectations
             of
             easily
             making
             it
             sensible
             by
             Mechanical
             Experiments
             ;
             and
             may
             also
             be
             inform'd
             ,
             that
             t
             is
             really
             so
             subtle
             and
             yielding
             a
             Matter
             ,
             that
             does
             not
             either
             easily
             impell
             such
             light
             bodies
             as
             even
             Feathers
             ,
             or
             sensibly
             resist
             as
             does
             the
             Air
             it self
             the
             motions
             of
             other
             bodies
             through
             it
             ,
             and
             is
             able
             without
             resistance
             to
             make
             its
             passage
             through
             the
             Pores
             of
             Wood
             ,
             and
             Leather
             ,
             and
             also
             of
             closer
             bodies
             ,
             which
             we
             find
             not
             that
             the
             Air
             doth
             in
             its
             Natural
             or
             wonted
             state
             penetrate
             .
          
           
             To
             illustrate
             this
             last
             Clause
             I
             shall
             adde
             ,
             that
             to
             make
             the
             Trial
             more
             accurate
             ,
             I
             wav'd
             the
             use
             of
             other
             Bellows
             ,
             (
             especially
             not
             having
             such
             as
             I
             desired
             ,
             )
             &
             caus'd
             a
             pair
             of
             small
             Bellows
             to
             be
             made
             with
             a
             Bladder
             ,
             as
             a
             Body
             ,
             which
             some
             of
             our
             former
             Experiments
             have
             evinc'd
             to
             be
             of
             so
             close
             a
             Texture
             ,
             that
             Air
             will
             rather
             break
             it
             than
             passe
             through
             it
             :
             and
             that
             the
             Bladder
             might
             no
             where
             loose
             its
             entireness
             by
             Seams
             ,
             we
             glued
             on
             the
             two
             Bases
             ,
             the
             one
             to
             the
             bottom
             ,
             and
             the
             other
             to
             the
             opposite
             part
             of
             it
             ,
             so
             that
             the
             Neck
             came
             out
             at
             a
             hole
             purposely
             made
             for
             it
             ;
             in
             the
             upper
             Basis
             ,
             and
             into
             the
             Neck
             it
             was
             easie
             to
             insert
             what
             pipe
             we
             thought
             fit
             ,
             binding
             the
             Neck
             very
             close
             to
             it
             on
             the
             outside
             .
             We
             had
             likewise
             Thoughts
             to
             have
             another
             pair
             of
             Tite
             Bellows
             made
             with
             a
             very
             light
             Clack
             in
             the
             lower
             Basis
             ,
             that
             by
             hastily
             drawing
             up
             the
             other
             Basis
             ,
             when
             the
             Receiver
             and
             Bellows
             were
             very
             carefully
             exhausted
             ,
             we
             might
             see
             by
             the
             rest
             ,
             as
             the
             lifting
             up
             of
             the
             Clack
             ,
             whether
             the
             subtle
             Matter
             that
             was
             expell'd
             by
             the
             upper
             Basis
             in
             its
             Ascent
             ,
             would
             ,
             according
             to
             the
             Modern
             Doctrine
             of
             the
             Circle
             made
             by
             moving
             Bodies
             ,
             be
             impell'd
             up
             or
             not
             .
          
           
           
             We
             also
             thought
             of
             placing
             the
             litle
             Pipe
             of
             the
             Bladder-bellows
             (
             if
             I
             may
             so
             call
             them
             )
             beneath
             the
             surface
             of
             Water
             exquisitely
             freed
             from
             Air
             ,
             that
             we
             might
             see
             whither
             upon
             the
             Depression
             of
             the
             Bellows
             by
             the
             incumbent
             Weight
             ,
             when
             the
             Receiver
             was
             carefully
             exhausted
             ,
             there
             would
             be
             any
             thing
             expell'd
             at
             the
             Pipe
             ,
             that
             would
             produce
             Bubbles
             in
             the
             liquor
             ,
             wherein
             its
             Orifice
             was
             immerst
             .
          
           
             To
             bring
             now
             our
             Conjectures
             to
             some
             Trial
             ,
             we
             put
             into
             a
             capp'd
             Receiver
             the
             Bladder
             accommodated
             as
             before
             is
             mentioned
             ,
             and
             though
             we
             could
             have
             wish'd
             it
             had
             been
             somewhat
             larger
             ,
             because
             it
             contain'd
             but
             between
             half
             a
             Pint
             and
             a
             Pint
             ,
             yet
             in
             regard
             it
             was
             fine
             and
             limber
             ,
             and
             otherwise
             fit
             for
             our
             Turn
             ,
             we
             resolv'd
             to
             try
             how
             it
             would
             do
             ;
             and
             to
             depress
             the
             upper
             Basis
             of
             these
             litle
             Bellows
             the
             more
             easily
             and
             uniformly
             ,
             we
             cover'd
             the
             round
             piece
             of
             Pastboard
             ,
             that
             made
             the
             upper
             Basis
             ,
             with
             a
             Pewter-plate
             ,
             (
             with
             a
             hole
             in
             it
             for
             the
             neck
             of
             the
             Bladder
             ;
             )
             which
             nevertheless
             upon
             trial
             prov'd
             not
             ponderous
             enough
             ,
             whereby
             we
             were
             oblig'd
             to
             assist
             it
             by
             laying
             on
             it
             a
             Weight
             of
             Lead
             .
             And
             to
             secure
             the
             above
             mentioned
             Feather
             ,
             (
             which
             had
             a
             slender
             and
             flexible
             Stem
             ,
             and
             was
             left
             broad
             at
             one
             end
             ,
             and
             fastned
             by
             Cement
             at
             the
             other
             ,
             so
             as
             to
             stand
             with
             its
             broad
             end
             at
             a
             convenient
             distance
             just
             over
             the
             Orifice
             of
             the
             Pipe
             ,
             )
             from
             being
             blown
             aside
             to
             either
             hand
             ,
             we
             made
             it
             to
             move
             in
             a
             perpendicular
             slit
             in
             a
             piece
             of
             Pastboard
             ,
             
             that
             was
             fastned
             to
             one
             part
             of
             the
             upper
             Basis
             ,
             as
             that
             which
             the
             Feather
             was
             glued
             to
             was
             to
             another
             part
             .
             These
             things
             being
             thus
             provided
             ,
             the
             Pump
             was
             set
             a
             work
             ,
             and
             as
             the
             ambient
             Air
             was
             from
             time
             to
             time
             withdrawn
             ,
             so
             the
             Air
             in
             the
             Bladder
             expanded
             it self
             so
             strongly
             ,
             as
             to
             lift
             up
             the
             metalline
             Weight
             ,
             and
             yet
             in
             part
             to
             sally
             out
             at
             the
             litle
             Glass-pipe
             of
             our
             Bellows
             ,
             as
             appear'd
             by
             its
             blowing
             up
             the
             Feather
             ,
             and
             keeping
             it
             suspended
             till
             the
             Spring
             of
             the
             Air
             in
             the
             bladder
             was
             too
             far
             weakned
             to
             continue
             to
             do
             as
             it
             had
             done
             .
             In
             the
             mean
             time
             we
             did
             now
             and
             then
             ,
             by
             the
             help
             of
             a
             string
             fasten'd
             to
             the
             Turning-key
             ,
             and
             the
             upper
             Basis
             of
             the
             Bellows
             ,
             let
             
             down
             that
             Basis
             a
             litle
             ,
             to
             observe
             how
             upon
             its
             sinking
             the
             blast
             against
             the
             Feather
             would
             decrease
             ,
             as
             the
             Receiver
             was
             further
             and
             further
             exhausted
             .
             And
             when
             we
             judg'd
             it
             to
             be
             sufficiently
             freed
             from
             Air
             ,
             we
             then
             let
             down
             the
             Weight
             ,
             but
             could
             not
             perceive
             that
             by
             shutting
             of
             the
             Bellows
             the
             Feather
             was
             at
             all
             blown
             up
             ,
             as
             it
             had
             been
             wont
             to
             be
             ,
             though
             the
             upper
             Basis
             were
             more
             than
             usually
             deprest
             .
             And
             yet
             it
             seems
             somewhat
             odd
             ,
             that
             when
             ,
             for
             Curiosity
             ,
             in
             order
             to
             a
             further
             Trial
             ,
             the
             Weight
             was
             drawn
             up
             again
             ,
             as
             the
             upper
             basis
             was
             rais'd
             from
             the
             lower
             ,
             the
             sides
             of
             the
             Bladder
             were
             sensibly
             (
             though
             not
             very
             much
             )
             prest
             ,
             or
             drawn
             inwards
             .
             The
             Bellows
             being
             thus
             opened
             ,
             we
             let
             down
             the
             upper
             basis
             again
             ,
             but
             could
             not
             perceive
             that
             any
             blast
             was
             produc'd
             ;
             for
             though
             the
             Feather
             ,
             that
             lay
             just
             over
             and
             near
             the
             orifice
             of
             the
             litle
             Glass
             Pipe
             ,
             had
             some
             motion
             ,
             yet
             this
             seem'd
             plainly
             to
             be
             but
             a
             shaking
             and
             almost
             vibrating
             motion
             (
             to
             the
             right
             and
             left
             hand
             ,
             )
             which
             it
             was
             put
             into
             by
             the
             upper
             basis
             ,
             which
             the
             string
             kept
             from
             a
             smooth
             and
             uniform
             descent
             ;
             but
             not
             to
             proceed
             from
             any
             blast
             issuing
             out
             of
             the
             cavity
             of
             the
             Bladder
             .
             And
             for
             further
             satisfaction
             we
             caus'd
             some
             Air
             to
             be
             let
             into
             the
             Receiver
             ,
             because
             there
             was
             a
             possibility
             ,
             that
             unawares
             to
             us
             the
             slender
             Pipe
             might
             by
             some
             accident
             be
             choak'd
             ;
             but
             though
             upon
             the
             return
             of
             the
             Air
             into
             the
             Receiver
             ,
             the
             bases
             of
             the
             Bellows
             were
             prest
             closer
             together
             ,
             yet
             it
             seem'd
             that
             ,
             according
             to
             our
             Expectation
             ,
             some
             litle
             Air
             got
             through
             the
             Pipe
             into
             the
             cavity
             of
             the
             Bladder
             :
             for
             when
             we
             began
             to
             vvithdraw
             again
             the
             Air
             we
             had
             let
             into
             the
             Receiver
             ,
             the
             Bladder
             began
             to
             swell
             again
             ,
             and
             upon
             our
             letting
             down
             the
             Weight
             ,
             to
             blow
             up
             and
             keep
             up
             the
             Feather
             ,
             as
             had
             been
             done
             before
             the
             Receiver
             had
             been
             so
             well
             exhausted
             .
             What
             conjecture
             the
             opening
             and
             shutting
             of
             our
             litle
             Bellows
             ,
             more
             than
             once
             or
             twice
             ,
             without
             procducing
             any
             blast
             sensible
             by
             the
             raising
             of
             the
             Feather
             ,
             gave
             some
             of
             the
             by-standers
             ,
             may
             be
             easily
             guess'd
             by
             the
             preamble
             of
             this
             Experiment
             ;
             but
             whilst
             I
             was
             endeavouring
             to
             prosecute
             it
             for
             my
             own
             further
             information
             ,
             a
             mischance
             that
             befell
             
             the
             Instrument
             ,
             kept
             me
             from
             giving
             my self
             the
             desir'd
             satisfaction
             .
          
        
         
           
             EXPERIMENT
             XXXIX
             .
          
           
             About
             a
             further
             attempt
             to
             prosecute
             the
             Inquiry
             propos'd
             in
             the
             foregoing
             Experiment
             .
          
           
             COnsidering
             with
             my self
             ,
             that
             by
             the
             help
             of
             some
             contrivances
             not
             difficult
             ,
             a
             Syringe
             might
             be
             made
             to
             serve
             ,
             as
             far
             as
             our
             present
             occasion
             required
             ,
             in
             stead
             of
             a
             pair
             of
             Bellows
             ;
             I
             thought
             it
             would
             not
             be
             improper
             to
             try
             a
             differing
             ,
             and
             ,
             in
             some
             regards
             ,
             a
             better
             way
             to
             prosecute
             an
             attempt
             ,
             which
             seem'd
             to
             me
             to
             deserve
             our
             Curiosity
             .
          
           
             I
             caus'd
             then
             to
             be
             made
             ,
             
             for
             the
             formerly
             mentioned
             Syringe
             ,
             in
             stead
             of
             its
             streight
             Pipe
             ,
             a
             crooked
             one
             ;
             whose
             shorter
             Leg
             was
             parallel
             to
             the
             longer
             .
             And
             this
             Pipe
             was
             for
             greater
             closeness
             ,
             after
             't
             was
             screw'd
             on
             carefully
             ,
             fastned
             with
             Cement
             to
             the
             Barrel
             ;
             and
             because
             the
             Brass-pipe
             could
             scarce
             be
             made
             small
             enough
             ,
             we
             caus'd
             a
             short
             and
             very
             slender
             Pipe
             of
             Glass
             to
             be
             put
             into
             the
             orifice
             of
             the
             shorter
             Leg
             ,
             and
             diligently
             fasten'd
             to
             it
             with
             close
             Cement
             .
             Then
             we
             caus'd
             the
             Sucker
             (
             by
             the
             help
             of
             Oyl
             ,
             Water
             ,
             and
             moving
             it
             up
             and
             down
             )
             to
             be
             made
             to
             go
             as
             smoothly
             as
             might
             be
             ,
             without
             lessening
             the
             stanchness
             of
             the
             Syringe
             .
             After
             this
             ,
             there
             was
             fastned
             to
             the
             handle
             of
             the
             Rammer
             a
             Weight
             ,
             made
             in
             the
             form
             of
             a
             Ring
             ,
             or
             Hoop
             ,
             which
             by
             reason
             of
             its
             figure
             might
             be
             suspended
             from
             the
             newly
             mention'd
             handle
             of
             the
             Rammer
             ,
             and
             hang
             loose
             on
             the
             outside
             of
             the
             Cylinder
             ,
             and
             which
             both
             by
             its
             Figure
             and
             its
             Weight
             might
             evenly
             and
             swiftly
             enough
             depress
             the
             Sucker
             ,
             when
             That
             being
             drawn
             up
             the
             Weight
             should
             be
             let
             go
             .
             This
             Syringe
             thus
             furnished
             ,
             was
             fastned
             to
             a
             broad
             and
             heavy
             Pedestal
             ,
             to
             keep
             it
             in
             its
             vertical
             posture
             ,
             and
             to
             hinder
             it
             from
             Tottering
             ,
             notwithstanding
             the
             Weight
             that
             clogg'd
             it
             .
             And
             besides
             all
             these
             things
             ,
             there
             
             was
             taken
             a
             Feather
             ,
             which
             was
             about
             two
             inches
             long
             ,
             and
             of
             which
             there
             was
             left
             at
             the
             end
             a
             piece
             about
             the
             breadth
             of
             a
             mans
             Thumb-naile
             ,
             (
             the
             rest
             on
             either
             side
             of
             the
             slender
             stalk
             (
             if
             I
             may
             so
             call
             it
             )
             being
             stript
             off
             )
             to
             cover
             the
             hole
             of
             the
             slender
             Glass
             pipe
             of
             the
             Syringe
             ;
             for
             which
             purpose
             the
             other
             extreme
             of
             it
             was
             so
             fastned
             with
             Cement
             to
             the
             lower
             part
             of
             the
             Syring
             ,
             (
             or
             to
             its
             Pedestal
             ,
             )
             that
             the
             broad
             end
             of
             the
             Feather
             was
             plac'd
             (
             as
             the
             other
             Feather
             was
             in
             the
             foregoing
             Experiment
             )
             just
             over
             the
             litle
             orifice
             of
             the
             Glass
             ,
             at
             such
             a
             convenient
             distance
             ,
             that
             when
             the
             Sucker
             was
             a
             litle
             (
             though
             but
             very
             litle
             )
             drawn
             up
             and
             let
             go
             again
             ,
             the
             Weight
             would
             depress
             it
             fast
             enough
             to
             blow
             up
             the
             broad
             part
             of
             the
             Feather
             ,
             as
             high
             as
             was
             permitted
             by
             the
             resistance
             of
             the
             Stalk
             ,
             (
             and
             that
             was
             a
             good
             way
             ,
             )
             the
             Spring
             of
             which
             would
             presently
             restore
             the
             whole
             Feather
             to
             its
             former
             position
             .
          
           
             All
             these
             things
             being
             done
             ,
             and
             the
             handle
             of
             the
             Rammer
             being
             tied
             to
             the
             Turning-key
             of
             a
             capp'd
             Receiver
             ,
             the
             Syringe
             and
             its
             Pedestal
             were
             inclosed
             in
             a
             capacious
             Receiver
             ,
             (
             for
             none
             but
             such
             a
             one
             could
             contain
             them
             ,
             and
             give
             scope
             for
             the
             Rammers
             motions
             ,
             )
             and
             the
             Pump
             being
             set
             on
             worke
             ,
             we
             did
             ,
             after
             some
             quantity
             of
             Air
             was
             drawn
             out
             ,
             raise
             the
             Sucker
             a
             litle
             by
             the
             help
             of
             the
             Turning-key
             ,
             and
             then
             turning
             the
             same
             Key
             the
             contrary
             way
             we
             suffer'd
             the
             Weight
             to
             depress
             the
             Sucker
             ,
             that
             we
             might
             see
             at
             what
             rate
             the
             Feather
             would
             be
             blown
             up
             ;
             and
             finding
             that
             it
             was
             impell'd
             forceably
             enough
             ,
             we
             caus'd
             the
             pumping
             to
             be
             so
             continued
             ,
             that
             a
             pretty
             many
             pauses
             were
             made
             ,
             during
             each
             of
             which
             we
             rais'd
             and
             depress'd
             the
             Sucker
             as
             before
             ,
             and
             had
             the
             opportunity
             to
             observe
             ,
             That
             as
             the
             Receiver
             was
             more
             and
             more
             exhausted
             of
             the
             Air
             ,
             so
             the
             Feather
             was
             less
             and
             less
             briskly
             driven
             up
             ,
             till
             at
             length
             ,
             when
             the
             Receiver
             was
             well
             emptied
             ,
             the
             usual
             elevations
             and
             depressions
             of
             the
             Sucker
             would
             not
             blow
             it
             up
             at
             all
             that
             I
             could
             perceive
             ,
             though
             they
             were
             far
             more
             frequently
             repeated
             than
             ever
             before
             ;
             nor
             was
             I
             content
             to
             look
             heedfully
             my self
             ,
             but
             I
             made
             one
             whom
             I
             had
             
             often
             imploy'd
             about
             Pneumatical
             Experiments
             to
             watch
             attentively
             ,
             whilst
             I
             drew
             up
             ,
             and
             let
             down
             the
             Sucker
             ,
             but
             he
             affirm'd
             that
             he
             could
             not
             discern
             the
             least
             beginning
             of
             Ascension
             in
             the
             Feather
             .
             And
             indeed
             to
             both
             of
             us
             it
             seem'd
             ,
             that
             the
             litle
             and
             inconsiderable
             motion
             that
             was
             sometimes
             (
             not
             alwayes
             )
             to
             be
             discern'd
             in
             the
             Feather
             ,
             proceeded
             not
             from
             any
             thing
             that
             issued
             out
             of
             the
             Pipe
             ,
             but
             from
             some
             litle
             Shake
             ,
             which
             t
             was
             difficult
             not
             to
             give
             the
             Syringe
             and
             Pedestal
             ,
             by
             the
             raising
             and
             depressing
             of
             the
             Sucker
             .
          
           
             And
             that
             which
             made
             our
             Phaenomenon
             the
             more
             considerable
             ,
             was
             ,
             that
             the
             Weight
             that
             carried
             down
             the
             Sucker
             being
             still
             the
             same
             ,
             and
             the
             motions
             of
             the
             Turning-key
             being
             easie
             to
             be
             made
             equal
             at
             several
             times
             ,
             there
             seem'd
             no
             reason
             to
             suspect
             that
             Contingencies
             did
             much
             (
             if
             at
             all
             )
             favour
             the
             success
             ;
             but
             there
             hapned
             a
             thing
             ,
             which
             did
             manifestly
             enough
             disfavour
             it
             .
             For
             I
             remember
             ,
             that
             before
             the
             Syringe
             was
             put
             into
             the
             Receiver
             ,
             when
             we
             were
             trying
             how
             the
             Weight
             would
             depress
             it
             ,
             and
             it
             was
             thought
             that
             though
             the
             Weight
             were
             conveniently
             shap'd
             ,
             yet
             it
             was
             a
             litle
             of
             the
             least
             ;
             I
             would
             not
             alter
             it
             ,
             but
             foretold
             ,
             that
             when
             the
             Air
             in
             the
             Cavity
             of
             the
             Syringe
             (
             that
             now
             resisted
             the
             quickness
             of
             its
             descent
             ,
             because
             so
             much
             Air
             could
             not
             easily
             and
             nimbly
             get
             out
             at
             so
             small
             a
             Pipe
             )
             should
             be
             exhausted
             with
             the
             other
             Air
             of
             the
             Receiver
             ,
             the
             elevated
             Sucker
             would
             fall
             down
             more
             easily
             ,
             which
             he
             ,
             that
             was
             imploy'd
             to
             manage
             the
             Syringe
             whilst
             I
             watch'd
             the
             Feather
             ,
             affirm'd
             himself
             afterwards
             to
             observe
             very
             evidently
             .
             So
             that
             when
             the
             Receiver
             was
             exhausted
             ,
             if
             there
             had
             been
             in
             the
             cavity
             of
             the
             Syringe
             a
             matter
             as
             fit
             as
             Air
             to
             make
             a
             Wind
             of
             ,
             the
             Blast
             ought
             to
             have
             been
             Greater
             ,
             because
             the
             celerity
             that
             the
             Sucker
             was
             deprest
             with
             was
             so
             .
          
           
             After
             we
             had
             long
             enough
             tried
             in
             vain
             to
             raise
             the
             Feather
             ,
             I
             order'd
             some
             Air
             to
             be
             let
             into
             the
             Receiver
             ;
             and
             though
             when
             the
             admitted
             Air
             was
             but
             very
             litle
             ,
             the
             motions
             of
             the
             Sucker
             had
             scarce
             if
             at
             all
             any
             sensible
             operation
             upon
             the
             Feather
             ,
             yet
             when
             the
             quantity
             of
             Air
             began
             to
             be
             somewhat
             considerable
             ,
             
             the
             Feather
             began
             to
             be
             a
             litle
             mov'd
             upwards
             ,
             and
             so
             by
             letting
             in
             Air
             not
             all
             at
             once
             but
             more
             and
             more
             from
             time
             to
             time
             ,
             and
             by
             moving
             the
             Sucker
             up
             and
             down
             in
             the
             intervals
             of
             those
             times
             of
             admission
             ,
             we
             had
             the
             opportunity
             to
             observe
             ,
             that
             as
             the
             Receiver
             had
             more
             Air
             in
             it
             ,
             the
             Feather
             would
             be
             more
             briskly
             blown
             up
             .
          
           
             But
             not
             content
             with
             a
             single
             Tryal
             of
             an
             Experiment
             of
             this
             consequence
             ,
             we
             caused
             the
             Receiver
             to
             be
             again
             exhausted
             ,
             and
             prosecuted
             the
             Tryal
             with
             the
             like
             success
             as
             before
             ,
             onely
             this
             one
             Circumstance
             ,
             that
             we
             added
             for
             confirmation
             ,
             may
             be
             befit
             to
             be
             here
             taken
             notice
             of
             .
             Having
             ,
             after
             the
             Receiver
             was
             exhausted
             ,
             drawn
             up
             and
             let
             fall
             the
             Sucker
             divers
             times
             ineffectually
             ;
             though
             hitherto
             we
             had
             not
             usually
             rais'd
             it
             any
             higher
             at
             a
             time
             ,
             than
             we
             could
             by
             one
             turn
             of
             the
             hand
             ,
             both
             because
             we
             could
             not
             so
             conveniently
             raise
             it
             higher
             by
             the
             Hand
             alone
             ,
             and
             because
             we
             thought
             it
             unnecessary
             ,
             since
             that
             height
             suffic'd
             to
             make
             the
             Air
             briskly
             toss
             up
             the
             Feather
             ;
             yet
             
               ex
               abundanti
            
             we
             novv
             took
             an
             instrument
             that
             was
             pretty
             long
             and
             fit
             so
             to
             take
             hold
             on
             the
             Turning-key
             ,
             that
             we
             could
             easily
             raise
             the
             Sucker
             between
             two
             and
             three
             inches
             (
             by
             our
             Aestimate
             )
             at
             a
             time
             ,
             and
             nimbly
             depress
             it
             again
             ;
             and
             for
             all
             this
             ,
             which
             would
             much
             have
             increas'd
             the
             Blast
             ,
             if
             there
             had
             been
             a
             Matter
             fit
             for
             it
             in
             the
             Cavity
             of
             the
             Syringe
             ,
             we
             could
             not
             sensibly
             blow
             up
             the
             Feather
             ,
             till
             we
             had
             let
             a
             litle
             Air
             into
             the
             Receiver
             .
          
           
             To
             be
             able
             to
             make
             an
             aestimate
             of
             the
             Quantity
             of
             Air
             pump'd
             out
             ,
             or
             let
             in
             ,
             when
             the
             Feather
             vvas
             strongly
             or
             faintly
             ,
             or
             not
             at
             all
             rais'd
             by
             the
             fall
             of
             the
             Sucker
             ;
             vve
             took
             off
             the
             Receiver
             ,
             and
             convey'd
             a
             Gage
             into
             it
             ,
             but
             though
             for
             a
             vvhile
             vve
             made
             some
             use
             of
             our
             Gage
             ,
             yet
             a
             mischance
             befalling
             it
             before
             the
             Operation
             was
             quite
             ended
             ,
             I
             shall
             forbear
             to
             adde
             any
             thing
             concerning
             that
             Tryal
             ,
             and
             proceed
             to
             say
             something
             of
             another
             Attempt
             ,
             wherein
             though
             I
             foresaw
             and
             met
             with
             such
             difficulties
             ,
             as
             kept
             me
             from
             doing
             altogether
             what
             I
             desired
             ,
             yet
             the
             success
             being
             almost
             as
             good
             as
             could
             be
             expected
             ,
             I
             shall
             venture
             
             to
             acquaint
             Your
             Lordship
             with
             the
             Tryal
             ,
             which
             was
             this
             .
          
           
             In
             stead
             of
             the
             hitherto
             imploy'd
             Pipe
             of
             Brass
             ,
             there
             was
             well
             fastned
             (
             with
             Cement
             )
             to
             the
             Syringe
             a
             Pipe
             of
             Glass
             ,
             whose
             figure
             differ'd
             from
             that
             of
             the
             other
             in
             this
             particular
             ,
             that
             the
             shorter
             (
             or
             remoter
             )
             Leg
             of
             our
             new
             Pipe
             ,
             after
             it
             had
             for
             a
             while
             been
             carried
             parallel
             to
             the
             other
             Leg
             ,
             was
             bent
             off
             so
             ,
             that
             above
             an
             inch
             and
             a
             half
             of
             it
             tended
             downwards
             ,
             that
             the
             orifice
             of
             it
             might
             be
             immerst
             into
             Water
             contain'd
             in
             a
             small
             open
             Jarr
             .
             The
             design
             of
             which
             contrivance
             was
             ,
             that
             when
             the
             Receiver
             should
             be
             well
             exhausted
             ,
             we
             might
             (
             according
             to
             what
             I
             told
             Your
             Lordship
             vvas
             at
             first
             design'd
             )
             try
             vvhether
             by
             the
             raising
             and
             depressing
             of
             the
             Sucker
             any
             such
             Matter
             would
             be
             driven
             out
             at
             the
             nose
             of
             the
             Pipe
             ,
             as
             would
             produce
             bubbles
             in
             the
             incumbent
             Water
             ,
             which
             ,
             Air
             (
             though
             highly
             rarefied
             ,
             perhaps
             to
             some
             hundreds
             of
             times
             beyond
             its
             wonted
             Dimensions
             ,
             )
             is
             capable
             of
             doing
             .
             And
             I
             choose
             to
             imploy
             rather
             Water
             than
             Quick-silver
             ,
             because
             though
             by
             using
             the
             later
             I
             might
             hope
             to
             be
             less
             troubled
             with
             bubbles
             ,
             yet
             the
             ponderousness
             and
             opacity
             of
             it
             seem'd
             to
             outweigh
             that
             convenience
             .
          
           
             I
             need
             not
             tell
             Your
             Lordship
             ,
             that
             in
             other
             respects
             this
             Experiment
             was
             made
             like
             the
             former
             ,
             so
             that
             I
             shall
             mention
             onely
             its
             peculiarities
             ,
             which
             were
             ,
             That
             as
             the
             Air
             was
             pump'd
             out
             of
             the
             Receiver
             ,
             that
             in
             the
             Glass
             pipe
             made
             its
             way
             through
             the
             Water
             in
             Bubbles
             ,
             and
             a
             litle
             Air
             having
             once
             by
             a
             small
             Leak
             got
             in
             ,
             and
             forc'd
             some
             of
             the
             Water
             out
             of
             the
             Jarr
             into
             the
             pipe
             ,
             when
             the
             Receiver
             was
             again
             vvell
             emptied
             ,
             both
             that
             Water
             and
             even
             the
             litle
             quantity
             of
             stagnant
             Water
             ,
             that
             was
             contain'd
             in
             the
             immerst
             part
             of
             the
             Pipe
             ,
             produc'd
             so
             many
             bubbles
             of
             several
             sizes
             ,
             as
             quite
             disturb'd
             our
             Observations
             .
             Wherefore
             we
             let
             alone
             the
             Receiver
             ,
             exhausted
             as
             it
             was
             ,
             for
             6
             or
             7
             hours
             ,
             to
             give
             the
             Water
             time
             to
             be
             freed
             from
             Air
             ,
             and
             then
             causing
             what
             Air
             might
             have
             stolen
             in
             to
             be
             again
             pump'd
             out
             ,
             till
             we
             had
             perceiv'd
             by
             the
             Gage
             that
             the
             Receiver
             was
             well
             exhausted
             ,
             we
             caus'd
             the
             Sucker
             (
             of
             the
             Syringe
             )
             to
             be
             rais'd
             and
             deprest
             diverse
             
             times
             ,
             and
             though
             even
             then
             a
             Bubble
             vvould
             now
             and
             then
             make
             our
             Observations
             troublesome
             ,
             and
             less
             certain
             ,
             yet
             it
             seem'd
             to
             us
             ,
             that
             when
             we
             were
             not
             thus
             confounded
             ,
             we
             sometimes
             observed
             that
             the
             elevation
             and
             fall
             of
             the
             Sucker
             ,
             though
             reiterated
             ,
             did
             not
             drive
             out
             at
             the
             Pipe
             any
             thing
             that
             made
             any
             discernable
             bubbles
             in
             the
             incumbent
             Water
             ;
             for
             though
             there
             would
             appear
             now
             and
             then
             some
             small
             bubbles
             on
             the
             surface
             of
             the
             Water
             ,
             yet
             I
             could
             not
             perceive
             that
             the
             Matter
             that
             made
             them
             ,
             issued
             out
             at
             the
             Pipe
             ;
             and
             some
             of
             them
             manifestly
             proceeded
             from
             Aerial
             Particles
             ,
             till
             then
             lurking
             in
             the
             Water
             ,
             as
             I
             concluded
             from
             the
             place
             and
             time
             of
             their
             rising
             .
             But
             this
             Non-eruption
             of
             bubles
             at
             the
             nose
             of
             the
             Pipe
             ,
             vvas
             not
             that
             which
             gave
             me
             the
             most
             of
             satisfaction
             .
             For
             at
             length
             both
             I
             and
             another
             had
             the
             opportunity
             to
             observe
             the
             Water
             in
             the
             immerst
             part
             of
             the
             Pipe
             ,
             which
             was
             very
             slender
             ,
             to
             be
             about
             an
             inch
             higher
             than
             the
             rest
             of
             the
             stagnant
             Water
             ,
             and
             to
             continue
             at
             that
             height
             or
             place
             in
             the
             Pipe
             ,
             though
             the
             Sucker
             vvere
             divers
             times
             together
             rais'd
             and
             depress'd
             by
             Guess
             between
             2
             and
             three
             inches
             at
             a
             time
             .
             Which
             seem'd
             to
             argue
             ,
             either
             that
             there
             was
             a
             vacuum
             in
             the
             cavity
             of
             the
             Syringe
             ,
             or
             else
             that
             if
             it
             were
             full
             of
             Aether
             ,
             that
             body
             vvas
             so
             subtle
             ,
             that
             the
             impulse
             it
             received
             from
             the
             falling
             Sucker
             vvould
             not
             make
             it
             displeace
             a
             very
             litle
             Thread
             (
             perhaps
             not
             exceeding
             a
             Grain
             in
             Weight
             )
             of
             Water
             that
             vvas
             in
             the
             slender
             Pipe
             ,
             though
             it
             appear'd
             by
             the
             bubbles
             ,
             that
             sometimes
             disclos'd
             themselves
             in
             the
             Water
             ,
             after
             the
             Receiver
             had
             been
             exhausted
             ,
             that
             far
             more
             Water
             vvould
             be
             displac'd
             and
             carried
             up
             by
             a
             small
             bubble
             consisting
             of
             such
             rarified
             Air
             ,
             that
             according
             to
             my
             Aestimate
             the
             Aerial
             particles
             of
             it
             did
             not
             ,
             before
             the
             Pump
             vvas
             begun
             to
             be
             set
             on
             vvork
             ,
             take
             up
             in
             the
             Water
             a
             five-hundredth
             part
             of
             the
             quantity
             of
             a
             Pins
             head
             .
          
           
             But
             whilst
             we
             were
             considering
             what
             to
             do
             further
             in
             our
             Tryal
             ,
             a
             litle
             Air
             ,
             that
             strain'd
             in
             at
             some
             small
             undiscoverable
             Leak
             ,
             drove
             the
             Water
             into
             the
             emptied
             part
             of
             the
             Pipe
             ,
             and
             put
             an
             end
             for
             that
             time
             to
             our
             Tryal
             ,
             which
             had
             been
             too
             toylsome
             to
             invite
             us
             then
             to
             reiterate
             it
             .
          
           
           
             I
             had
             indeed
             thoughts
             of
             prosecuting
             the
             Enquiry
             ,
             by
             dropping
             from
             the
             top
             of
             the
             exhausted
             Receiver
             light
             Bodies
             conveniently
             shap'd
             ,
             to
             be
             turn'd
             round
             ,
             or
             otherwise
             put
             out
             of
             their
             simplest
             motion
             of
             Descent
             ,
             if
             they
             met
             with
             any
             resistance
             in
             their
             fall
             ;
             and
             by
             making
             such
             Bodies
             move
             Horizontally
             and
             otherwise
             in
             the
             Receiver
             ,
             as
             vvould
             probably
             discover
             whither
             they
             were
             assisted
             by
             the
             medium
             :
             and
             other
             contrivances
             and
             wayes
             I
             had
             in
             my
             thoughts
             ,
             whereby
             to
             prosecute
             our
             Enquiry
             ,
             but
             vvanting
             time
             for
             other
             Experiments
             ,
             I
             could
             not
             spare
             so
             much
             as
             was
             necessary
             to
             exhaust
             large
             Receivers
             so
             diligently
             ,
             as
             such
             nice
             Trials
             would
             exact
             ;
             and
             therefore
             I
             resolv'd
             to
             desist
             ,
             till
             I
             had
             more
             leisure
             than
             I
             then
             had
             ,
             (
             or
             have
             since
             been
             Master
             of
             .
             )
          
           
             In
             the
             interim
             ,
             thus
             much
             we
             seem
             to
             have
             already
             discovered
             by
             our
             past
             Tryals
             ,
             that
             if
             when
             our
             Vessels
             are
             very
             diligently
             freed
             from
             Air
             ,
             they
             are
             full
             of
             Aether
             ,
             that
             Aether
             is
             such
             a
             body
             ,
             as
             will
             not
             be
             made
             sensibly
             to
             move
             a
             light
             Feather
             by
             such
             an
             impulse
             as
             would
             make
             the
             Air
             manifestly
             move
             it
             ,
             not
             onely
             whilst
             t
             is
             no
             thinner
             than
             common
             Air
             ,
             but
             when
             t
             is
             very
             highly
             rarified
             ,
             (
             which
             ,
             if
             I
             mistake
             not
             ,
             it
             was
             in
             our
             Experiment
             so
             much
             ,
             as
             to
             be
             brought
             to
             take
             up
             above
             an
             hundred
             times
             more
             room
             than
             before
             .
             )
          
           
             And
             one
             thing
             more
             we
             gain'd
             by
             the
             Tryal
             made
             with
             water
             ,
             namely
             a
             clear
             confirmation
             of
             what
             I
             deliver'd
             in
             the
             34
             th
             Experiment
             ,
             about
             the
             cause
             of
             the
             Suction
             that
             is
             made
             by
             Syringes
             ;
             for
             Your
             Lordship
             may
             remember
             ,
             that
             at
             the
             close
             of
             the
             Experiment
             we
             have
             all
             this
             while
             been
             reciting
             ,
             I
             observ'd
             ,
             that
             when
             the
             external
             Air
             was
             so
             very
             well
             withdrawn
             ,
             the
             pulling
             up
             of
             the
             Sucker
             would
             not
             make
             the
             stagnant
             Water
             ,
             that
             the
             Pipe
             of
             the
             Syringe
             was
             immerst
             in
             ,
             to
             ascend
             one
             inch
             ,
             or
             so
             much
             as
             the
             tenth
             part
             of
             it
             .
          
        
         
           
           
             EXPERIMENT
             XL.
             
          
           
             About
             the
             falling
             ,
             in
             the
             Exhausted
             Receiver
             ,
             of
             a
             light
             Body
             ,
             fitted
             to
             have
             its
             motion
             visibly
             varied
             by
             a
             small
             resistance
             of
             the
             Air.
             
          
           
             PArtly
             to
             try
             whether
             in
             the
             space
             deserted
             by
             the
             Air
             ,
             drawn
             out
             of
             our
             Receivers
             ,
             there
             would
             be
             any
             thing
             more
             fit
             to
             resist
             the
             motion
             of
             other
             light
             Bodies
             through
             it
             ,
             than
             in
             the
             former
             Experiment
             we
             found
             It
             to
             impell
             them
             into
             motion
             ;
             and
             partly
             for
             another
             purpose
             to
             be
             mention'd
             by
             and
             by
             ,
             we
             made
             the
             following
             Tryals
             .
          
           
             We
             took
             a
             Receiver
             ,
             which
             ,
             though
             less
             tall
             than
             we
             would
             have
             had
             ,
             was
             the
             longest
             we
             could
             procure
             :
             and
             that
             we
             might
             be
             able
             ,
             not
             so
             properly
             to
             let
             down
             as
             ,
             to
             let
             fall
             a
             Body
             in
             it
             ,
             we
             so
             fastned
             a
             small
             pair
             of
             Tobacco-Tongs
             to
             the
             inside
             of
             the
             Receivers
             Brass-Cover
             ,
             that
             by
             moving
             the
             Turning-key
             ,
             we
             might
             by
             a
             string
             tied
             to
             one
             part
             of
             them
             ,
             open
             the
             Tongs
             ,
             which
             else
             their
             own
             Spring
             would
             keep
             shut
             .
             This
             being
             done
             ,
             the
             next
             thing
             was
             to
             provide
             a
             Body
             ,
             which
             vvould
             not
             fall
             down
             like
             a
             Stone
             ,
             or
             another
             dead
             Weight
             through
             the
             Air
             ,
             but
             would
             in
             the
             manner
             of
             its
             descent
             shew
             ,
             that
             its
             motion
             was
             somewhat
             resisted
             by
             the
             Air
             ;
             vvherefore
             that
             vve
             might
             have
             a
             Body
             that
             vvould
             be
             turn'd
             about
             Horizontally
             (
             as
             it
             were
             )
             in
             its
             fall
             ,
             we
             thought
             fit
             to
             joyn
             Cross-wise
             four
             broad
             and
             light
             Feathers
             (
             each
             about
             an
             Inch
             long
             )
             at
             their
             Quils
             with
             a
             litle
             Cement
             ,
             into
             vvhich
             vve
             also
             stuck
             perpendicularly
             a
             small
             Label
             of
             Paper
             ,
             about
             an
             8
             th
             of
             an
             inch
             in
             breadth
             ,
             and
             somewhat
             more
             in
             height
             ,
             by
             vvhich
             the
             Tongues
             might
             take
             hold
             of
             our
             light
             Instrument
             vvithout
             touching
             the
             Cement
             ,
             which
             else
             might
             stick
             to
             them
             .
          
           
             By
             the
             help
             of
             this
             small
             piece
             of
             Paper
             ,
             
             the
             litle
             Instrument
             ,
             of
             vvhich
             it
             made
             a
             part
             ,
             vvas
             so
             taken
             hold
             of
             by
             the
             Tongs
             ,
             that
             it
             hung
             as
             Horizontal
             as
             such
             a
             thing
             could
             well
             be
             plac'd
             :
             
             and
             then
             the
             Receiver
             being
             cemented
             on
             to
             the
             Engine
             ,
             the
             Pump
             vvas
             diligently
             ply'd
             ,
             till
             it
             appear'd
             by
             a
             Gage
             ,
             which
             had
             been
             conveyed
             in
             ,
             that
             the
             Reciver
             had
             been
             carefully
             exhausted
             :
             Lastly
             ,
             our
             eyes
             being
             attentively
             fix'd
             upon
             the
             connected
             Feathers
             ,
             the
             Tongs
             were
             by
             the
             help
             of
             the
             Turning-key
             open'd
             ,
             and
             the
             litle
             Instrument
             let
             fall
             ,
             which
             ,
             though
             in
             the
             Air
             it
             had
             made
             some
             turns
             in
             its
             descent
             from
             the
             same
             height
             it
             now
             fell
             from
             ,
             yet
             now
             it
             descended
             like
             a
             dead
             Weight
             ,
             without
             being
             perceiv'd
             by
             any
             of
             us
             to
             make
             so
             much
             as
             one
             Turn
             ,
             or
             a
             part
             of
             it
             :
             notwithstanding
             which
             I
             did
             ,
             for
             greater
             security
             ,
             cause
             the
             Receiver
             to
             be
             taken
             off
             ,
             and
             put
             on
             again
             ,
             after
             the
             Feathers
             were
             taken
             hold
             of
             by
             the
             Tongs
             ,
             whence
             being
             let
             fall
             in
             the
             Receiver
             unexhausted
             ,
             they
             made
             some
             Turns
             in
             their
             descent
             ,
             as
             they
             also
             did
             being
             a
             second
             time
             let
             fall
             after
             the
             same
             manner
             .
          
           
             But
             when
             after
             this
             ,
             the
             Feathers
             being
             plac'd
             as
             before
             ,
             we
             repeated
             the
             Experiment
             by
             carefully
             pumping
             out
             the
             Air
             ,
             neither
             I
             nor
             any
             of
             the
             By-standers
             could
             perceive
             any
             thing
             of
             Turning
             in
             the
             descent
             of
             the
             Feathers
             ;
             and
             yet
             for
             further
             security
             we
             let
             them
             fall
             twice
             more
             in
             the
             unexhausted
             Receiver
             ,
             and
             found
             them
             to
             turn
             in
             falling
             as
             before
             ;
             whereas
             when
             we
             did
             a
             3
             d
             time
             let
             them
             fall
             in
             the
             well
             exhausted
             Receiver
             ,
             they
             fell
             after
             the
             same
             manner
             as
             they
             had
             done
             formerly
             ,
             when
             the
             Air
             ,
             that
             vvould
             by
             its
             resistance
             have
             turn'd
             them
             round
             ,
             vvas
             remov'd
             out
             of
             their
             vvay
             .
          
           
             Note
             1.
             though
             (
             as
             I
             intimated
             above
             )
             the
             Glass
             ,
             vvherein
             this
             Experiment
             was
             made
             ,
             were
             nothing
             near
             so
             tall
             as
             I
             would
             have
             had
             it
             ,
             yet
             it
             was
             taller
             than
             any
             of
             our
             ordinary
             Receivers
             ,
             it
             being
             in
             height
             about
             22
             inches
             .
          
           
             2.
             
             One
             that
             had
             had
             more
             leisure
             and
             conveniency
             ,
             might
             have
             made
             a
             more
             commodious
             Instrument
             than
             that
             we
             made
             use
             of
             :
             for
             being
             accidentally
             visited
             by
             that
             Sagacious
             Mathematician
             D
             r
             Wren
             ,
             and
             speaking
             to
             him
             of
             this
             matter
             ,
             he
             was
             pleas'd
             with
             great
             dexterity
             as
             well
             as
             readiness
             to
             make
             me
             a
             little
             Instrument
             of
             Paper
             ,
             on
             which
             ,
             when
             t
             was
             let
             fall
             ,
             the
             resistance
             
             of
             the
             Air
             had
             so
             manifest
             an
             operation
             ,
             that
             I
             should
             have
             made
             use
             of
             it
             in
             our
             Experiment
             ,
             had
             it
             not
             been
             casually
             lost
             when
             the
             ingenious
             Maker
             was
             gone
             out
             of
             these
             parts
             .
          
           
             3.
             
             Though
             I
             have
             but
             briefly
             related
             our
             having
             so
             order'd
             the
             matter
             ,
             that
             we
             could
             conveniently
             let
             fall
             a
             Body
             in
             the
             Receiver
             when
             very
             well
             exhausted
             ,
             yet
             to
             contrive
             and
             put
             in
             practice
             what
             was
             necessary
             to
             perform
             this
             ,
             was
             not
             so
             very
             easie
             ,
             and
             it
             would
             be
             difficult
             to
             describe
             it
             circumstantially
             without
             very
             many
             words
             ;
             for
             which
             reason
             I
             forbear
             an
             account
             ,
             that
             would
             prove
             too
             tedious
             to
             us
             both
             .
          
           
             4.
             
             What
             has
             been
             hitherto
             related
             ,
             was
             done
             in
             prosecution
             of
             but
             one
             of
             the
             two
             Designs
             I
             aim'd
             at
             in
             the
             foregoing
             Contrivance
             ,
             by
             which
             I
             intended
             ,
             if
             I
             could
             have
             procured
             a
             Receiver
             tall
             enough
             ,
             to
             try
             whether
             Bodies
             (
             some
             very
             light
             ,
             and
             some
             heavier
             )
             being
             let
             fall
             when
             the
             Air
             was
             very
             diligently
             pump'd
             out
             ,
             would
             not
             descend
             somewhat
             faster
             than
             if
             the
             Receiver
             were
             full
             of
             Air.
             But
             though
             I
             had
             provided
             a
             Pendulum
             that
             vibrated
             quarters
             of
             Seconds
             ,
             yet
             the
             Glass
             being
             no
             higher
             than
             it
             was
             ,
             the
             Descent
             even
             of
             our
             Feathers
             took
             up
             so
             litle
             time
             ,
             that
             even
             this
             Pendulum
             was
             of
             no
             use
             ;
             onely
             it
             seem'd
             to
             all
             of
             us
             that
             were
             present
             at
             making
             the
             above
             recited
             Tryals
             ,
             that
             when
             the
             Feathers
             were
             let
             fall
             at
             such
             times
             as
             the
             Air
             (
             that
             would
             have
             turn'd
             them
             round
             in
             their
             descent
             )
             was
             removed
             ,
             they
             came
             to
             the
             bottom
             sensibly
             sooner
             than
             at
             other
             times
             .
             But
             when
             we
             shall
             have
             opportunity
             to
             repeat
             the
             Experiment
             in
             taller
             Glasses
             ,
             and
             to
             make
             some
             variation
             of
             it
             ,
             I
             hope
             to
             be
             able
             to
             give
             Your
             Lordship
             a
             fuller
             satisfaction
             about
             this
             Particular
             .
             And
             in
             the
             mean
             while
             I
             shall
             forbear
             to
             examine
             whether
             the
             Air
             might
             somewhat
             retard
             the
             descent
             of
             the
             Feathers
             upon
             some
             other
             account
             ,
             or
             meerly
             upon
             that
             of
             its
             being
             a
             medium
             not
             quite
             devoid
             of
             Gravity
             .
          
           
             
               Annotations
               .
            
             
               1.
               
               But
               here
               I
               must
               be
               so
               sincere
               as
               to
               inform
               Your
               Lordship
               ,
               that
               this
               40
               th
               Experiment
               seem'd
               not
               to
               prove
               so
               much
               as
               did
               the
               
               foregoing
               made
               with
               the
               Syringe
               :
               for
               being
               suspicious
               that
               ,
               to
               make
               the
               feathered
               body
               above
               mentioned
               turn
               in
               its
               fall
               ,
               there
               would
               need
               a
               resistance
               not
               altogether
               inconsiderable
               ,
               I
               caus'd
               the
               Experiment
               to
               be
               repeated
               ,
               when
               the
               Receiver
               was
               by
               our
               Aestimate
               (
               which
               was
               not
               made
               at
               random
               neither
               )
               litle
               or
               nothing
               more
               than
               half
               exhausted
               ,
               and
               yet
               the
               remaining
               Air
               was
               too
               far
               rarified
               to
               make
               the
               falling
               Body
               manifestly
               turn
               .
            
             
               2.
               
               And
               yet
               perchance
               it
               would
               have
               hapned
               otherwise
               ,
               if
               the
               Receiver
               had
               been
               tall
               enough
               ;
               which
               though
               I
               had
               not
               then
               leasure
               and
               conveniency
               to
               make
               it
               ,
               yet
               it
               will
               not
               be
               amiss
               to
               let
               Your
               Lorship
               know
               by
               what
               means
               we
               did
               ,
               that
               it
               might
               be
               somewhat
               fit
               to
               make
               the
               recited
               Experiment
               and
               some
               others
               ,
               bring
               it
               to
               the
               height
               it
               had
               ,
               which
               did
               considerably
               exceed
               that
               of
               the
               tallest
               Glass
               we
               could
               then
               procure
               .
            
             
               To
               lengthen
               our
               Receiver
               therefore
               ,
               we
               thought
               fit
               to
               try
               ,
               whether
               we
               could
               not
               close
               enough
               fasten
               to
               the
               bottom
               of
               it
               ,
               with
               very
               good
               Cement
               a
               Cylindrical
               Pipe
               of
               Laton
               ,
               whose
               upper
               orifice
               should
               have
               neer
               the
               same
               breadth
               with
               the
               bottom
               of
               the
               Glass
               .
               And
               though
               this
               Contrivance
               seem'd
               liable
               to
               a
               couple
               of
               not
               mean
               difficulties
               ;
               The
               one
               ,
               that
               the
               Laton
               being
               every
               where
               bended
               ,
               and
               in
               some
               places
               necessary
               to
               be
               souder'd
               ,
               it
               would
               be
               very
               hard
               (
               as
               indeed
               we
               found
               it
               )
               to
               avoid
               some
               small
               cracks
               and
               leaks
               :
               And
               the
               other
               ,
               that
               if
               the
               metalline
               Pipe
               were
               wide
               enough
               ,
               so
               great
               and
               heavy
               a
               pillar
               of
               the
               Atmosphere
               would
               come
               to
               bear
               against
               it
               ,
               as
               to
               press
               it
               inwards
               ,
               if
               not
               also
               to
               break
               it
               ;
               yet
               we
               hoped
               we
               should
               be
               able
               to
               obviate
               both
               of
               these
               inconveniences
               .
               Against
               the
               first
               of
               which
               our
               Remedy
               was
               ,
               to
               Coat
               over
               very
               carefully
               the
               whole
               Pipe
               with
               the
               same
               close
               Cement
               ,
               wherewith
               we
               fastned
               it
               to
               the
               Glass
               Receiver
               .
               And
               against
               the
               Second
               ,
               we
               provided
               a
               litle
               Frame
               consisting
               of
               divers
               small
               Iron
               Bars
               fastned
               together
               ;
               which
               Frame
               (
               though
               t
               were
               not
               too
               wide
               to
               go
               into
               the
               Cylinder
               of
               Laton
               ,
               yet
               it
               )
               was
               wide
               enough
               to
               be
               so
               neer
               it
               on
               the
               inside
               ,
               that
               (
               though
               the
               weight
               of
               the
               Atmosphere
               should
               ,
               as
               we
               feared
               ,
               press
               the
               Laton
               so
               as
               to
               make
               
               it
               yield
               inward
               ,
               yet
               )
               it
               could
               make
               it
               bend
               no
               further
               than
               the
               Iron-frame
               would
               permit
               ;
               which
               was
               not
               far
               enough
               to
               spoile
               either
               the
               Receiver
               or
               the
               Experiment
               .
               And
               this
               not
               unpleasant
               phaenomenon
               would
               somewhat
               surprise
               unaccustomed
               Spectators
               ,
               that
               when
               after
               the
               Receiver
               had
               been
               very
               well
               exhausted
               ,
               the
               external
               Air
               was
               permitted
               to
               return
               ,
               there
               would
               be
               heard
               during
               some
               time
               ,
               from
               the
               metalline
               part
               of
               the
               Receiver
               ,
               divers
               Sounds
               brisk
               enough
               ,
               which
               would
               make
               an
               odd
               Cracking
               noise
               proceeding
               from
               the
               Laton-plate
               ,
               which
               having
               been
               forceably
               ,
               though
               but
               slowly
               ,
               bent
               inwards
               by
               the
               predominant
               Pressure
               of
               the
               Atmosphere
               ,
               was
               now
               assisted
               by
               the
               Pressure
               of
               the
               returning
               Air
               ,
               to
               regain
               its
               former
               Figure
               .
               And
               as
               I
               thought
               not
               fit
               to
               omit
               this
               Circumstance
               ,
               because
               it
               confirms
               the
               practicableness
               of
               the
               Remedy
               propos'd
               against
               the
               2
               d
               Inconvenience
               ;
               so
               I
               thought
               fit
               to
               mention
               this
               way
               of
               enlarging
               and
               heightning
               Receivers
               ,
               because
               what
               we
               have
               related
               seems
               to
               give
               Grounds
               of
               hoping
               that
               this
               Contrivance
               may
               be
               made
               good
               use
               of
               in
               divers
               other
               Tryals
               ,
               and
               particularly
               in
               attempts
               to
               make
               Receivers
               capacious
               enough
               to
               contain
               larger
               Animals
               ,
               and
               perhaps
               even
               a
               Boy
               ,
               or
               a
               Man.
               In
               order
               to
               some
               of
               which
               purposes
               we
               indeavoured
               to
               get
               an
               improvement
               made
               of
               our
               Metalline
               Cylinder
               by
               additional
               contrivances
               ;
               but
               could
               not
               (
               where
               we
               then
               were
               )
               get
               Artificers
               ,
               that
               would
               perform
               what
               was
               directed
               .
            
          
        
         
           
             EXPERIMENT
             XLI
             .
          
           
             About
             the
             propagation
             of
             Sounds
             in
             the
             Exhausted
             Receiver
             .
          
           
             TO
             make
             some
             further
             Observation
             than
             is
             mention'd
             in
             the
             *
             Publish'd
             Experiments
             ,
             about
             the
             Production
             and
             conveying
             of
             Sounds
             in
             a
             Glass
             whence
             the
             Air
             is
             drawn
             out
             ,
             we
             imploy'd
             a
             Contrivance
             ,
             of
             which
             (
             because
             we
             make
             use
             of
             it
             in
             divers
             
             other
             Experiments
             )
             it
             will
             be
             requisite
             to
             give
             Your
             Lordship
             here
             some
             short
             description
             .
          
           
             We
             caus'd
             to
             be
             made
             at
             the
             Turners
             a
             Cylinder
             of
             Box
             ,
             or
             the
             like
             close
             and
             firme
             Wood
             ,
             and
             of
             a
             length
             suitable
             to
             that
             of
             the
             Receiver
             it
             was
             to
             be
             imploy'd
             in
             .
             Out
             of
             the
             lower
             Basis
             of
             this
             Cylinder
             (
             vvhich
             might
             be
             about
             an
             inch
             and
             a
             half
             in
             Diameter
             )
             there
             came
             a
             smaller
             Cylinder
             or
             Axle-tree
             not
             a
             quarter
             so
             thick
             as
             the
             other
             ,
             
             and
             less
             than
             an
             inch
             long
             :
             this
             vvas
             Turn'd
             very
             true
             ,
             that
             it
             might
             move
             to
             &
             fro
             (
             or
             ,
             as
             the
             Tradesmen
             call
             it
             ,
             Ride
             )
             very
             smoothly
             in
             a
             litle
             Ferrule
             or
             Ring
             of
             Brass
             ,
             that
             was
             by
             the
             same
             Turner
             made
             for
             it
             in
             the
             midst
             of
             the
             fixt
             Trencher
             ,
             (
             as
             we
             call
             a
             piece
             of
             solid
             Wood
             shap'd
             like
             a
             Milstone
             ,
             )
             being
             4
             or
             5
             inches
             (
             more
             or
             less
             according
             to
             the
             wideness
             of
             the
             Receiver
             )
             in
             breadth
             ,
             and
             between
             one
             and
             two
             in
             thickness
             ;
             and
             in
             a
             large
             and
             round
             Groove
             ,
             or
             Gutter
             ,
             purposely
             made
             in
             the
             lower
             part
             of
             this
             Trencher
             ,
             I
             caus'd
             as
             much
             Lead
             as
             vvould
             fill
             it
             up
             to
             be
             plac'd
             and
             fasten'd
             ,
             that
             it
             might
             keep
             the
             Trencher
             from
             being
             easily
             mov'd
             out
             of
             its
             place
             or
             posture
             ,
             and
             in
             the
             upper
             part
             of
             this
             Trencher
             it
             vvas
             intended
             that
             Holes
             should
             be
             made
             at
             such
             places
             as
             should
             be
             thought
             fit
             ,
             to
             place
             bodies
             at
             several
             distances
             as
             occasion
             should
             require
             .
             The
             upper
             Basis
             of
             the
             Cylinder
             had
             also
             coming
             out
             of
             the
             midst
             of
             it
             another
             Axletree
             ,
             but
             wider
             than
             the
             former
             ,
             that
             ,
             into
             a
             Cavity
             made
             in
             it
             ,
             it
             might
             receive
             the
             lower
             end
             of
             the
             Turning-key
             divers
             times
             already
             mentioned
             ,
             to
             which
             t
             was
             to
             be
             fastned
             by
             a
             slender
             peg
             of
             Brass
             ,
             thrust
             through
             two
             correspondent
             holes
             ,
             the
             one
             made
             in
             the
             Key
             ,
             and
             the
             other
             in
             the
             newly
             mentioned
             Socket
             (
             if
             I
             may
             so
             call
             it
             )
             of
             the
             Axletree
             .
             Besides
             all
             vvhich
             ,
             there
             were
             divers
             Horizontal
             Perforations
             bored
             here
             and
             there
             in
             the
             Pillar
             it self
             ,
             to
             which
             this
             Axis
             belong'd
             ,
             vvhich
             Pillar
             we
             shall
             to
             avoid
             ambiguity
             call
             the
             Vertical
             Cylinder
             .
             The
             general
             use
             of
             this
             contrivance
             (
             whose
             other
             parts
             need
             not
             to
             be
             mentioned
             before
             the
             Experiments
             where
             they
             are
             imploy'd
             )
             is
             ,
             that
             the
             end
             of
             the
             Turning-key
             being
             put
             into
             the
             Socket
             ,
             and
             the
             lower
             Axis
             of
             
             the
             Vertical
             Cylinder
             into
             the
             Trencher
             ,
             by
             the
             motion
             of
             the
             Key
             a
             Body
             fasten'd
             at
             one
             of
             the
             holes
             to
             the
             Cylinder
             may
             be
             approach'd
             too
             ,
             or
             remov'd
             from
             ,
             or
             made
             to
             rub
             or
             strike
             against
             another
             Body
             fastned
             in
             a
             convenient
             posture
             to
             the
             upper
             part
             of
             the
             Trencher
             .
          
           
             To
             come
             now
             to
             our
             Tryal
             about
             Sounds
             ,
             vve
             caus'd
             a
             Hand-Bell
             (
             vvhose
             Handle
             and
             Clapper
             were
             taken
             away
             )
             to
             be
             so
             fastned
             to
             a
             strng
             Wire
             ,
             that
             ,
             one
             end
             of
             the
             Wire
             being
             made
             fast
             in
             the
             Trencher
             ,
             the
             other
             end
             ,
             vvhich
             vvas
             purposely
             bent
             downwards
             ,
             took
             hold
             of
             the
             Bell.
             In
             another
             hole
             ,
             made
             in
             the
             circumference
             of
             the
             same
             Trencher
             ,
             vvas
             vvedg'd
             in
             (
             vvith
             a
             wooden
             Peg
             )
             a
             Steel-spring
             ,
             to
             whose
             upper
             part
             was
             tied
             a
             Gad
             of
             Iron
             or
             Steel
             ,
             less
             than
             an
             inch
             long
             ,
             but
             of
             a
             pretty
             thickness
             .
             The
             length
             of
             this
             Spring
             was
             such
             ,
             as
             to
             make
             the
             upper
             part
             of
             the
             Hammer
             (
             if
             I
             may
             so
             call
             the
             piece
             of
             Iron
             )
             of
             the
             same
             height
             with
             the
             Bell
             ,
             
             and
             the
             distance
             of
             the
             Spring
             from
             the
             Bell
             was
             such
             ,
             that
             when
             it
             was
             forc'd
             back
             the
             other
             way
             ,
             it
             might
             at
             its
             return
             make
             the
             Hammer
             strike
             briskly
             upon
             the
             outside
             of
             the
             Bell.
             
          
           
             The
             Trencher
             being
             thus
             furnisht
             and
             plac'd
             in
             a
             Capp'd
             Receiver
             ,
             (
             as
             You
             know
             ,
             for
             brevity
             sake
             ,
             we
             use
             to
             call
             one
             that
             is
             fitted
             with
             one
             or
             other
             of
             the
             Brass
             Covers
             ,
             often
             mentioned
             already
             ,
             )
             the
             Air
             was
             diligently
             pump'd
             out
             ;
             and
             then
             ,
             by
             the
             help
             of
             the
             Turning-key
             ,
             the
             Vertical
             Cylinder
             was
             made
             to
             go
             round
             ,
             by
             which
             means
             as
             often
             as
             either
             of
             a
             couple
             of
             stiff
             Wires
             ,
             or
             small
             Pegs
             ,
             that
             were
             fastned
             at
             right
             Angles
             into
             holes
             ,
             made
             not
             far
             from
             the
             bottom
             of
             the
             Cylinder
             ,
             pass'd
             (
             under
             the
             Bell
             ,
             and
             )
             by
             the
             lately
             mentioned
             Spring
             ;
             they
             forceably
             did
             in
             their
             passage
             bend
             it
             from
             the
             Bell
             ,
             by
             which
             means
             ,
             as
             soon
             as
             the
             Wire
             was
             gone
             by
             ,
             and
             the
             Spring
             ceas'd
             to
             be
             press'd
             ,
             it
             would
             fly
             back
             with
             violence
             ,
             enough
             to
             make
             the
             Hammer
             give
             a
             smart
             stroak
             upon
             the
             Bell.
             And
             by
             this
             means
             we
             could
             both
             continue
             the
             Experiment
             at
             discretion
             ,
             and
             make
             the
             percussions
             more
             equally
             strong
             than
             it
             would
             otherwise
             have
             been
             easie
             to
             do
             .
          
           
           
             The
             event
             of
             our
             Tryal
             was
             ;
             That
             ,
             when
             the
             Receiver
             was
             vvell
             emptied
             ,
             it
             sometimes
             seem'd
             doubtful
             ,
             especially
             to
             some
             of
             the
             By-standers
             ,
             whether
             any
             Sound
             were
             produc'd
             or
             no
             ;
             but
             to
             me
             for
             the
             most
             part
             it
             seem'd
             ,
             that
             after
             much
             attention
             I
             heard
             a
             Sound
             ,
             that
             I
             could
             but
             just
             hear
             ;
             and
             yet
             ,
             vvhich
             is
             odd
             ,
             me
             thought
             it
             had
             somewhat
             of
             the
             nature
             of
             Shrilness
             in
             it
             ,
             but
             seem'd
             (
             which
             is
             not
             strange
             )
             to
             come
             from
             a
             good
             way
             off
             .
             Whether
             the
             often
             turning
             of
             the
             Cylindrical
             Key
             kept
             the
             Receiver
             from
             being
             so
             stanch
             as
             else
             it
             vvould
             have
             been
             ,
             upon
             vvhich
             score
             some
             litle
             Air
             might
             insinuate
             it self
             ,
             I
             shall
             not
             positively
             determine
             :
             but
             to
             discover
             vvhat
             interest
             the
             Presence
             or
             the
             absence
             of
             the
             Air
             might
             have
             in
             the
             Loudness
             or
             Lowness
             of
             the
             Sound
             ,
             I
             caus'd
             the
             Air
             to
             be
             let
             into
             the
             Receiver
             ,
             not
             all
             at
             once
             but
             at
             several
             times
             ,
             with
             competent
             intervals
             between
             them
             ;
             by
             which
             Expedient
             it
             was
             easie
             to
             observe
             ,
             that
             the
             Vertical
             Cylinder
             being
             still
             made
             to
             go
             round
             ,
             when
             a
             litle
             Air
             vvas
             let
             in
             ,
             the
             stroak
             of
             the
             Hammer
             upon
             the
             Bell
             (
             that
             before
             could
             now
             and
             then
             not
             be
             heard
             ,
             and
             for
             the
             most
             part
             be
             but
             very
             scarcely
             heard
             )
             began
             to
             be
             easily
             heard
             .
             And
             when
             a
             litle
             more
             Air
             was
             let
             in
             ,
             the
             Sound
             grew
             more
             and
             more
             audible
             ,
             and
             so
             increased
             ,
             till
             the
             Receiver
             was
             again
             replenished
             with
             Air
             ;
             though
             even
             then
             (
             that
             we
             omit
             not
             That
             phaenomenon
             )
             the
             Sound
             was
             observ'd
             to
             be
             much
             less
             loud
             than
             when
             the
             Receiver
             was
             not
             interpos'd
             between
             the
             Bell
             and
             the
             Ear.
             
          
           
             And
             whereas
             in
             the
             already
             publish'd
             Physico-Mechanical
             Experiments
             I
             acquainted
             Your
             Lordship
             with
             what
             I
             observ'd
             about
             the
             Sound
             of
             an
             ordinary
             Watch
             in
             the
             Exhausted
             Receiver
             ,
             I
             shall
             now
             adde
             ,
             that
             That
             Experiment
             was
             repeated
             not
             long
             since
             ,
             with
             the
             addition
             of
             suspending
             in
             the
             Receiver
             a
             Watch
             ,
             with
             a
             good
             Alarum
             ,
             which
             was
             purposely
             so
             set
             ,
             that
             it
             might
             ,
             before
             it
             should
             begin
             to
             ring
             ,
             give
             us
             time
             to
             cement
             on
             the
             Receiver
             very
             carefully
             ,
             exhaust
             it
             very
             diligently
             ,
             and
             settle
             our selves
             in
             a
             silent
             and
             attentive
             posture
             .
             And
             to
             make
             this
             Experiment
             in
             some
             respect
             more
             accurate
             than
             the
             others
             we
             
             made
             of
             Sounds
             ,
             we
             secur'd
             our selves
             against
             any
             leaking
             at
             the
             Top
             ,
             by
             imploying
             a
             Receiver
             that
             was
             made
             all
             of
             one
             piece
             of
             Glass
             ,
             (
             and
             consequently
             had
             no
             Cover
             cemented
             on
             to
             it
             ,
             )
             being
             furnish'd
             onely
             within
             (
             when
             't
             was
             first
             blown
             )
             with
             a
             Glass-knob
             or
             Button
             ,
             to
             which
             a
             string
             might
             be
             tied
             .
             And
             because
             it
             might
             be
             suspected
             ,
             that
             if
             the
             Watch
             were
             suspended
             by
             its
             own
             Silver
             Chain
             ,
             the
             tremulous
             motion
             of
             its
             sounding
             Bell
             might
             be
             propagated
             by
             that
             Metalline
             Chain
             to
             the
             upper
             part
             of
             the
             Glass
             ;
             to
             obviate
             this
             as
             well
             as
             we
             could
             ,
             we
             hung
             the
             Watch
             ,
             not
             by
             its
             Chain
             ,
             but
             a
             very
             slender
             Thread
             ,
             whose
             upper
             end
             was
             fastned
             to
             the
             newly
             mentioned
             Glass-button
             .
          
           
             These
             things
             being
             done
             ,
             and
             the
             Air
             being
             carefully
             pump'd
             out
             ,
             we
             silently
             expected
             the
             time
             when
             the
             Alarum
             should
             begin
             to
             ring
             ,
             which
             't
             was
             easie
             to
             know
             by
             the
             help
             of
             our
             other
             Watches
             ;
             but
             not
             hearing
             any
             noise
             so
             soon
             as
             we
             expected
             ,
             it
             would
             perhaps
             have
             been
             doubted
             whether
             the
             Watch
             continued
             Going
             ,
             if
             for
             prevention
             we
             had
             not
             order'd
             the
             matter
             so
             ,
             that
             we
             could
             discern
             it
             did
             not
             stand
             still
             .
             Wherefore
             I
             desir'd
             an
             ingenious
             Gentleman
             to
             hold
             his
             Ear
             just
             over
             the
             Button
             ,
             at
             which
             the
             Watch
             was
             suspended
             ,
             and
             to
             hold
             it
             also
             very
             near
             to
             the
             Receiver
             ,
             upon
             which
             he
             told
             us
             that
             he
             could
             perceive
             ,
             and
             but
             just
             perceive
             something
             of
             Sound
             ,
             that
             seem'd
             to
             come
             from
             far
             ;
             though
             neither
             we
             that
             listned
             very
             attentively
             near
             other
             parts
             of
             the
             Receiver
             ,
             nor
             he
             ,
             if
             his
             Ears
             were
             no
             more
             advantaged
             in
             point
             of
             position
             than
             Ours
             ,
             were
             satisfied
             that
             we
             heard
             the
             Watch
             at
             all
             .
             Wherefore
             ordering
             some
             Air
             to
             be
             let
             in
             ,
             we
             did
             by
             the
             help
             of
             attention
             begin
             to
             hear
             the
             Alarum
             ;
             whose
             Sound
             was
             odd
             enough
             ,
             and
             ,
             by
             returning
             the
             Stop-cock
             to
             keep
             any
             more
             Air
             from
             getting
             in
             ,
             we
             kept
             the
             Sound
             thus
             low
             for
             a
             pretty
             while
             ,
             after
             which
             a
             little
             more
             Air
             ,
             that
             was
             permitted
             to
             enter
             ,
             made
             it
             become
             more
             audible
             ;
             and
             when
             the
             Air
             was
             yet
             more
             freely
             admitted
             ,
             the
             by
             standers
             could
             plainly
             hear
             the
             noise
             of
             the
             yet
             continuing
             Alarum
             at
             a
             considerable
             distance
             from
             the
             Receiver
             .
          
           
           
             From
             what
             has
             hitherto
             been
             related
             we
             may
             learn
             what
             is
             to
             be
             thought
             of
             what
             is
             delivered
             by
             the
             Learned
             Mersennus
             ,
             in
             that
             Book
             of
             his
             Harmonicks
             ,
             where
             he
             makes
             this
             to
             be
             the
             first
             Proposition
             .
             
               Sonus
               à
               Campanis
               ,
               vel
               aliis
               corporibus
               non
               solùm
               producitur
               in
               illo
               vacuo
               (
               quicquid
               tandem
               illud
               sit
               ,
               )
               quod
               fit
               in
               Tubis
               Hydrargyro
               plenis
               ,
               posteaque
               depletis
               ,
               sed
               etiam
               idem
               acumen
               ,
               quod
               in
               Aere
               libero
               vel
               clauso
               penitus
               observatur
               &
               auditur
               .
            
             For
             the
             proof
             of
             which
             Assertion
             ,
             not
             long
             after
             ,
             he
             speaks
             thus
             :
             
               Porro
               variis
               Tubis
               ,
               quorum
               extremis
               lagenae
               vitreae
               adglutinantur
               ,
               observari
               Campanas
               in
               illo
               vacuo
               appensas
               ,
               propriisque
               malleis
               percussas
               idem
               penitus
               acumen
               retinere
               ,
               quod
               in
               Aere
               libero
               habent
               :
               atque
               soni
               magnitudinem
               ei
               sono
               ,
               qui
               fit
               in
               Aere
               quem
               Tubus
               clausus
               includit
               ,
               nihil
               cedere
               .
            
             But
             though
             our
             Experiments
             sufficiently
             manifest
             that
             the
             presence
             or
             absence
             of
             the
             common
             Air
             is
             of
             no
             small
             importance
             as
             to
             the
             conveying
             of
             Sounds
             ,
             and
             that
             the
             interposition
             of
             Glass
             may
             sensibly
             weaken
             them
             ;
             yet
             so
             diligent
             and
             faithful
             a
             Writer
             as
             Mersennus
             deserves
             to
             be
             favourably
             treated
             :
             and
             therefore
             I
             shall
             represent
             on
             his
             behalf
             ,
             that
             what
             he
             sayes
             may
             well
             enough
             have
             been
             true
             ,
             as
             far
             as
             could
             be
             gathered
             from
             the
             Tryals
             he
             made
             .
             For
             First
             ,
             t
             is
             no
             easie
             matter
             ,
             especially
             for
             those
             that
             have
             not
             peculiar
             and
             very
             close
             Cements
             ,
             to
             keep
             the
             Air
             quite
             out
             for
             any
             considerable
             time
             in
             vessels
             consisting
             of
             divers
             pieces
             ,
             such
             as
             he
             appears
             to
             have
             made
             use
             of
             .
             And
             next
             ,
             the
             bigness
             of
             the
             Bell
             in
             reference
             to
             the
             capacity
             of
             the
             exhausted
             Glass
             ,
             and
             the
             thickness
             of
             the
             Glass
             ,
             and
             the
             manner
             whereby
             the
             Bell
             was
             fastned
             to
             the
             inside
             of
             the
             Glass
             ,
             and
             the
             Hammer
             or
             Clapper
             was
             made
             to
             strike
             ,
             may
             much
             vary
             the
             Effect
             of
             the
             Tryal
             ,
             for
             Reasons
             easie
             to
             be
             gather'd
             out
             of
             the
             past
             Discourse
             ,
             and
             therefore
             not
             needful
             to
             be
             here
             insisted
             on
             .
             And
             upon
             this
             Account
             we
             chose
             to
             make
             our
             Experiment
             ,
             with
             sounds
             that
             should
             not
             be
             strong
             or
             loud
             ,
             and
             to
             produce
             them
             after
             such
             a
             manner
             ,
             as
             that
             as
             litle
             shaking
             as
             could
             be
             might
             be
             given
             by
             the
             sounding
             Body
             to
             the
             Glass
             't
             was
             included
             in
             .
             The
             Proposal
             made
             by
             the
             same
             Mersennus
             ,
             to
             have
             those
             that
             have
             industry
             enough
             ,
             
             try
             whether
             a
             Bag-pipe
             will
             be
             made
             to
             afford
             the
             same
             Sound
             as
             in
             the
             open
             Air
             ,
             in
             such
             Vessels
             as
             he
             used
             for
             his
             Bels
             ,
             though
             he
             seems
             to
             think
             it
             would
             succeed
             ,
             is
             that
             which
             Your
             Lordship
             will
             not
             ,
             I
             presume
             ,
             sollicite
             me
             to
             make
             Tryal
             of
             ,
             if
             You
             remember
             what
             is
             related
             in
             the
             almost
             immediately
             foregoing
             Experiments
             ,
             shewing
             ,
             That
             we
             could
             make
             nothing
             come
             out
             of
             the
             Cavity
             of
             a
             pair
             of
             Bellows
             ,
             that
             had
             force
             enough
             to
             blow
             away
             a
             Feather
             ,
             when
             that
             Cavity
             was
             freed
             from
             Air
             ;
             as
             the
             Bagpipe
             would
             be
             by
             the
             same
             operation
             ,
             that
             empties
             the
             Glass
             that
             contains
             it
             ,
             or
             else
             the
             Sound
             would
             not
             be
             made
             in
             such
             a
             Vacuum
             as
             the
             scope
             of
             the
             Experiment
             requires
             .
          
           
             If
             I
             had
             had
             Conveniency
             ,
             I
             would
             have
             made
             some
             Tryals
             by
             conveying
             a
             small
             string'd
             Instrument
             (
             perhaps
             some
             such
             as
             they
             commonly
             call
             a
             Kit
             )
             exactly
             tun'd
             ,
             into
             a
             large
             Receiver
             ,
             and
             then
             upon
             briskly
             striking
             the
             String
             of
             a
             bigger
             Instrument
             ,
             (
             tuned
             ,
             as
             they
             speak
             ,
             to
             an
             Unison
             to
             (
             or
             with
             )
             that
             of
             the
             smaller
             Instrument
             )
             I
             should
             have
             taken
             notice
             ,
             whether
             the
             Sound
             would
             have
             been
             so
             uniformly
             propagated
             ,
             notwithstanding
             the
             Interposition
             of
             the
             Glass
             Receiver
             ,
             as
             sensibly
             to
             shake
             the
             included
             String
             ;
             in
             order
             to
             the
             discerning
             of
             which
             ,
             a
             bended
             piece
             of
             Straw
             ,
             or
             Feather
             ,
             or
             some
             such
             light
             body
             ,
             was
             to
             be
             hors'd
             upon
             the
             String
             to
             be
             shaken
             .
             I
             also
             intended
             ,
             in
             case
             the
             string
             were
             made
             to
             move
             ,
             to
             make
             the
             like
             Tryal
             after
             the
             Receiver
             was
             diligently
             exhausted
             .
             And
             lastly
             I
             design'd
             to
             try
             ,
             whether
             two
             Unison
             strings
             of
             the
             same
             Instruments
             ,
             or
             of
             a
             couple
             to
             be
             plac'd
             in
             the
             same
             Receiver
             ,
             would
             ,
             when
             the
             Air
             (
             which
             is
             the
             usual
             medium
             of
             Sounds
             )
             was
             well
             pump'd
             out
             ,
             yet
             maintain
             such
             a
             Sympathy
             (
             as
             t
             is
             call'd
             ,
             )
             that
             upon
             the
             motion
             of
             the
             one
             ,
             the
             other
             would
             also
             be
             made
             to
             stir
             :
             Which
             Tryals
             may
             be
             varied
             ,
             by
             imploying
             for
             the
             external
             Instrument
             another
             in
             stead
             of
             a
             stringed
             one
             .
          
           
             And
             because
             Contraries
             (
             as
             is
             vulgarly
             noted
             )
             serve
             to
             illustrate
             each
             other
             ,
             I
             thought
             to
             subjoyn
             ,
             to
             the
             Tryals
             above
             related
             ,
             about
             the
             propagation
             of
             Sounds
             in
             a
             
               thinner
               medium
            
             than
             the
             
             Air
             ,
             some
             observations
             about
             the
             conveyance
             of
             them
             through
             that
             
               thicker
               medium
            
             ,
             Water
             ;
             but
             having
             unluckily
             mislaid
             my
             Notes
             upon
             that
             Subject
             ,
             I
             cannot
             at
             present
             acquaint
             Your
             Lordship
             with
             what
             I
             intended
             ,
             but
             must
             defer
             the
             doing
             it
             ,
             till
             I
             shall
             have
             recovered
             Them.
             
          
        
         
           
             EXPERIMENT
             XLII
             .
          
           
             About
             the
             breaking
             of
             a
             Glass-drop
             in
             an
             Exhausted
             Receiver
             .
          
           
             YOu
             know
             ,
             that
             among
             the
             Causes
             that
             have
             been
             propos'd
             of
             the
             strange
             flying
             of
             a
             Glass-drop
             into
             a
             multitude
             of
             pieces
             ,
             when
             the
             slender
             Stem
             of
             it
             comes
             to
             be
             broken
             off
             ,
             One
             of
             the
             least
             improbable
             was
             taken
             from
             the
             Pressure
             of
             the
             Air
             :
             as
             if
             that
             within
             the
             poreous
             (
             and
             as
             't
             were
             honey-comb'd
             )
             inside
             of
             the
             Glass
             ,
             being
             highly
             rarified
             when
             the
             drop
             of
             melted
             Glass
             fell
             into
             the
             Water
             at
             its
             first
             formation
             ,
             it
             was
             forc'd
             to
             continue
             in
             that
             praeternatural
             state
             of
             Expansion
             by
             the
             hardness
             and
             closeness
             of
             the
             external
             Case
             of
             Glass
             ,
             that
             inclos'd
             the
             Pithlike
             part
             (
             if
             I
             may
             so
             call
             it
             ;
             )
             so
             that
             upon
             the
             breaking
             off
             a
             part
             of
             this
             solid
             Case
             at
             the
             Stem
             ,
             the
             external
             Air
             gaining
             access
             ,
             and
             finding
             in
             the
             Spungy
             part
             very
             litle
             resistance
             from
             the
             highly
             rarified
             and
             conse
             quently
             weaken'd
             Air
             included
             there
             ,
             rushes
             in
             with
             such
             violence
             ,
             as
             to
             shiver
             the
             Glass-drop
             into
             a
             multitude
             of
             pieces
             .
          
           
             I
             shall
             not
             now
             trouble
             Your
             Lordship
             with
             the
             mention
             of
             what
             may
             be
             alleadg'd
             to
             question
             this
             Hypothesis
             ,
             especially
             if
             it
             be
             compared
             with
             that
             accurate
             Account
             of
             the
             Phaenomena
             of
             such
             Glass-drops
             ,
             which
             was
             sometime
             since
             presented
             to
             the
             Society
             by
             that
             great
             Ornament
             of
             it
             ,
             S
             r
             
               Robert
               Moray
            
             .
             But
             I
             shall
             onely
             say
             in
             this
             place
             ,
             that
             when
             I
             consider'd
             ,
             that
             if
             the
             Dissilition
             of
             the
             Glass
             would
             succeed
             when
             the
             Air
             was
             pump'd
             out
             of
             
             it
             ,
             it
             would
             be
             hard
             to
             ascribe
             that
             Effect
             to
             the
             irruption
             of
             the
             external
             Air
             ,
             I
             thought
             fit
             to
             try
             what
             would
             happen
             ,
             if
             a
             Glass-drop
             were
             broken
             in
             our
             exhausted
             Receiver
             .
             And
             accordingly
             did
             ,
             though
             not
             without
             some
             difficulty
             ,
             so
             order
             the
             matter
             ,
             that
             the
             blunter
             part
             of
             the
             Glass-drop
             was
             fastned
             to
             a
             stable
             Body
             (
             convey'd
             into
             the
             Receiver
             ,
             )
             and
             the
             crooked
             Stem
             was
             tyed
             to
             one
             end
             of
             a
             string
             ,
             whose
             other
             end
             was
             fastned
             to
             the
             Turning-key
             ;
             by
             which
             means
             ,
             when
             the
             Air
             had
             been
             diligently
             pump'd
             out
             ,
             the
             Stem
             was
             (
             by
             shortning
             the
             string
             )
             broken
             off
             ,
             and
             the
             Glass
             drop
             was
             shatter'd
             into
             a
             thousand
             pieces
             .
          
           
             This
             Experiment
             was
             long
             after
             repeated
             with
             the
             like
             success
             ,
             and
             having
             at
             that
             time
             no
             Gage
             to
             try
             how
             far
             the
             Air
             had
             been
             drawn
             out
             ,
             we
             let
             the
             external
             Air
             impell
             up
             the
             Water
             out
             of
             the
             Pump
             into
             the
             Receiver
             ,
             and
             thereby
             found
             ,
             that
             That
             vessel
             had
             not
             been
             negligently
             exhausted
             .
          
        
         
           
             EXPERIMENT
             XLIII
             .
          
           
             About
             the
             production
             of
             Light
             in
             the
             exhausted
             Receiver
             .
          
           
             I
             Presume
             ,
             I
             need
             not
             put
             Your
             Lordship
             in
             mind
             ,
             that
             divers
             attempts
             were
             made
             to
             try
             ,
             whether
             either
             a
             Flame
             ,
             or
             kindled
             Coals
             would
             be
             made
             to
             continue
             for
             sometime
             burning
             in
             our
             Receiver
             :
             But
             those
             Tryals
             making
             it
             evident
             ,
             that
             it
             would
             be
             either
             impossible
             ,
             or
             very
             difficult
             to
             produce
             any
             durable
             Light
             ,
             without
             the
             presence
             of
             the
             Air
             ,
             by
             the
             burning
             of
             bodies
             ;
             I
             thought
             it
             not
             amiss
             ,
             considering
             the
             Nobleness
             of
             Light
             ,
             to
             make
             trial
             ,
             whether
             it
             might
             be
             otherwise
             produc'd
             in
             our
             exhausted
             Receiver
             ;
             since
             whether
             or
             no
             the
             Attempts
             should
             prove
             successful
             ,
             the
             Event
             would
             probably
             be
             instructive
             .
             For
             as
             t
             is
             the
             property
             of
             Light
             ,
             when
             t
             is
             produc'd
             ,
             to
             be
             discoverable
             by
             it self
             ;
             so
             in
             such
             a
             Tryal
             as
             we
             intended
             ,
             it
             would
             teach
             something
             concerning
             Light
             ,
             to
             find
             that
             the
             absence
             of
             the
             Air
             would
             or
             would
             
             not
             hinder
             it
             from
             being
             produc'd
             .
             In
             prosecution
             of
             this
             Design
             ,
             knowing
             that
             hard
             Sugar
             ,
             being
             nimbly
             scrap'd
             with
             a
             knife
             ,
             will
             afford
             a
             sparkling
             Light
             ,
             so
             that
             now
             &
             then
             one
             would
             think
             that
             sparks
             of
             Fire
             fly
             from
             it
             ;
             we
             caus'd
             a
             good
             lump
             of
             hard
             Loaf-sugar
             to
             be
             conveniently
             and
             firmly
             placed
             in
             the
             cavity
             of
             our
             capp'd
             Receiver
             ,
             and
             to
             the
             vertical
             Cylinder
             formerly
             mentioned
             we
             caus'd
             to
             be
             fastned
             some
             pieces
             of
             a
             Steel-spring
             ,
             which
             being
             not
             very
             thick
             ,
             might
             in
             their
             passage
             along
             the
             Sugar
             ,
             grate
             ,
             or
             rub
             forceably
             against
             it
             ,
             and
             then
             the
             Receiver
             being
             diligently
             exhausted
             in
             the
             Night-time
             ,
             and
             in
             a
             dark
             Room
             ,
             the
             vertical
             Cylinder
             (
             whose
             lower
             Axis
             was
             inserted
             into
             the
             often
             mentioned
             Trencher
             )
             was
             made
             for
             a
             pretty
             while
             to
             move
             round
             by
             the
             help
             of
             the
             Turning-key
             ,
             
             manag'd
             by
             a
             hand
             steady
             and
             strong
             enough
             .
             By
             which
             means
             the
             Irons
             that
             came
             out
             of
             the
             vertical
             Cylinder
             ,
             making
             in
             their
             passage
             vigorous
             impressions
             upon
             the
             Sugar
             that
             stood
             somewhat
             in
             their
             way
             ,
             there
             were
             manifestly
             produc'd
             a
             good
             number
             of
             litle
             flashes
             ,
             and
             sometimes
             too
             ,
             though
             not
             frequently
             ,
             there
             seem'd
             to
             be
             struck
             off
             litle
             sparks
             of
             Fire
             .
          
        
         
           
             EXPERIMENT
             XLIV
             .
          
           
             About
             the
             production
             of
             a
             kind
             of
             Halo
             ,
             and
             Colours
             in
             the
             Exhausted
             Receiver
             .
          
           
             VVE
             took
             a
             large
             inverted
             Cucurbite
             for
             a
             Receiver
             ,
             which
             being
             so
             well
             wip'd
             both
             within
             and
             without
             as
             to
             be
             very
             clear
             ,
             allow'd
             me
             to
             observe
             ,
             and
             to
             make
             others
             do
             so
             too
             ,
             That
             when
             the
             Pump
             began
             to
             be
             set
             a
             work
             ,
             if
             I
             caus'd
             a
             pretty
             large
             Candle
             to
             be
             held
             on
             the
             other
             side
             of
             the
             Glass
             ,
             upon
             the
             turning
             of
             the
             Stop-cock
             to
             let
             the
             Air
             out
             of
             the
             Receiver
             into
             the
             Cylinder
             ,
             the
             Glass
             would
             seem
             to
             be
             full
             of
             Fumes
             ,
             and
             there
             would
             appear
             about
             the
             Flame
             of
             the
             Candle
             ,
             seen
             through
             them
             ,
             
             a
             kind
             of
             Halo
             ,
             that
             at
             first
             commonly
             was
             between
             Blew
             and
             Green
             ,
             and
             after
             some
             Sucks
             would
             be
             of
             a
             Reddish
             or
             Orange
             colour
             ,
             and
             both
             very
             vivid
             .
             The
             production
             of
             this
             Meteor
             (
             if
             I
             may
             so
             call
             it
             )
             was
             ,
             according
             to
             my
             conjecture
             ,
             made
             on
             some
             such
             score
             as
             this
             .
             That
             the
             Cement
             being
             somewhat
             soft
             and
             new
             (
             as
             is
             convenient
             for
             this
             Experiment
             )
             abounds
             with
             Turpentine
             ,
             and
             having
             a
             litle
             (
             as
             well
             to
             fasten
             on
             the
             Receiver
             ,
             as
             for
             the
             other
             purpose
             )
             apply'd
             to
             it
             a
             hot
             Iron
             ,
             whereby
             the
             Cement
             was
             both
             softned
             and
             heated
             ,
             it
             seem'd
             rational
             to
             expect
             ,
             That
             upon
             the
             withdrawing
             of
             the
             Air
             in
             the
             Receiver
             ,
             the
             Aerial
             Particles
             in
             the
             Cement
             ,
             freed
             from
             their
             former
             Pressure
             ,
             would
             extricate
             themselves
             ,
             and
             with
             the
             looser
             steams
             of
             the
             Turpentine
             and
             perhaps
             of
             the
             Bees-wax
             would
             with
             a
             kind
             of
             Explosion
             expand
             themselves
             in
             the
             Receiver
             ,
             and
             by
             their
             interposition
             between
             the
             Light
             and
             the
             Eye
             exhibit
             those
             delightful
             Colours
             we
             had
             seen
             .
             To
             confirme
             which
             ,
             I
             afterwards
             found
             ,
             that
             by
             watchfully
             observing
             it
             I
             could
             plainly
             enough
             perceive
             the
             colouring
             steams
             ,
             just
             upon
             the
             turning
             of
             the
             Stopcock
             ,
             to
             fly
             up
             from
             the
             Cement
             towards
             the
             top
             of
             the
             Glass
             ;
             and
             if
             we
             continued
             Pumping
             ,
             the
             Receiver
             would
             grow
             clearer
             ,
             and
             the
             Colours
             more
             dilute
             ,
             (
             till
             we
             had
             occasion
             to
             put
             on
             the
             Receiver
             ,
             and
             heat
             the
             Cement
             afresh
             :
             )
             of
             which
             the
             reason
             might
             be
             ,
             partly
             that
             the
             Aerial
             and
             Volatile
             Particles
             of
             the
             upper
             part
             of
             the
             Cement
             did
             in
             that
             tract
             of
             time
             spend
             themselves
             more
             and
             more
             ;
             and
             partly
             ,
             because
             the
             Agitation
             they
             receiv'd
             from
             the
             heat
             communicated
             by
             the
             Iron
             did
             continually
             decay
             .
             Not
             to
             mention
             ,
             that
             when
             the
             Receiver
             is
             more
             exhausted
             ,
             the
             want
             of
             Air
             makes
             it
             more
             difficult
             for
             Steams
             to
             be
             supported
             ,
             and
             as
             it
             were
             swim
             up
             and
             down
             in
             it
             .
          
           
             But
             for
             farther
             Confirmation
             ,
             I
             caus'd
             some
             Cement
             to
             be
             put
             into
             a
             small
             Crucible
             ,
             warm
             enough
             to
             melt
             it
             ;
             and
             conveying
             this
             into
             a
             clear
             Receiver
             of
             a
             convenient
             shape
             and
             size
             ,
             I
             caus'd
             the
             Pump
             to
             be
             set
             a
             work
             ;
             whereupon
             it
             appear'd
             manifestly
             enough
             ,
             That
             upon
             the
             opening
             of
             the
             Stop-cock
             to
             let
             out
             the
             
             Air
             ,
             the
             Steams
             would
             copiously
             be
             thrown
             about
             from
             the
             Crucible
             into
             the
             capacity
             of
             the
             Receiver
             ,
             and
             would
             ,
             after
             having
             a
             litle
             play'd
             there
             ,
             fall
             down
             again
             .
             But
             in
             these
             apparitions
             the
             Vividness
             ,
             and
             sometimes
             the
             Kind
             of
             the
             exhibited
             Colours
             seem'd
             much
             to
             depend
             upon
             divers
             circumstances
             ,
             such
             as
             the
             degrees
             of
             Heat
             ,
             the
             bigness
             and
             shape
             of
             the
             Receiver
             ,
             the
             quantity
             of
             Air
             that
             yet
             remain'd
             unpump'd
             out
             ,
             and
             the
             nature
             of
             the
             Cement
             its
             self
             ;
             which
             last
             particular
             I
             the
             rather
             mention
             ,
             because
             ,
             though
             I
             were
             hinder'd
             from
             doing
             it
             ,
             I
             had
             thoughts
             to
             try
             a
             suspicion
             I
             had
             ,
             that
             by
             varying
             the
             Materials
             expos'd
             to
             this
             kind
             of
             operation
             ,
             some
             pretty
             variety
             might
             be
             made
             in
             the
             phaenomena
             of
             the
             Experiment
             .
          
           
             Whether
             or
             no
             the
             Apparition
             of
             Whiteness
             ,
             or
             Light
             ,
             that
             we
             sometimes
             hapned
             to
             take
             notice
             of
             divers
             years
             agoe
             ,
             and
             have
             mentioned
             in
             the
             already
             *
             publish'd
             part
             of
             our
             Physico-mechanical
             Experiments
             ,
             may
             be
             partly
             (
             though
             not
             entirely
             )
             referr'd
             to
             some
             of
             the
             Cements
             I
             then
             imploy'd
             ,
             differing
             from
             those
             I
             now
             use
             most
             ,
             and
             to
             the
             unheeded
             temper
             of
             those
             Cements
             ,
             as
             to
             Warmth
             ,
             and
             degrees
             of
             Softness
             ,
             is
             a
             Doubt
             that
             further
             Observation
             may
             possibly
             enable
             us
             to
             determine
             .
          
        
         
           
             EXPERIMENT
             XLV
             .
          
           
             About
             the
             production
             of
             Heat
             by
             Attrition
             in
             the
             Exhausted
             Receiver
             .
          
           
             THe
             opinion
             that
             ascribes
             the
             Incalescence
             of
             solid
             Bodies
             ,
             struck
             or
             rubb'd
             hard
             against
             one
             another
             to
             the
             attrition
             or
             vehement
             agitation
             of
             the
             intercepted
             Air
             ,
             is
             famous
             and
             received
             enough
             to
             seem
             worthy
             of
             a
             particular
             Examination
             .
             But
             I
             confess
             to
             Your
             Lordship
             ,
             that
             t
             was
             not
             any
             thing
             relating
             to
             this
             Opinion
             that
             chiefly
             induc'd
             me
             to
             make
             the
             Experiment
             I
             am
             now
             about
             to
             give
             an
             account
             of
             ;
             for
             I
             thought
             it
             might
             be
             usefull
             
             to
             more
             purposes
             than
             one
             ,
             to
             be
             able
             to
             produce
             by
             Attrition
             a
             somewhat
             durable
             Heat
             even
             in
             our
             exhausted
             Receiver
             :
             and
             therefore
             though
             't
             were
             easie
             to
             foresee
             ,
             that
             it
             would
             prove
             no
             easie
             task
             ,
             yet
             we
             thought
             fit
             to
             attempt
             it
             in
             spight
             of
             the
             difficulties
             met
             with
             at
             our
             first
             Tryal
             .
             In
             what
             way
             and
             with
             what
             success
             we
             afterwards
             made
             this
             attempt
             ,
             I
             now
             proceed
             to
             relate
             .
          
           
             Cross
             the
             stable
             Trencher
             ,
             
             formerly
             often
             mentioned
             ,
             there
             was
             fastned
             a
             pretty
             strong
             Spring
             of
             Steel
             or
             Iron
             ,
             shap'd
             almost
             like
             the
             Lathe
             of
             a
             Cross-bow
             ,
             and
             to
             the
             midst
             of
             this
             Spring
             was
             strongly
             fastned
             on
             the
             outside
             a
             round
             piece
             of
             Brass
             hollow'd
             almost
             like
             a
             concave
             Burning-glass
             ,
             or
             one
             of
             those
             Tools
             wherein
             they
             use
             to
             grind
             Eye-Glasses
             for
             Telescopes
             .
             To
             this
             piece
             of
             Brass
             ,
             which
             was
             not
             considerably
             thick
             ,
             nor
             above
             2
             inches
             Diameter
             ,
             was
             fitted
             a
             convex
             piece
             of
             the
             same
             Metal
             ,
             almost
             like
             a
             Gage
             for
             a
             Tool
             to
             grind
             Glasses
             in
             ,
             which
             had
             belonging
             to
             it
             a
             square
             Handle
             ,
             whereinto
             as
             into
             a
             Socket
             was
             inserted
             a
             square
             piece
             of
             Wood
             ,
             proceeding
             from
             the
             Basis
             of
             a
             square
             wooden
             Pillar
             ,
             which
             we
             made
             use
             of
             on
             this
             occasion
             in
             stead
             of
             our
             vertical
             Cylinder
             .
             By
             the
             help
             of
             another
             piece
             of
             Wood
             coming
             from
             the
             other
             Basis
             of
             the
             same
             Pillar
             ,
             the
             Turning-key
             was
             joyned
             to
             this
             Pillar
             ,
             which
             was
             made
             of
             such
             a
             length
             ,
             that
             when
             the
             Turning-key
             was
             forceably
             kept
             down
             as
             low
             as
             the
             Brass
             Cover
             ,
             it
             was
             a
             part
             of
             ,
             would
             permit
             ;
             the
             convex
             piece
             of
             Metal
             lately
             describ'd
             did
             depress
             the
             concave
             piece
             a
             pretty
             way
             ,
             notwithstanding
             a
             vigorous
             resistance
             of
             the
             subjacent
             Spring
             .
          
           
             Besides
             these
             things
             ,
             a
             litle
             fine
             powder
             of
             Emery
             was
             put
             between
             the
             convex
             and
             concave
             pieces
             of
             Brass
             ,
             to
             make
             them
             more
             congruous
             ,
             and
             facilitate
             the
             motion
             that
             was
             to
             be
             made
             ;
             and
             there
             was
             fastned
             to
             the
             upper
             part
             of
             the
             Turning
             key
             a
             good
             Wimble
             ,
             without
             which
             we
             presum'd
             the
             turning
             of
             the
             Key
             would
             not
             produce
             a
             sufficient
             motion
             :
             in
             order
             to
             the
             making
             of
             which
             ,
             it
             was
             ,
             after
             the
             first
             Tryal
             ,
             judged
             requisite
             to
             have
             a
             strong
             man
             ,
             that
             was
             us'd
             to
             exercise
             his
             hands
             and
             armes
             in
             Mechanical
             
             labours
             ,
             upon
             which
             account
             we
             sent
             for
             a
             certain
             Lock-smith
             ,
             that
             was
             a
             lusty
             and
             dexterous
             fellow
             .
          
           
             All
             things
             that
             were
             thought
             necessary
             being
             thus
             in
             readiness
             ,
             and
             a
             Mercurial
             Gage
             being
             convey'd
             into
             the
             Receiver
             ,
             we
             caus'd
             the
             Air
             to
             be
             diligently
             pump'd
             out
             ;
             and
             then
             the
             Smith
             was
             order'd
             to
             turn
             the
             Wimble
             ,
             and
             to
             continue
             to
             lean
             a
             litle
             on
             it
             ,
             that
             he
             might
             be
             sure
             to
             keep
             the
             Turning-key
             from
             being
             at
             all
             lifted
             up
             by
             the
             formerly
             mentioned
             Spring
             .
          
           
             Whilst
             this
             man
             with
             much
             nimbleness
             and
             strength
             was
             moving
             the
             Wimble
             ,
             I
             watch'd
             the
             Gage
             ,
             to
             observe
             whether
             the
             agitation
             of
             the
             Stop-cock
             ,
             and
             consequently
             the
             Engine
             ,
             did
             not
             prejudice
             the
             Experiment
             ;
             and
             for
             greater
             caution
             I
             caus'd
             the
             Pump
             to
             be
             almost
             all
             the
             while
             kept
             at
             work
             ,
             though
             that
             seem'd
             not
             so
             necessary
             .
          
           
             When
             the
             Turner
             of
             the
             Wimble
             was
             almost
             out
             of
             Breath
             ,
             we
             let
             in
             for
             hast
             the
             Air
             at
             the
             Cover
             of
             the
             Receiver
             by
             lifting
             up
             the
             Turning-key
             ,
             and
             nimbly
             removing
             the
             Receiver
             we
             felt
             the
             pieces
             of
             Brass
             ,
             betwixt
             whom
             the
             Attrition
             had
             been
             made
             ,
             and
             ,
             as
             we
             expected
             ,
             found
             both
             of
             them
             very
             sensibly
             warm
             .
          
           
             But
             being
             willing
             to
             confirm
             the
             Experiment
             by
             a
             second
             Tryal
             ,
             which
             we
             hoped
             might
             ,
             after
             the
             Experience
             taught
             us
             by
             the
             first
             ,
             be
             somewhat
             better
             performed
             ,
             we
             caus'd
             the
             Smith
             ,
             after
             he
             had
             well
             refresh'd
             himself
             with
             rest
             and
             drink
             ,
             to
             lay
             hold
             of
             the
             Wimble
             again
             ,
             when
             the
             Gage
             made
             it
             appear
             that
             the
             Receiver
             was
             well
             exhausted
             ,
             so
             that
             by
             further
             Pumping
             the
             Quick-silver
             seem'd
             not
             to
             be
             further
             deprest
             .
             And
             in
             this
             2
             d
             Tryal
             the
             nimble
             Smith
             plaid
             his
             part
             so
             well
             ,
             (
             the
             Pump
             in
             the
             mean
             while
             not
             being
             neglected
             ,
             )
             that
             when
             we
             did
             as
             before
             hastily
             let
             in
             the
             Air
             ,
             and
             take
             out
             the
             Bodies
             that
             had
             been
             rubb'd
             against
             one
             another
             ,
             they
             were
             both
             of
             them
             (
             especially
             the
             uppermost
             )
             so
             hot
             ,
             that
             I
             could
             not
             endure
             to
             hold
             my
             hand
             on
             either
             of
             them
             ,
             and
             they
             did
             for
             a
             considerable
             time
             retain
             a
             not
             inconsiderable
             degree
             of
             Warmth
             .
          
           
             The
             same
             day
             I
             caus'd
             to
             be
             made
             at
             the
             Turners
             two
             bodies
             
             of
             Wood
             ,
             for
             size
             and
             shape
             like
             those
             of
             Brass
             we
             had
             just
             before
             imploy'd
             ;
             the
             upper
             of
             these
             was
             of
             hard
             Oak
             ,
             the
             other
             of
             Beech
             ,
             (
             such
             a
             difference
             between
             Woods
             ,
             to
             be
             heated
             by
             mutual
             Attrition
             ,
             being
             thought
             to
             be
             an
             advantageous
             circumstance
             ;
             )
             but
             though
             the
             Wimble
             was
             swiftly
             turn'd
             as
             before
             ,
             and
             that
             by
             the
             same
             Person
             ,
             nevertheless
             the
             Wood
             seem'd
             not
             to
             me
             (
             for
             all
             the
             By-standers
             were
             not
             of
             my
             opinion
             )
             to
             have
             manifestly
             acquired
             any
             Warmth
             ;
             and
             yet
             that
             there
             had
             been
             a
             considerable
             Attrition
             ,
             appear'd
             by
             the
             great
             Polish
             which
             part
             of
             the
             Wood
             had
             evidently
             acquir'd
             ,
             vvhich
             made
             me
             suspect
             ,
             that
             though
             the
             Wood
             seem'd
             dry
             enough
             ,
             yet
             it
             might
             not
             really
             be
             so
             ,
             notwithstanding
             the
             contrary
             was
             affirm'd
             to
             me
             :
             but
             not
             being
             willing
             to
             sit
             down
             with
             a
             single
             Tryal
             ,
             I
             caus'd
             the
             Experiment
             to
             be
             repeated
             with
             more
             obstinacy
             than
             before
             ,
             the
             effect
             of
             which
             was
             ,
             that
             the
             Wood
             ,
             especially
             the
             upper
             piece
             of
             it
             ,
             vvas
             brought
             to
             a
             Warmth
             unquestionably
             sensible
             .
          
        
         
           
             EXPERIMENT
             XLVI
             .
          
           
             About
             the
             slaking
             of
             Quick-Lime
             in
             the
             Exhausted
             Receiver
             .
          
           
             THe
             several
             Scopes
             I
             aim'd
             at
             in
             making
             the
             following
             Tryal
             are
             not
             necessary
             to
             be
             here
             particularly
             taken
             notice
             of
             .
             But
             one
             of
             them
             may
             be
             guess'd
             at
             by
             the
             subsequence
             of
             this
             Experiment
             to
             that
             immediately
             foregoing
             ,
             and
             the
             phaenomena
             of
             it
             may
             be
             mentioned
             in
             this
             Epistle
             upon
             the
             account
             of
             their
             being
             exhibited
             by
             our
             Engine
             .
          
           
             We
             took
             in
             an
             Evaporating
             Glass
             a
             convenient
             quantity
             of
             Water
             ,
             and
             having
             convey'd
             it
             into
             a
             Receiver
             ,
             and
             well
             drawn
             out
             the
             Air
             ,
             we
             let
             down
             into
             it
             by
             the
             Turning-key
             a
             lump
             of
             strong
             Lime
             ,
             about
             the
             bigness
             of
             a
             Pipin
             ;
             and
             observ'd
             not
             that
             at
             the
             first
             immersion
             ,
             nor
             for
             some
             while
             after
             ,
             there
             appear'd
             any
             
             considerable
             number
             of
             Bubbles
             ,
             but
             within
             about
             1
             /
             4
             of
             an
             hour
             ,
             as
             I
             guess'd
             it
             ,
             the
             Lime
             began
             (
             the
             Pump
             having
             been
             and
             being
             still
             ply'd
             from
             time
             to
             time
             )
             to
             slack
             with
             much
             violence
             ,
             and
             with
             bubbles
             wonderfully
             great
             ,
             that
             appear'd
             at
             each
             new
             Exuction
             ,
             so
             that
             the
             inside
             of
             the
             Receiver
             (
             though
             pretty
             large
             )
             was
             at
             length
             lin'd
             with
             Lime-water
             ,
             and
             a
             great
             part
             of
             the
             mixture
             did
             from
             time
             to
             time
             overflow
             the
             vessel
             ,
             that
             had
             purposely
             been
             but
             little
             fill'd
             ;
             nor
             did
             any
             thing
             but
             our
             weariness
             put
             a
             period
             to
             the
             bubling
             of
             the
             mixture
             ,
             whose
             heat
             was
             sensible
             even
             on
             the
             outside
             of
             the
             Receiver
             ,
             and
             which
             continued
             considerably
             hot
             in
             the
             Evaporating
             Glass
             for
             ¼
             of
             an
             hour
             (
             as
             I
             conjectured
             )
             after
             the
             Receiver
             was
             removed
             .
          
           
             Note
             ,
             That
             the
             Lime
             imployed
             about
             this
             Experiment
             was
             of
             a
             very
             good
             and
             strong
             kind
             (
             made
             of
             hard
             stones
             ,
             )
             and
             not
             such
             Lime
             ,
             made
             of
             Chalk
             ,
             as
             is
             commonly
             used
             at
             London
             ,
             which
             probably
             would
             not
             have
             been
             strong
             enough
             to
             have
             afforded
             us
             the
             same
             phaenomenon
             .
          
        
         
           
             EXPERIMENT
             XLVII
             .
          
           
             About
             an
             attempt
             made
             to
             measure
             the
             force
             of
             the
             Spring
             of
             included
             Air
             ,
             and
             examine
             a
             Conjecture
             about
             the
             difference
             of
             its
             strength
             in
             unequally
             broad
             mouth'd
             Vessels
             .
          
           
             THough
             several
             of
             the
             foregoing
             Tryals
             have
             sufficiently
             manifested
             that
             the
             Spring
             of
             the
             Air
             in
             its
             natural
             or
             wonted
             state
             ,
             hath
             a
             force
             very
             considerable
             ,
             and
             indeed
             much
             Greater
             than
             men
             seem
             to
             have
             hitherto
             believed
             ;
             Yet
             I
             could
             not
             hope
             by
             any
             of
             these
             Experiments
             to
             determine
             by
             any
             known
             weight
             ,
             how
             Great
             that
             force
             is
             ,
             so
             as
             to
             conclude
             that
             it
             is
             equivalent
             to
             such
             a
             Weight
             ,
             as
             so
             many
             Pounds
             ,
             Ounces
             ,
             &c.
             and
             to
             no
             more
             .
             Wherefore
             among
             the
             Uses
             I
             had
             design'd
             to
             make
             of
             our
             Syringe
             ,
             formerly
             often
             mentioned
             ,
             it
             was
             One
             ,
             to
             try
             if
             by
             the
             help
             
             of
             that
             Instrument
             ,
             we
             could
             determine
             somewhat
             near
             (
             for
             no
             more
             was
             to
             be
             expected
             )
             how
             much
             Weight
             a
             Cylinder
             of
             uncomprest
             Air
             included
             in
             it
             ,
             and
             consequently
             of
             the
             same
             Diameter
             vvith
             the
             cavity
             of
             the
             Barrel
             ,
             would
             be
             able
             to
             sustain
             or
             also
             to
             lift
             up
             .
          
           
             In
             order
             to
             this
             Tryal
             ,
             1.
             we
             provided
             a
             stable
             Pedestal
             ,
             or
             Frame
             ,
             wherein
             the
             Syringe
             might
             be
             kept
             firm
             ,
             and
             erected
             .
             Next
             ,
             vve
             also
             provided
             a
             Weight
             of
             Lead
             shap'd
             like
             our
             Brass-hoop
             ,
             or
             Ring
             ,
             *
             formerly
             describ'd
             ,
             that
             by
             the
             advantage
             of
             its
             figure
             it
             might
             be
             made
             to
             hang
             down
             by
             strings
             from
             the
             top
             of
             the
             Handle
             of
             the
             Rammer
             ,
             and
             so
             press
             evenly
             enough
             on
             all
             sides
             ,
             without
             making
             the
             upper
             part
             of
             the
             instrument
             top-heavy
             .
             3.
             
             We
             took
             care
             to
             leave
             ,
             between
             the
             bottom
             of
             the
             Syringe
             (
             which
             was
             firmly
             clos'd
             with
             strong
             Cement
             )
             and
             that
             part
             of
             it
             where
             the
             Sucker
             was
             ,
             a
             convenient
             quantity
             of
             Air
             ,
             to
             expand
             its
             self
             ,
             and
             lift
             up
             the
             Weight
             ,
             when
             the
             Air
             external
             to
             that
             included
             Air
             should
             be
             pump'd
             out
             of
             the
             Receiver
             :
             And
             lastly
             ,
             the
             Handle
             of
             the
             Rammer
             (
             from
             which
             the
             Annular
             weight
             lately
             spoken
             of
             depended
             )
             was
             so
             fastned
             to
             the
             Turning-key
             of
             the
             Cover
             of
             the
             Receiver
             ,
             that
             the
             Weight
             might
             not
             compress
             the
             Air
             included
             in
             the
             Syringe
             ,
             but
             leave
             it
             in
             its
             natural
             state
             or
             wonted
             Laxity
             ,
             till
             the
             Air
             were
             withdrawn
             from
             the
             Receiver
             .
          
           
             But
             notwithstanding
             all
             this
             ,
             when
             we
             actually
             tryed
             the
             Experiment
             ,
             That
             hapned
             which
             I
             feared
             .
             For
             though
             by
             this
             method
             the
             included
             Air
             would
             well
             enough
             lift
             up
             a
             Weight
             of
             7
             or
             8
             pound
             ,
             yet
             when
             the
             Rammer
             came
             to
             be
             clogg'd
             with
             so
             considerable
             a
             Weight
             ,
             as
             my
             scope
             in
             making
             the
             Experiment
             required
             ,
             the
             Instrument
             prov'd
             not
             so
             stanch
             ,
             but
             that
             it
             was
             easier
             for
             some
             particles
             of
             Air
             to
             force
             themselves
             a
             passage
             ,
             and
             get
             away
             between
             the
             Sucker
             and
             the
             inside
             of
             the
             Barrel
             ,
             than
             to
             heave
             up
             so
             great
             a
             Weight
             .
             And
             yet
             I
             have
             thought
             fit
             to
             relate
             the
             Experiment
             thus
             particularly
             ,
             because
             ,
             if
             an
             exact
             Syringe
             can
             be
             procured
             ,
             (
             which
             I
             fear
             will
             be
             very
             difficult
             ,
             but
             do
             not
             
             think
             impossible
             ,
             this
             seems
             to
             be
             one
             of
             the
             likeliest
             and
             least
             exceptionable
             wayes
             I
             know
             ,
             of
             measuring
             the
             force
             of
             the
             Airs
             Spring
             .
          
           
             But
             despairing
             to
             get
             such
             a
             Syringe
             ,
             as
             I
             desir'd
             ,
             in
             the
             place
             where
             I
             then
             was
             ,
             I
             bethought
             my self
             of
             another
             way
             ,
             by
             which
             I
             hop'd
             to
             be
             able
             (
             though
             not
             to
             arrive
             at
             an
             exact
             knowledge
             of
             the
             full
             force
             of
             the
             Airs
             Spring
             ,
             yet
             )
             at
             least
             to
             approach
             nearer
             it
             than
             I
             have
             been
             able
             to
             do
             by
             the
             help
             of
             the
             Syringe
             .
             For
             this
             purpose
             considering
             with
             my self
             ,
             that
             if
             a
             convenient
             quantity
             of
             Air
             were
             included
             in
             a
             fine
             small
             Bladder
             ,
             the
             sides
             of
             it
             would
             hinder
             the
             Air
             from
             getting
             away
             ,
             and
             the
             limberness
             of
             them
             would
             permit
             the
             Air
             to
             accommodate
             it self
             and
             the
             Bladder
             to
             the
             Figure
             of
             a
             Cylindrical
             vessel
             ,
             into
             which
             it
             might
             be
             put
             .
          
           
             Wherefore
             with
             much
             adoe
             I
             procured
             to
             be
             made
             by
             a
             person
             exercised
             in
             Turning
             a
             couple
             of
             hollow
             Cylinders
             ,
             whose
             sides
             were
             of
             a
             sufficient
             thickness
             ,
             (
             that
             they
             might
             resist
             the
             pressure
             of
             the
             Air
             to
             be
             imprisoned
             in
             them
             ,
             )
             and
             of
             such
             differing
             breadths
             ,
             that
             the
             first
             had
             but
             one
             inch
             in
             Diameter
             ,
             and
             the
             2
             d
             two
             ;
             their
             depths
             being
             also
             unequal
             ,
             that
             the
             one
             might
             receive
             a
             much
             larger
             Bladder
             than
             the
             other
             .
          
           
             With
             the
             lesser
             of
             these
             (
             which
             was
             very
             carefully
             Turned
             )
             I
             made
             a
             diligent
             Tryal
             ;
             whose
             Circumstances
             I
             cannot
             now
             acquaint
             Your
             Lordship
             with
             ,
             the
             Paper
             ,
             wherein
             they
             vvere
             amply
             recorded
             ,
             having
             been
             vvith
             other
             Notes
             belonging
             to
             this
             Continuation
             unluckily
             lost
             :
             but
             the
             most
             considerable
             things
             in
             the
             Event
             were
             ,
             That
             t
             was
             very
             difficult
             to
             procure
             a
             Bladder
             small
             and
             fine
             enough
             for
             that
             litle
             Cylinder
             ;
             and
             that
             one
             ,
             which
             at
             length
             we
             procured
             ,
             would
             not
             continue
             stanch
             for
             many
             Tryals
             ,
             but
             would
             after
             a
             vvhile
             part
             with
             a
             litle
             Air
             in
             the
             well
             exhausted
             Receiver
             ,
             when
             t
             was
             clog'd
             with
             the
             utmost
             Weight
             it
             could
             sustain
             :
             but
             whilst
             it
             continued
             stanch
             vve
             made
             one
             fair
             Tryal
             vvith
             it
             ,
             from
             vvhence
             vve
             concluded
             ,
             that
             a
             Cylinder
             of
             Air
             of
             but
             an
             inch
             in
             Diameter
             ,
             and
             lesse
             than
             two
             inches
             in
             length
             ,
             was
             
             able
             to
             raise
             visibly
             (
             though
             but
             a
             litle
             )
             a
             Weight
             of
             above
             ten
             Pounds
             ,
             (
             I
             speak
             of
             Averdupoiz
             vveights
             ,
             vvhere
             a
             Pound
             contains
             16
             ounces
             .
             )
             The
             manner
             of
             making
             this
             Experiment
             ,
             and
             the
             cautions
             us'd
             in
             judging
             of
             it
             ,
             Your
             Lorship
             may
             learn
             by
             the
             recital
             of
             the
             subsequent
             Tryal
             ;
             my
             Notes
             about
             which
             were
             not
             so
             unfortunate
             as
             those
             that
             concern'd
             the
             former
             .
          
           
             Into
             a
             hollow
             Cylinder
             of
             Wood
             of
             four
             inches
             in
             depth
             ,
             
             and
             two
             in
             Diameter
             ,
             furnished
             with
             a
             broad
             and
             solid
             bottom
             or
             Pedestal
             ,
             to
             make
             it
             stand
             the
             firmer
             ,
             was
             put
             a
             Lambs
             or
             Sheeps
             bladder
             very
             strongly
             tyed
             at
             the
             Neck
             ,
             on
             vvhich
             vvas
             put
             a
             Wooden
             Plug
             ,
             markt
             with
             Ink
             where
             the
             Edg
             of
             the
             Cylinder
             vvas
             contiguous
             to
             it
             ;
             this
             Plug
             being
             loaded
             with
             Weights
             ,
             amounting
             to
             35
             pound
             ,
             (
             the
             uppermost
             of
             vvhich
             Weights
             was
             fastned
             to
             the
             Turning-key
             ,
             to
             keep
             it
             upright
             ,
             and
             to
             help
             to
             raise
             it
             at
             first
             ,
             )
             the
             Receiver
             vvas
             exhausted
             ,
             till
             the
             Mark
             appeared
             very
             manifestly
             above
             the
             brim
             of
             the
             Cylinder
             ;
             and
             then
             ,
             though
             the
             string
             were
             by
             turning
             the
             Key
             quite
             slackned
             ,
             yet
             the
             mark
             on
             the
             Plug
             continued
             very
             visible
             :
             and
             vvhen
             so
             much
             Air
             was
             let
             into
             the
             Receiver
             ,
             as
             made
             the
             Weight
             depress
             the
             Plug
             quite
             beneath
             the
             Mark
             ,
             upon
             the
             repumping
             out
             of
             the
             Air
             the
             Weight
             was
             without
             the
             help
             of
             any
             Turning-key
             lifted
             up
             ,
             and
             by
             degrees
             all
             the
             mark
             on
             the
             Plug
             was
             raised
             about
             3
             /
             8
             above
             the
             edge
             of
             the
             Cylinder
             .
          
           
             Wherefore
             we
             substituted
             for
             a
             7
             pound
             weight
             one
             that
             was
             estimated
             at
             14
             ,
             (
             for
             then
             we
             had
             not
             a
             Ballance
             strong
             enough
             to
             weigh
             it
             with
             ,
             )
             and
             using
             the
             same
             Bladder
             we
             repeated
             the
             Experiment
             ,
             onely
             having
             a
             care
             to
             support
             a
             litle
             the
             uppermost
             Weight
             by
             the
             Turning-key
             ,
             till
             the
             Bladder
             had
             attained
             its
             expansion
             ;
             and
             then
             the
             Weight
             being
             gently
             let
             go
             ,
             depress'd
             not
             the
             Plug
             so
             low
             ,
             but
             that
             we
             could
             yet
             see
             the
             mark
             on
             it
             ,
             (
             which
             yet
             was
             all
             we
             could
             do
             ,
             )
             though
             that
             part
             of
             the
             Plug
             ,
             where
             the
             mark
             vvas
             ,
             vvere
             manifestly
             more
             deprest
             than
             the
             other
             .
          
           
             For
             the
             clearing
             up
             of
             some
             particulars
             relating
             to
             this
             Tryal
             ,
             we
             will
             subjoyn
             the
             following
             Notes
             .
          
           
           
             1.
             
             The
             Plug
             is
             to
             be
             so
             fitted
             to
             the
             Cavity
             of
             the
             Cylinder
             ,
             as
             easily
             to
             slip
             up
             and
             down
             in
             it
             ,
             without
             Grating
             against
             the
             sides
             of
             it
             ,
             lest
             it
             needlesly
             increase
             the
             resistance
             of
             the
             Weight
             to
             be
             rais'd
             .
             And
             this
             Plug
             ought
             to
             be
             of
             a
             convenient
             length
             ,
             as
             about
             an
             inch
             and
             1
             /
             2
             at
             least
             ,
             that
             it
             may
             be
             the
             fitter
             to
             help
             to
             reduce
             the
             Bladder
             by
             compression
             into
             a
             somewhat
             Cylindrical
             shape
             ,
             and
             yet
             that
             it
             may
             not
             be
             thrust
             in
             too
             deep
             by
             the
             incumbent
             Weight
             ;
             and
             that
             the
             Weight
             might
             rest
             more
             firmly
             upon
             it
             ,
             there
             was
             a
             broad
             and
             strong
             Ledge
             made
             at
             the
             top
             of
             it
             ,
             by
             which
             it
             might
             lean
             on
             every
             side
             upon
             the
             brim
             of
             the
             hollow
             Cylinder
             .
          
           
             2.
             
             Before
             the
             Instrument
             was
             conveyed
             into
             the
             Receiver
             ,
             the
             Bladder
             (
             which
             ought
             to
             be
             of
             a
             just
             size
             ,
             and
             not
             full
             blown
             ,
             and
             of
             a
             fine
             and
             limber
             contexture
             )
             was
             put
             into
             the
             Cylinder
             ,
             and
             by
             divers
             gradual
             (
             but
             not
             immoderate
             )
             compressions
             was
             reduc'd
             to
             conform
             its
             self
             ,
             as
             much
             as
             might
             be
             ,
             to
             the
             Cylindrical
             shape
             of
             the
             containing
             vessel
             .
             And
             then
             the
             Weight
             being
             put
             on
             ,
             and
             taken
             off
             again
             ,
             there
             was
             a
             mark
             (
             in
             the
             form
             of
             an
             horizontally
             plac'd
             Arch
             )
             made
             with
             Ink
             ,
             where
             the
             edge
             of
             the
             brim
             of
             the
             hollow
             Cylinder
             did
             almost
             touch
             the
             Plug
             .
             This
             we
             thought
             necessary
             to
             do
             ,
             to
             avoid
             a
             mistake
             ;
             for
             we
             must
             not
             judg
             ,
             that
             all
             the
             Weight
             ,
             that
             might
             be
             rais'd
             by
             our
             Bladder
             ,
             may
             pass
             for
             the
             Weight
             sought
             after
             by
             our
             Experiment
             ;
             since
             the
             Air
             in
             the
             Bladder
             is
             by
             reason
             of
             the
             incumbent
             weight
             more
             comprest
             than
             t
             was
             before
             ,
             and
             consequently
             its
             being
             able
             to
             heave
             up
             a
             Great
             weight
             will
             not
             infer
             ,
             that
             our
             common
             Air
             is
             able
             in
             its
             natural
             state
             (
             as
             they
             call
             it
             )
             to
             exert
             so
             Great
             a
             strength
             ;
             that
             Weight
             being
             onely
             to
             be
             lookt
             on
             as
             rais'd
             or
             sustain'd
             by
             the
             uncomprest
             Air
             ,
             that
             is
             rais'd
             or
             sustain'd
             when
             the
             Plug
             is
             lifted
             up
             to
             the
             mark
             ,
             since
             till
             then
             the
             Spring
             of
             the
             Air
             does
             but
             bring
             it
             back
             from
             its
             new
             state
             of
             adventitious
             compression
             to
             its
             natural
             or
             wonted
             Laxity
             .
          
           
             3.
             
             When
             ,
             after
             the
             operation
             was
             ended
             ,
             we
             took
             the
             Bladder
             out
             of
             the
             vessel
             ,
             it
             had
             obtain'd
             a
             form
             Cylindrical
             enough
             ,
             
             and
             though
             it
             could
             be
             but
             2
             inches
             in
             Diameter
             ,
             yet
             it
             was
             so
             litle
             as
             to
             be
             but
             half
             an
             inch
             more
             long
             than
             broad
             .
          
           
             4.
             
             The
             reason
             why
             I
             chose
             to
             have
             the
             two
             Cylinders
             made
             of
             the
             unequal
             Diameters
             above
             mentioned
             ,
             was
             to
             examine
             ,
             as
             far
             as
             by
             this
             way
             I
             could
             ,
             a
             conjecture
             I
             had
             ,
             that
             the
             force
             of
             the
             Spring
             of
             differing
             Cylinders
             of
             Air
             to
             lift
             up
             solid
             Weights
             ,
             would
             ,
             
               at
               the
               very
               first
               raising
               of
               the
               Weights
               ,
            
             be
             in
             duplicate
             proportion
             to
             the
             Diameters
             of
             their
             Cylinders
             ,
             (
             those
             Diameters
             being
             proportionable
             to
             the
             Areas
             of
             the
             plain
             Superficies
             ,
             against
             which
             the
             Air
             does
             immediately
             press
             ,
             )
             without
             very
             much
             considering
             the
             inequality
             that
             may
             be
             between
             the
             quantity
             of
             the
             several
             parcels
             of
             Air
             ,
             whose
             pressures
             are
             compared
             .
             But
             t
             is
             to
             be
             remembred
             ,
             that
             I
             said
             
               at
               the
               very
               first
               raising
               of
               the
               weights
               ,
            
             because
             presently
             after
             That
             ,
             the
             quantity
             of
             the
             parcels
             of
             Air
             may
             be
             very
             considerable
             :
             for
             ,
             as
             I
             have
             shewn
             in
             another
             Treatise
             ,
             two
             very
             unequal
             quantities
             of
             Air
             being
             made
             by
             their
             Expansion
             to
             possess
             two
             equal
             spaces
             ,
             the
             lesser
             quantity
             of
             Air
             must
             be
             much
             more
             rarified
             in
             proportion
             than
             the
             greater
             ;
             and
             consequently
             ,
             (
             to
             bring
             this
             home
             to
             our
             present
             Argument
             )
             though
             both
             be
             lifted
             up
             ¼
             or
             ½
             of
             an
             inch
             ,
             the
             Spring
             of
             a
             very
             litle
             Air
             must
             be
             much
             more
             weakned
             than
             that
             of
             a
             very
             considerable
             Quantity
             ,
             and
             so
             it
             cannot
             continue
             to
             lift
             up
             its
             weight
             ,
             as
             the
             above
             mentioned
             proportion
             would
             (
             if
             it
             were
             not
             for
             this
             Advertisement
             )
             seem
             to
             require
             .
          
           
             Taking
             then
             our
             conjecture
             in
             the
             sense
             now
             declared
             ,
             the
             success
             of
             our
             Tryals
             is
             agreeable
             to
             it
             ,
             inviting
             us
             to
             conclude
             ,
             that
             the
             Air
             in
             the
             Bladder
             ,
             which
             was
             but
             two
             inches
             in
             Diameter
             ,
             was
             able
             by
             its
             Pressure
             to
             countervaile
             the
             weight
             of
             42
             pound
             ,
             which
             is
             about
             four
             times
             the
             weight
             that
             we
             lately
             observ'd
             the
             Spring
             of
             a
             Cylinder
             of
             Air
             of
             one
             inch
             in
             Diameter
             to
             be
             able
             to
             lift
             up
             .
             For
             though
             ,
             according
             to
             what
             we
             have
             formerly
             said
             of
             a
             duplicate
             proportion
             ,
             42
             pound
             seems
             to
             be
             somewhat
             more
             than
             ought
             to
             have
             been
             lifted
             up
             in
             the
             Cylinder
             of
             two
             inches
             bore
             ,
             when
             that
             of
             one
             inch
             lifted
             up
             not
             much
             above
             10
             pound
             ;
             
             yet
             this
             disagrees
             not
             with
             the
             Hypothesis
             ,
             if
             we
             consider
             that
             the
             substance
             of
             the
             Bladder
             straitens
             the
             cavity
             of
             the
             smaller
             Cylinder
             in
             a
             Greater
             proportion
             than
             that
             of
             the
             bigger
             .
          
           
             5.
             
             Though
             we
             have
             thus
             (
             as
             far
             as
             the
             Instruments
             we
             were
             able
             to
             procure
             would
             assist
             us
             )
             measured
             the
             Pressure
             of
             included
             Air
             ,
             yet
             I
             must
             not
             forbear
             to
             advertise
             Your
             Lordship
             ,
             that
             considering
             what
             I
             formerly
             observ'd
             to
             You
             about
             the
             weight
             of
             an
             Atmospherical
             Pillar
             of
             an
             inch
             in
             Diameter
             ,
             I
             cannot
             but
             think
             ,
             that
             if
             a
             Cylinder
             ,
             or
             other
             convenient
             instrument
             ,
             exactly
             Tite
             ,
             can
             be
             procured
             ,
             the
             Spring
             of
             an
             Aerial
             Cylinder
             will
             appear
             to
             be
             Greater
             than
             we
             found
             it
             by
             the
             foregoing
             Tryals
             ;
             in
             which
             I
             consider
             that
             ,
             not
             to
             mention
             the
             resistance
             of
             the
             Bladder
             its
             self
             ,
             the
             membraneous
             substance
             that
             lin'd
             the
             Cylinders
             (
             though
             t
             were
             very
             thin
             and
             fine
             )
             could
             not
             but
             somewhat
             straiten
             their
             Cavities
             ,
             and
             consequently
             somewhat
             (
             though
             not
             much
             )
             lessen
             the
             Diameters
             of
             the
             included
             Aerial
             Cylinders
             .
          
           
             6.
             
             To
             all
             these
             Notes
             I
             must
             adde
             this
             Advertisement
             ,
             That
             it
             may
             be
             therefore
             the
             more
             difficult
             in
             such
             Tryals
             as
             ours
             to
             ascertain
             the
             force
             of
             the
             Airs
             Spring
             ,
             because
             ,
             that
             Air
             its
             self
             when
             t
             is
             included
             ,
             being
             shut
             up
             with
             the
             Pressure
             of
             the
             Atmosphere
             upon
             it
             ,
             t
             is
             probable
             ,
             that
             since
             that
             Pressure
             (
             as
             we
             have
             shewn
             )
             is
             not
             at
             all
             times
             the
             same
             ,
             the
             Spring
             of
             the
             included
             Air
             will
             accordingly
             be
             varied
             .
             And
             ,
             if
             my
             memory
             fail
             me
             not
             ,
             when
             the
             lately
             recited
             Experiments
             were
             made
             ,
             our
             Barometer
             declared
             the
             Atmosphere
             to
             be
             somewhat
             light
             .
          
           
             From
             what
             has
             been
             hitherto
             delivered
             ,
             this
             may
             result
             ;
             that
             t
             is
             likely
             ,
             that
             the
             Spring
             of
             an
             Aerial
             Cylinder
             an
             inch
             broad
             ,
             may
             be
             able
             to
             sustain
             ,
             if
             not
             raise
             ,
             a
             pretty
             deal
             more
             than
             ten
             pound
             Weight
             ;
             and
             that
             the
             past
             Tryals
             ,
             without
             determining
             that
             the
             Air
             can
             raise
             no
             more
             than
             in
             them
             it
             did
             ,
             do
             ,
             at
             least
             ,
             prove
             that
             it
             can
             raise
             up
             as
             much
             Weight
             as
             we
             have
             related
             ,
             since
             we
             actually
             found
             it
             to
             do
             so
             .
          
        
         
           
           
             EXPERIMENT
             XLVIII
             .
          
           
             About
             an
             easie
             way
             of
             making
             a
             small
             quantity
             of
             included
             Air
             raise
             in
             the
             exhausted
             Receiver
             50
             or
             60
             pound
             ,
             or
             a
             greater
             weight
             .
          
           
             I
             Would
             very
             willingly
             have
             further
             prosecuted
             the
             foregoing
             Tryals
             ,
             to
             see
             how
             far
             the
             lately
             propos'd
             Conjecture
             or
             Hypothesis
             would
             hold
             ;
             but
             was
             hindered
             by
             the
             want
             of
             Receivers
             tall
             and
             capacious
             enough
             to
             contain
             the
             Weights
             ,
             that
             such
             an
             attempt
             required
             :
             but
             remembring
             that
             there
             were
             not
             any
             Experiments
             made
             in
             our
             Engine
             ,
             that
             appear'd
             more
             strange
             to
             the
             Generality
             of
             Spectators
             ,
             and
             serv'd
             more
             to
             give
             them
             a
             high
             opinion
             of
             the
             Airs
             Spring
             ,
             than
             those
             wherein
             they
             saw
             solid
             Bodies
             actually
             lifted
             up
             by
             it
             ,
             and
             remembring
             ,
             that
             I
             had
             lying
             by
             me
             a
             Brass
             vessel
             ,
             (
             which
             had
             been
             bespoken
             for
             another
             Experiment
             ,
             for
             which
             the
             Workmen
             had
             not
             made
             it
             fit
             ,
             )
             I
             thought
             it
             not
             amiss
             to
             imploy
             it
             about
             making
             a
             Tryal
             very
             easie
             ,
             and
             yet
             fit
             to
             be
             shewn
             to
             Strangers
             ,
             to
             convince
             them
             ,
             that
             the
             Spring
             of
             the
             Air
             is
             a
             much
             more
             considerable
             thing
             than
             they
             imagined
             .
          
           
             We
             took
             then
             a
             Brass
             vessel
             made
             like
             a
             Cylinder
             ,
             and
             having
             one
             of
             his
             Orifices
             exactly
             covered
             with
             a
             flat
             Plate
             very
             firmly
             fastned
             to
             it
             ,
             the
             other
             Orifice
             being
             wide
             open
             .
             The
             depth
             of
             this
             vessel
             was
             4
             inches
             ,
             and
             the
             Diameter
             should
             have
             been
             precisely
             (
             but
             wanted
             about
             a
             quarter
             of
             an
             inch
             of
             )
             4
             inches
             .
             To
             this
             hollow
             Cylinder
             we
             fitted
             a
             wooden
             Plug
             ,
             like
             one
             of
             those
             described
             in
             the
             foregoing
             Experiment
             ,
             save
             that
             it
             was
             not
             quite
             so
             long
             ,
             and
             that
             it
             was
             furnished
             with
             a
             Rimme
             or
             Lip
             ,
             which
             was
             purposely
             made
             of
             a
             considerable
             breadth
             ,
             that
             it
             might
             afford
             a
             stable
             Basis
             to
             the
             Weight
             that
             should
             lean
             upon
             it
             .
             And
             then
             taking
             a
             middle
             siz'd
             and
             limber
             Bladder
             ,
             strongly
             tyed
             at
             the
             Neck
             ,
             but
             not
             near
             full
             blown
             ,
             we
             press'd
             it
             by
             the
             help
             of
             
             the
             Plug
             into
             the
             Cylinder
             to
             make
             it
             the
             better
             accommodate
             it self
             to
             the
             figure
             of
             it
             .
             Then
             taking
             notice
             by
             an
             inky
             mark
             how
             much
             of
             the
             Plug
             was
             extant
             above
             the
             orifice
             of
             the
             vessel
             ,
             
             we
             laid
             the
             Weights
             upon
             the
             Plug
             ,
             (
             whose
             Rimme
             or
             Lip
             hinder'd
             it
             from
             being
             deprest
             too
             deep
             into
             the
             cavity
             of
             the
             vessel
             ;
             )
             and
             having
             convey'd
             them
             into
             the
             Receiver
             ,
             we
             found
             as
             we
             expected
             ,
             that
             if
             we
             had
             loaded
             the
             Plug
             but
             with
             a
             single
             Weight
             ,
             (
             as
             to
             avoid
             trouble
             ,
             and
             the
             danger
             of
             breaking
             the
             Glass
             we
             usually
             thought
             fit
             to
             do
             ,
             )
             though
             that
             were
             a
             common
             half
             hundred
             weight
             ,
             (
             which
             You
             know
             amounts
             to
             56
             pounds
             ,
             )
             it
             would
             very
             quickly
             be
             manifestly
             heav'd
             up
             by
             the
             Spring
             of
             the
             included
             Air.
             For
             confirmation
             of
             more
             than
             which
             ,
             I
             shall
             subjoyn
             the
             ensuing
             Tryal
             ,
             as
             I
             find
             it
             recorded
             among
             my
             loose
             Notes
             .
          
           
             The
             Weight
             that
             was
             lifted
             up
             by
             the
             Bladder
             in
             the
             Cylinder
             4
             inches
             broad
             ,
             was
             75
             pound
             ;
             this
             Weight
             was
             lifted
             up
             till
             the
             wooden
             Plug
             disclos'd
             the
             Mark
             ,
             that
             was
             to
             shew
             the
             height
             ,
             at
             which
             the
             Air
             kept
             the
             said
             Plug
             before
             it
             was
             comprest
             :
             disclos'd
             it
             I
             say
             visibly
             at
             the
             5
             th
             Exuction
             ,
             and
             at
             the
             7
             th
             that
             mark
             was
             ⅛
             ,
             or
             rather
             3
             /
             16
             above
             the
             Edge
             of
             the
             Cylinder
             .
             In
             the
             Gage
             where
             the
             Mercury
             in
             the
             open
             Air
             was
             wont
             to
             stand
             about
             ⅛
             above
             the
             uppermost
             Glass-mark
             ,
             it
             was
             deprest
             till
             it
             was
             ⅛
             below
             the
             second
             mark
             .
             When
             the
             Air
             was
             let
             in
             ,
             it
             was
             a
             pretty
             while
             before
             the
             Weight
             did
             manifestly
             begin
             to
             subside
             ;
             the
             Bladder
             being
             taken
             out
             ,
             and
             the
             place
             it
             had
             possess'd
             in
             the
             Cylinder
             being
             supply'd
             with
             a
             Sleeve
             ,
             or
             some
             such
             thing
             ,
             and
             the
             Weight
             laid
             again
             upon
             the
             Plug
             ,
             we
             found
             that
             at
             24
             Exuctions
             the
             Mercury
             was
             deprest
             to
             the
             lowest
             Mark
             of
             the
             Gage
             ;
             and
             it
             was
             the
             34
             or
             35
             th
             Exuction
             before
             the
             Receiver
             appear'd
             to
             be
             so
             exhausted
             ,
             as
             to
             put
             an
             end
             to
             the
             sinking
             of
             the
             Mercury
             ,
             which
             was
             then
             above
             ⅛
             beneath
             the
             lowest
             mark
             .
          
           
             Your
             Lordship
             will
             easily
             believe
             ,
             that
             most
             of
             the
             Spectators
             of
             such
             Tryals
             thought
             it
             somewhat
             strange
             to
             see
             a
             small
             quantity
             of
             Air
             ,
             which
             was
             not
             onely
             uncomprest
             in
             the
             Bladder
             ,
             but
             
             did
             not
             near
             fill
             it
             ,
             (
             and
             left
             it
             very
             soft
             and
             yielding
             to
             the
             least
             touch
             ,
             )
             lift
             up
             so
             easily
             by
             its
             bare
             Spring
             such
             Great
             Weights
             as
             indeavoured
             to
             oppress
             it
             .
             But
             this
             not
             being
             any
             thing
             near
             a
             sufficient
             Tryal
             ,
             how
             far
             the
             conjecture
             or
             Hypothesis
             formerly
             propos'd
             will
             hold
             ,
             I
             thought
             fit
             to
             make
             the
             utmost
             Tryals
             the
             tallest
             Receivers
             I
             could
             procure
             would
             admit
             :
             and
             having
             caus'd
             leaden
             weights
             to
             be
             purposely
             cast
             flat
             like
             Cheeses
             ,
             and
             as
             broad
             as
             we
             could
             conveniently
             put
             into
             the
             Receiver
             ,
             that
             by
             the
             advantage
             of
             this
             shape
             we
             might
             be
             able
             to
             pile
             up
             the
             more
             of
             them
             ,
             without
             much
             danger
             that
             any
             of
             them
             should
             be
             shaken
             down
             ;
             we
             laid
             divers
             of
             them
             one
             upon
             another
             ,
             and
             then
             the
             upper
             part
             of
             the
             Receiver
             growing
             too
             narrow
             to
             admit
             more
             of
             them
             ,
             we
             added
             a
             less
             broad
             Weight
             or
             two
             ;
             and
             then
             exhausting
             the
             Receiver
             ,
             till
             we
             perceiv'd
             by
             the
             Gage
             that
             the
             Air
             was
             manifestly
             withdrawn
             ,
             we
             found
             (
             as
             near
             as
             we
             could
             measure
             )
             by
             the
             help
             of
             a
             Mark
             and
             a
             pair
             of
             Compasses
             ,
             that
             the
             Plug
             was
             so
             far
             rais'd
             ,
             as
             that
             t
             was
             concluded
             ,
             that
             the
             Elevation
             vvould
             have
             been
             much
             Greater
             ,
             if
             the
             included
             Air
             ,
             being
             put
             upon
             so
             Great
             a
             Conatus
             ,
             had
             not
             found
             it
             easier
             to
             produce
             some
             Leak
             at
             the
             neck
             of
             the
             Bladder
             ,
             than
             to
             lift
             up
             so
             Great
             a
             Weight
             ,
             which
             by
             our
             Reckoning
             came
             to
             about
             100
             pound
             of
             16
             ounces
             to
             the
             pound
             .
             But
             this
             last
             Experiment
             ,
             for
             want
             of
             some
             requisite
             accommodations
             ,
             vve
             vvere
             hinder'd
             from
             repeating
             and
             promoting
             ;
             though
             the
             above
             mentioned
             Hypothesis
             made
             me
             presume
             ,
             that
             a
             far
             Greater
             weight
             might
             this
             way
             have
             been
             rais'd
             if
             the
             Bladder
             had
             been
             stanch
             ,
             and
             the
             Receiver
             high
             enough
             .
          
           
             I
             need
             not
             tell
             Your
             Lordship
             ,
             that
             if
             a
             larger
             Bladder
             be
             imploy'd
             and
             included
             in
             a
             Brass
             vessel
             of
             a
             sufficiently
             wide
             Orifice
             ,
             a
             far
             Greater
             weight
             may
             be
             lifted
             up
             by
             the
             Spring
             of
             the
             internal
             Air.
             But
             yet
             it
             will
             not
             be
             amiss
             to
             give
             Your
             Lordship
             on
             this
             occasion
             this
             Advertisement
             ,
             which
             may
             be
             fit
             to
             be
             taken
             notice
             of
             on
             divers
             others
             :
             That
             care
             must
             be
             had
             not
             to
             make
             Receivers
             ,
             that
             ought
             to
             be
             well
             emptied
             ,
             too
             large
             ,
             and
             especially
             too
             wide
             at
             the
             Orifice
             ;
             for
             otherwayes
             they
             will
             be
             expos'd
             to
             so
             
             great
             a
             Pressure
             of
             the
             Atmosphere
             ,
             that
             they
             need
             be
             of
             an
             extraordinary
             strength
             to
             resist
             it
             ;
             and
             even
             Receivers
             ,
             that
             seem'd
             thick
             enough
             proportionably
             to
             their
             bulk
             ,
             and
             which
             held
             out
             very
             well
             till
             the
             close
             of
             the
             Operation
             ,
             yet
             when
             they
             came
             to
             be
             very
             diligently
             exhausted
             ,
             they
             did
             ,
             by
             reason
             of
             the
             wideness
             of
             their
             Orifices
             ,
             begin
             to
             crack
             at
             the
             bottom
             .
          
        
         
           
             EXPERIMENT
             XLIX
             .
          
           
             IN
             one
             of
             my
             publish'd
             Experiments
             *
             I
             long
             since
             told
             Your
             Lordship
             ,
             that
             when
             I
             endeavoured
             ,
             by
             the
             help
             of
             a
             seal'd
             bubble
             ,
             weigh'd
             in
             an
             exhausted
             Receiver
             ,
             to
             compare
             the
             Gravity
             of
             Air
             and
             Water
             ,
             I
             was
             hinder'd
             by
             the
             casual
             breaking
             of
             the
             Glass
             from
             compleating
             the
             Experiment
             .
             Wherefore
             I
             afterwards
             thought
             fit
             to
             repeat
             the
             Tryal
             ;
             and
             though
             when
             I
             had
             done
             so
             twice
             or
             thrice
             ,
             having
             given
             away
             the
             large
             Receiver
             I
             had
             made
             use
             of
             about
             them
             ,
             and
             not
             being
             able
             ever
             since
             to
             procure
             a
             Good
             one
             ,
             that
             was
             capacious
             enough
             for
             the
             tender
             Scales
             I
             thought
             so
             nice
             an
             Experiment
             required
             ,
             I
             did
             not
             prosecute
             that
             Attempt
             so
             far
             as
             I
             intended
             ;
             yet
             this
             very
             difficulty
             I
             met
             with
             to
             procure
             the
             Requisites
             of
             making
             the
             Tryal
             ,
             invites
             me
             to
             subjoyn
             the
             two
             following
             Notes
             ,
             which
             I
             find
             among
             my
             loose
             Papers
             .
          
           
             We
             weigh'd
             a
             Bubble
             in
             the
             Receiver
             ,
             
             which
             we
             found
             to
             weigh
             above
             half
             a
             Grain
             heavier
             ,
             when
             much
             of
             the
             Air
             was
             exhausted
             ,
             than
             when
             it
             was
             full
             .
             Afterwards
             we
             took
             out
             this
             seal'd
             Bubble
             ,
             and
             weighing
             it
             found
             it
             to
             weigh
             68
             Grains
             and
             a
             half
             ;
             then
             breaking
             off
             the
             small
             tip
             of
             it
             under
             water
             ,
             we
             found
             that
             the
             heat
             ,
             by
             which
             it
             was
             seal'd
             up
             ,
             had
             rarifi'd
             its
             included
             Air
             ,
             so
             that
             it
             admitted
             125
             Grains
             of
             Water
             ,
             for
             the
             admitted
             Water
             and
             Glass
             weighed
             193
             ½
             Grains
             .
             Then
             filling
             it
             full
             with
             Water
             ,
             we
             found
             it
             to
             contain
             in
             all
             739
             Grains
             of
             Water
             ,
             for
             it
             weighed
             807
             1
             /
             2
             Grains
             :
             whence
             t
             is
             evident
             ,
             that
             the
             difference
             between
             
             the
             weight
             of
             Water
             and
             Air
             was
             less
             than
             1228
             to
             1.
             ]
          
           
             We
             weighed
             in
             the
             Receiver
             a
             Bubble
             ,
             
             the
             Glass
             of
             which
             weighed
             60
             Grains
             :
             the
             Air
             that
             fill'd
             it
             weighed
             
               in
               vacuo
            
             27
             /
             32
             of
             a
             Grain
             :
             the
             Water
             that
             fill'd
             it
             weighed
             720
             ¼
             Grains
             :
             So
             that
             by
             this
             Experiment
             the
             proportion
             of
             the
             weight
             of
             Air
             to
             Water
             is
             as
             (
             one
             )
             to
             (
             853
             17
             /
             27.
             )
          
           
             The
             Tryals
             mentioned
             in
             these
             Notes
             ,
             though
             they
             were
             too
             few
             for
             me
             to
             acquiesce
             in
             ,
             yet
             being
             made
             in
             a
             nevv
             vvay
             ,
             and
             which
             has
             some
             advantages
             above
             those
             that
             have
             been
             hitherto
             imployed
             to
             weigh
             the
             Air
             ,
             may
             yet
             serve
             to
             keep
             us
             from
             the
             contrary
             .
             Extremes
             ,
             that
             have
             not
             been
             avoided
             by
             such
             eminent
             Mathematicians
             as
             Galileo
             and
             Ricciolus
             ;
             the
             former
             of
             which
             makes
             Water
             to
             be
             but
             about
             400
             times
             as
             heavy
             the
             Air
             ;
             and
             the
             later
             ,
             whose
             conjecture
             is
             much
             remoter
             from
             the
             Truth
             ,
             10000
             times
             heavier
             .
          
           
             But
             it
             is
             so
             desireable
             a
             thing
             ,
             and
             may
             prove
             of
             such
             importance
             ,
             to
             know
             the
             proportion
             in
             Weight
             betwixt
             Air
             and
             Water
             ,
             that
             I
             shall
             not
             scruple
             to
             acquaint
             Your
             Lordship
             with
             an
             attempt
             or
             two
             that
             I
             made
             to
             discover
             it
             by
             another
             way
             :
             For
             ,
             though
             at
             first
             sight
             this
             Experiment
             may
             seem
             to
             be
             the
             same
             with
             one
             publish'd
             a
             pretty
             while
             ago
             in
             the
             learned
             Schottus
             his
             
               Mechanica
               Hydraulico
               pneumatica
            
             ;
             yet
             Your
             Lordship
             will
             easily
             perceive
             this
             difference
             between
             them
             :
             That
             ,
             whereas
             the
             industrious
             Author
             of
             that
             Experiment
             contents
             himself
             to
             shew
             ,
             by
             the
             diminution
             of
             the
             weight
             of
             a
             Glass
             ,
             when
             the
             Air
             has
             been
             drawn
             out
             of
             it
             ,
             that
             the
             Air
             ,
             before
             t
             was
             drawn
             out
             ,
             was
             not
             devoid
             of
             Gravity
             ;
             the
             following
             Tryal
             does
             not
             onely
             perform
             the
             same
             thing
             ,
             and
             by
             a
             superadded
             circumstance
             confirm
             the
             Truth
             to
             be
             thereby
             prov'd
             ,
             but
             it
             indeavours
             also
             to
             shew
             the
             Proportion
             in
             Gravity
             betwixt
             the
             Air
             and
             Water
             .
             The
             Tryals
             themselves
             were
             registred
             among
             my
             Adversaria
             as
             follows
             .
          
           
             A
             small
             Receiver
             being
             exhausted
             of
             Air
             by
             the
             Engine
             ,
             and
             counterpois'd
             whilst
             it
             continued
             so
             ;
             the
             Stop-cock
             was
             turn'd
             ,
             and
             the
             Air
             readmitted
             ,
             which
             made
             it
             weigh
             36
             Grains
             more
             
             than
             it
             did
             before
             :
             and
             to
             prevent
             Jealousies
             ,
             we
             caus'd
             it
             to
             be
             applied
             the
             second
             time
             to
             the
             Engine
             ,
             by
             which
             the
             Air
             being
             emptied
             once
             more
             ,
             the
             Glass
             was
             put
             into
             the
             other
             Scale
             of
             the
             former
             Ballance
             ,
             and
             so
             counterpois'd
             ;
             and
             then
             the
             External
             Air
             being
             readmitted
             ,
             (
             which
             rush'd
             in
             as
             formerly
             with
             a
             whistling
             noise
             )
             ,
             there
             was
             found
             36
             Grains
             or
             better
             ,
             requisite
             to
             restore
             the
             Ballance
             to
             an
             Aequilibrium
             .
          
           
             We
             took
             a
             small
             Glass
             Receiver
             fitted
             with
             a
             Stopcock
             ,
             and
             having
             exhausted
             it
             of
             the
             Air
             ,
             and
             counterpois'd
             it
             ,
             and
             let
             in
             the
             outward
             Air
             ,
             we
             found
             the
             vveight
             of
             the
             Vessel
             to
             be
             increased
             by
             that
             admission
             36
             Grains
             .
             This
             done
             ,
             we
             took
             the
             Receiver
             ,
             after
             having
             well
             counterpois'd
             it
             ,
             out
             of
             the
             Scale
             ;
             and
             having
             apply'd
             it
             the
             second
             time
             to
             the
             Engine
             ,
             we
             once
             more
             withdrew
             the
             Air
             ,
             and
             then
             turning
             the
             Stop-cock
             to
             keep
             out
             the
             external
             Air
             ,
             vve
             took
             care
             that
             none
             of
             the
             Cement
             ,
             imploy'd
             to
             joyn
             it
             to
             the
             Engine
             ,
             should
             stick
             to
             it
             ,
             as
             we
             had
             diligently
             freed
             it
             from
             adherent
             Cement
             before
             we
             last
             apply'd
             it
             to
             the
             Engine
             .
             Then
             weighing
             it
             again
             ,
             we
             found
             it
             to
             weigh
             either
             35
             or
             36
             Grains
             (
             but
             rather
             the
             former
             )
             heavier
             than
             it
             did
             ,
             when
             t
             was
             last
             counterpois'd
             in
             the
             same
             Ballance
             .
             This
             being
             also
             done
             ,
             we
             immers'd
             the
             Stop-cock
             into
             a
             Bason
             of
             fair
             Water
             ,
             and
             let
             in
             the
             Liquor
             ,
             that
             we
             might
             find
             how
             much
             Water
             would
             succeed
             in
             place
             of
             the
             Air
             vve
             had
             drawn
             out
             .
             When
             no
             more
             vvater
             vvas
             impell'd
             in
             ,
             vve
             turned
             the
             Stop-cock
             once
             more
             ,
             to
             keep
             it
             from
             falling
             out
             ,
             and
             then
             weighing
             it
             in
             the
             same
             Scales
             ,
             (
             after
             we
             had
             wip'd
             the
             Stop-cock
             ,
             that
             no
             Water
             might
             stick
             to
             it
             on
             the
             outside
             ,
             )
             we
             found
             the
             water
             (
             without
             computing
             the
             vessel
             )
             to
             weigh
             47
             ounces
             ,
             3
             drachms
             ,
             and
             6
             Grains
             ,
             vvhich
             divided
             by
             35
             Grains
             ,
             (
             which
             I
             took
             to
             be
             the
             weight
             of
             the
             Air
             ,
             that
             vvas
             equal
             in
             Bulk
             to
             this
             vvater
             that
             succeeded
             it
             ,
             )
             the
             Quotient
             was
             (
             wanting
             a
             very
             litle
             )
             650
             Grains
             ,
             for
             the
             proportion
             of
             the
             vveight
             between
             Air
             and
             Water
             of
             the
             same
             bigness
             ,
             
               at
               the
               time
               when
               the
               Experiment
               was
               made
               :
            
             vvhich
             circumstance
             I
             therefore
             take
             notice
             of
             ,
             because
             the
             Atmosphere
             
             appear'd
             by
             the
             Baroscope
             (
             wherein
             the
             Mercury
             stood
             then
             at
             29
             inches
             and
             3
             /
             4
             )
             to
             be
             very
             heavy
             ;
             which
             made
             me
             the
             less
             wonder
             to
             find
             this
             proportion
             not
             so
             Great
             ,
             as
             at
             other
             times
             I
             had
             observed
             it
             to
             be
             between
             Water
             and
             Air
             in
             point
             of
             weight
             :
             though
             I
             suspected
             ,
             that
             because
             this
             odd
             Experiment
             cannot
             be
             nimbly
             dispatched
             ,
             some
             litle
             Air
             may
             have
             got
             in
             at
             the
             Stop-cock
             ,
             besides
             the
             Air
             that
             disclos'd
             it self
             in
             numerous
             bubbles
             in
             the
             vvater
             that
             vvas
             admitted
             ,
             vvhere
             though
             it
             lay
             in
             such
             small
             particles
             as
             not
             to
             be
             discerned
             before
             ;
             yet
             these
             particles
             ,
             by
             this
             opportunity
             to
             expand
             themselves
             ,
             extricated
             themselves
             from
             the
             vvater
             ,
             and
             by
             getting
             together
             might
             somewhat
             resist
             the
             Ingress
             of
             more
             ;
             vvhich
             is
             a
             difficulty
             ,
             vvhere
             to
             the
             measuring
             the
             proportion
             between
             VVater
             and
             Air
             in
             a
             heated
             Eoliple
             is
             liable
             .
             But
             the
             Stealing
             in
             of
             any
             Air
             ,
             before
             the
             vvater
             vvas
             let
             in
             ,
             is
             mentioned
             but
             as
             a
             Suspicion
             .
          
           
             Your
             Lordship
             may
             perhaps
             think
             it
             somewhat
             strange
             ,
             that
             I
             should
             present
             You
             Tryals
             ,
             whose
             Events
             do
             not
             so
             vvell
             agree
             together
             ,
             as
             perchance
             You
             expected
             .
             But
             this
             very
             Disagreement
             vvas
             one
             of
             the
             motives
             that
             induc'd
             me
             to
             acquaint
             You
             vvith
             them
             :
             for
             all
             those
             compris'd
             in
             these
             Experiments
             being
             made
             faithfully
             ,
             and
             not
             without
             (
             at
             the
             least
             )
             an
             ordinary
             diligence
             ,
             as
             they
             seem
             to
             make
             it
             probable
             ,
             that
             one
             may
             without
             any
             Great
             errour
             estimate
             the
             proportion
             of
             our
             English
             Air
             to
             VVater
             to
             be
             as
             (
             One
             )
             to
             some
             number
             betwixt
             600
             and
             1100
             ;
             so
             t
             is
             not
             to
             be
             expected
             ,
             that
             the
             Proportion
             ,
             vvhatever
             it
             be
             that
             should
             be
             pitch'd
             upon
             ,
             should
             be
             accurate
             and
             stable
             .
             For
             though
             Learned
             men
             seem
             to
             have
             hitherto
             taken
             it
             for
             granted
             ,
             that
             it
             may
             suffice
             once
             for
             all
             diligently
             to
             investigate
             the
             proportion
             betwixt
             those
             two
             Bodies
             ,
             yet
             ,
             not
             onely
             I
             am
             apt
             to
             believe
             that
             a
             Determinate
             quantity
             of
             Air
             (
             as
             a
             Pint
             or
             Quart
             )
             may
             be
             unequally
             heavy
             in
             distant
             Countreys
             ,
             and
             even
             in
             differing
             places
             of
             the
             same
             Countrey
             ;
             but
             what
             I
             have
             taken
             notice
             of
             in
             the
             17
             th
             of
             the
             printed
             Experiments
             ,
             and
             afterwards
             frequently
             observ'd
             of
             the
             Great
             inequalities
             of
             the
             vveight
             of
             the
             Atmosphere
             ,
             
             inclines
             me
             to
             think
             ,
             that
             in
             the
             self
             same
             place
             two
             Experiments
             may
             be
             made
             with
             the
             same
             Instruments
             ,
             and
             equal
             diligence
             ,
             and
             yet
             the
             weights
             of
             the
             Air
             may
             be
             found
             differing
             enough
             ;
             which
             may
             keep
             Your
             Lordship
             from
             much
             wondering
             ,
             that
             in
             the
             36
             th
             printed
             Experiment
             ,
             made
             when
             I
             had
             the
             variations
             of
             the
             Atmospheres
             Gravity
             in
             my
             Eye
             ,
             I
             found
             the
             Air
             to
             be
             less
             ponderous
             in
             reference
             to
             Water
             ,
             than
             in
             these
             later
             Tryals
             .
             But
             of
             this
             I
             hope
             I
             shall
             ,
             if
             God
             permit
             ,
             make
             further
             Tryals
             with
             the
             same
             vessels
             ,
             at
             times
             when
             I
             shall
             perceive
             by
             the
             Baroscope
             ,
             that
             the
             Gravity
             of
             the
             Atmosphere
             is
             very
             Great
             and
             very
             Small
             .
             And
             I
             wish
             the
             Curious
             would
             make
             the
             like
             Tryals
             in
             other
             Regions
             .
             I
             do
             not
             forget
             ,
             that
             not
             onely
             the
             School
             philosophers
             ,
             but
             most
             of
             the
             Moderns
             deny
             ,
             that
             Air
             hath
             any
             weight
             in
             Air
             ,
             no
             more
             than
             Water
             in
             Water
             ;
             but
             having
             a
             elsewhere
             declared
             and
             explained
             my
             sense
             about
             this
             received
             Opinion
             ,
             I
             shall
             not
             here
             spend
             any
             of
             the
             litle
             time
             I
             have
             remaining
             ,
             to
             justifie
             my
             Dissent
             ;
             for
             which
             Your
             Lordship
             may
             find
             sufficient
             Grounds
             in
             the
             newly
             related
             Experiments
             ,
             especially
             if
             You
             please
             to
             consider
             ,
             that
             though
             the
             Opinion
             I
             disallow
             have
             been
             chiefly
             and
             generally
             grounded
             upon
             some
             Arguments
             supposed
             to
             evince
             ,
             that
             vvater
             has
             no
             vveight
             in
             vvater
             ,
             I
             have
             b
             elsewhere
             shewn
             those
             Proofs
             not
             to
             be
             cogent
             ,
             and
             taught
             a
             Practical
             way
             of
             weighting
             vvater
             in
             vvater
             with
             a
             pair
             of
             ordinary
             Scales
             .
             c
          
        
         
           
             EXPERIMENT
             L.
             
          
           
             About
             the
             disjoyning
             of
             two
             Marbles
             (
             not
             otherwise
             to
             be
             pull'd
             asunder
             without
             a
             great
             weight
             )
             by
             withdrawing
             the
             pressure
             of
             the
             Air
             from
             them
             .
          
           
             IN
             our
             formerly
             publish'd
             Experiments
             about
             the
             Air
             *
             ,
             I
             did
             ,
             if
             I
             misremember
             not
             ,
             acquaint
             Your
             Lordship
             with
             an
             Attempt
             
             I
             had
             made
             to
             make
             a
             couple
             of
             coherent
             Marbles
             fall
             asunder
             ,
             by
             withdrawing
             the
             Air
             from
             them
             ;
             but
             though
             I
             then
             esteem'd
             that
             their
             Cohaesion
             depended
             upon
             the
             Pressure
             of
             the
             Air
             ,
             yet
             not
             being
             at
             that
             time
             furnish'd
             with
             all
             the
             accommodations
             requisite
             to
             make
             an
             Experiment
             not
             easie
             to
             be
             perform'd
             succeed
             ,
             I
             thought
             fit
             ,
             when
             I
             had
             afterwards
             opportunity
             ,
             to
             prosecute
             what
             I
             then
             began
             ,
             and
             add
             some
             circumstances
             that
             I
             could
             not
             then
             make
             Tryal
             of
             ;
             and
             yet
             whose
             success
             will
             not
             I
             presume
             be
             unwelcome
             ,
             since
             it
             supplies
             us
             with
             no
             less
             than
             matters
             of
             fact
             ;
             whence
             we
             may
             argue
             ,
             that
             this
             Experiment
             of
             coherent
             Marbles
             (
             which
             not
             onely
             the
             Aristotelian
             Plenists
             have
             of
             late
             much
             triumph'd
             in
             ,
             but
             which
             some
             recent
             Favourers
             of
             our
             Hypothesis
             have
             declar'd
             themselves
             to
             be
             troubled
             with
             )
             is
             not
             onely
             reconcileable
             to
             our
             Doctrine
             ,
             but
             capable
             of
             being
             made
             a
             confirmation
             of
             it
             ;
             notwithstanding
             what
             has
             lately
             been
             publish'd
             (
             upon
             the
             supposition
             of
             a
             case
             ,
             which
             at
             first
             Blush
             may
             seem
             somewhat
             of
             kin
             to
             our
             Experiment
             ,
             )
             by
             a
             very
             learned
             *
             Writer
             ,
             to
             whose
             objection
             against
             our
             Hypothesis
             ,
             though
             as
             well
             confidently
             as
             very
             civilly
             proposed
             ,
             an
             Answer
             may
             in
             due
             place
             ,
             if
             your
             Lordship
             desire
             it
             ,
             be
             return'd
             .
          
           
             We
             took
             two
             flat
             round
             Marbles
             ,
             each
             of
             them
             of
             two
             inches
             and
             about
             3
             quarters
             in
             Diameter
             ,
             and
             having
             put
             a
             litle
             Oyl
             between
             them
             to
             keep
             out
             the
             Air
             ,
             we
             hung
             at
             a
             Hook
             fastned
             to
             the
             Lowermost
             a
             Pound
             weight
             to
             surmount
             the
             Cohaesion
             ,
             which
             the
             tenacity
             of
             the
             Oyl
             and
             the
             imperfect
             Exhaustion
             of
             the
             Receiver
             might
             give
             them
             .
             Then
             having
             suspended
             them
             in
             the
             cavity
             of
             a
             Receiver
             ,
             at
             a
             stick
             that
             lay
             (
             Horizontally
             )
             a
             cross
             it
             ;
             when
             the
             Engine
             was
             fill'd
             ,
             and
             ready
             to
             work
             ,
             we
             shook
             it
             so
             strongly
             ,
             that
             those
             that
             were
             wont
             to
             manage
             it
             ,
             concluded
             ,
             it
             would
             not
             be
             near
             so
             much
             shaken
             by
             the
             Operation
             .
             Then
             beginning
             to
             pump
             out
             the
             Air
             ,
             we
             observ'd
             the
             Marbles
             to
             continue
             joyned
             till
             it
             was
             so
             far
             drawn
             out
             ,
             that
             we
             began
             to
             be
             diffident
             whether
             they
             would
             separate
             .
             But
             at
             the
             16
             th
             Suck
             ,
             
               upon
               the
               turning
               of
               the
               Stop-cock
               ,
            
             (
             which
             gave
             the
             Air
             a
             passage
             out
             of
             
             the
             Receiver
             into
             the
             Pump
             ,
             )
             the
             shaking
             of
             the
             Engine
             being
             almost
             ,
             if
             not
             quite
             ,
             over
             ,
             the
             Marbles
             spontaneously
             fell
             asunder
             ,
             wanting
             that
             Pressure
             of
             the
             Air
             ,
             that
             formerly
             had
             kept
             them
             together
             :
             which
             Event
             was
             the
             more
             considerable
             ,
             not
             onely
             because
             they
             hung
             parallel
             to
             the
             Horizon
             ,
             but
             adher'd
             so
             firmly
             together
             when
             they
             were
             put
             in
             ,
             that
             having
             try'd
             to
             pull
             them
             asunder
             ,
             and
             thereby
             observ'd
             how
             close
             they
             stuck
             together
             ,
             I
             foretold
             it
             would
             cost
             a
             good
             deal
             of
             pains
             so
             far
             to
             withdraw
             the
             Air
             ,
             as
             to
             make
             them
             separate
             :
             which
             Conjecture
             Your
             Lordship
             will
             the
             less
             wonder
             at
             ,
             if
             I
             adde
             ,
             that
             a
             weight
             of
             80
             and
             odd
             pounds
             ,
             fastned
             to
             the
             lowermost
             Marble
             ,
             may
             be
             drawn
             up
             together
             with
             the
             uppermost
             ,
             by
             vertue
             of
             the
             firmness
             of
             their
             Cohesion
             .
          
           
             NB.
             This
             is
             not
             the
             onely
             time
             that
             this
             Experiment
             succeeded
             with
             us
             .
             For
             sometimes
             ,
             when
             they
             were
             not
             so
             closely
             press'd
             together
             before
             they
             were
             put
             in
             ,
             the
             Disjunction
             was
             made
             at
             the
             8
             th
             Suck
             ,
             or
             sooner
             ,
             and
             we
             seem'd
             to
             our selves
             to
             observe
             ,
             that
             when
             we
             hung
             but
             half
             a
             pound
             weight
             to
             the
             lower
             Marble
             ,
             it
             requir'd
             a
             Greater
             exhaustion
             of
             the
             Receiver
             to
             separate
             them
             ,
             than
             when
             we
             hung
             the
             whole
             Pound
             .
          
           
             After
             ,
             having
             proceeded
             thus
             far
             with
             the
             Instruments
             we
             then
             had
             ,
             meeting
             with
             an
             Artificer
             that
             was
             not
             altogether
             unskilful
             ,
             we
             directed
             him
             to
             make
             (
             what
             we
             wanted
             before
             in
             that
             place
             )
             such
             a
             Brass-plate
             to
             serve
             for
             a
             Cover
             or
             Cap
             to
             the
             upper
             orifice
             of
             Receivers
             open
             at
             the
             top
             ,
             as
             we
             have
             divers
             times
             had
             occasion
             to
             mention
             already
             in
             giving
             accounts
             of
             some
             of
             the
             foregoing
             Tryals
             :
             by
             the
             help
             of
             which
             Contrivance
             we
             prosecuted
             the
             newly
             related
             Experiment
             much
             further
             than
             we
             could
             do
             before
             ,
             as
             may
             appear
             by
             the
             following
             account
             .
          
           
             We
             fasten'd
             to
             the
             lower
             most
             of
             the
             two
             Marbles
             a
             weight
             of
             a
             very
             few
             ounces
             ,
             (
             for
             I
             remember
             not
             the
             precise
             number
             ,
             )
             and
             having
             cemented
             the
             capp'd
             Receiver
             with
             the
             Marbles
             in
             it
             ,
             as
             before
             ,
             to
             the
             Pump
             ,
             we
             did
             by
             a
             string
             ,
             whereof
             one
             end
             was
             tied
             to
             the
             bottom
             of
             this
             Turning-key
             ,
             and
             the
             other
             to
             the
             uppermost
             
             Marble
             ,
             and
             which
             (
             string
             )
             past
             through
             the
             Crank
             or
             Hook
             belonging
             to
             the
             Brass-Cover
             ;
             we
             did
             ,
             I
             say
             ,
             by
             the
             help
             of
             this
             string
             ,
             and
             by
             turning
             round
             the
             Key
             ,
             draw
             up
             the
             superiour
             Marble
             ,
             and
             by
             reason
             of
             their
             coherence
             the
             lowermost
             also
             ,
             together
             with
             the
             weight
             that
             hung
             at
             it
             :
             by
             which
             means
             being
             sure
             ,
             that
             the
             two
             Marbles
             stuck
             close
             together
             ,
             we
             began
             to
             pump
             out
             the
             Air
             that
             kept
             them
             coherent
             ;
             and
             after
             a
             while
             ,
             the
             Air
             being
             pretty
             well
             withdrawn
             ,
             the
             Marbles
             fell
             asunder
             .
             But
             we
             having
             so
             order'd
             the
             matter
             ,
             that
             the
             lowermost
             could
             fall
             but
             a
             litle
             way
             beneath
             the
             other
             ,
             we
             were
             able
             by
             inclining
             and
             shaking
             the
             Engine
             to
             place
             them
             one
             upon
             another
             again
             ,
             and
             then
             letting
             in
             the
             Air
             somewhat
             hastily
             ,
             that
             by
             its
             Spring
             it
             might
             press
             them
             hard
             together
             ,
             we
             found
             the
             Expedient
             to
             succeed
             so
             well
             ,
             that
             we
             were
             not
             onely
             able
             by
             turning
             the
             abovementioned
             Cylindrical
             Key
             ,
             to
             make
             the
             uppermost
             Marble
             take
             up
             the
             other
             ,
             and
             the
             annexed
             weight
             ;
             but
             we
             were
             fain
             to
             make
             a
             much
             more
             laborious
             and
             diligent
             Exhaustion
             of
             the
             Air
             to
             procure
             the
             disjunction
             of
             the
             Marbles
             this
             second
             time
             ,
             than
             was
             necessary
             to
             do
             it
             at
             the
             first
             .
          
           
             And
             for
             further
             prevention
             of
             the
             Objections
             or
             Scruples
             that
             I
             foresaw
             some
             Prepossessions
             might
             suggest
             ,
             I
             thought
             fit
             to
             make
             this
             further
             Tryal
             ,
             that
             when
             the
             Marbles
             were
             thus
             asunder
             ,
             and
             the
             Receiver
             exhausted
             ,
             we
             did
             ,
             before
             we
             let
             in
             the
             Air
             ,
             make
             the
             Marbles
             fall
             upon
             one
             another
             as
             before
             ;
             but
             the
             litle
             and
             highly
             expanded
             Air
             that
             remained
             in
             the
             Receiver
             ,
             having
             not
             a
             Spring
             near
             strong
             enough
             to
             press
             them
             together
             ,
             by
             turning
             the
             Key
             we
             very
             easily
             rais'd
             the
             uppermost
             Marble
             alone
             ,
             without
             finding
             it
             to
             stick
             to
             the
             other
             as
             before
             .
             Whereupon
             we
             once
             more
             joyn'd
             the
             Marbles
             together
             ,
             and
             then
             letting
             in
             the
             external
             Air
             ,
             we
             found
             them
             afterwards
             to
             stick
             so
             close
             ,
             that
             I
             could
             not
             without
             inconvenience
             strain
             any
             further
             ,
             than
             I
             fruitlesly
             did
             ,
             to
             pull
             them
             fairly
             asunder
             ;
             and
             therefore
             gave
             them
             to
             one
             that
             was
             stronger
             than
             I
             ,
             to
             try
             ,
             whether
             he
             could
             do
             it
             ,
             which
             He
             also
             in
             vain
             attempted
             to
             perform
             .
          
           
           
             And
             now
             ,
             my
             Lord
             ,
             though
             I
             had
             thoughts
             of
             adding
             divers
             other
             Experiments
             to
             those
             I
             have
             hitherto
             entertained
             You
             with
             ;
             yet
             (
             upon
             a
             review
             )
             finding
             These
             to
             amount
             already
             to
             fifty
             ,
             I
             think
             it
             not
             amiss
             to
             make
             a
             Pause
             at
             so
             convenient
             a
             Number
             .
             And
             the
             rather
             ,
             because
             an
             odd
             Quartainary
             Distemper
             ,
             that
             I
             slighted
             so
             long
             ,
             as
             to
             give
             it
             time
             to
             take
             Root
             ,
             is
             now
             grown
             so
             troublesome
             ,
             that
             I
             fear
             it
             may
             have
             too
             much
             influence
             upon
             my
             Style
             ;
             which
             Apprehension
             obliges
             me
             as
             well
             to
             avoid
             abusing
             ,
             or
             distressing
             Your
             Lordship's
             Patience
             ,
             as
             to
             allow
             my self
             some
             seasonable
             Refreshment
             ,
             to
             reserve
             the
             mention
             of
             the
             design'd
             Additions
             till
             they
             can
             with
             less
             trouble
             to
             us
             both
             be
             presented
             You
             by
          
           
             
               My
               Dear
               Lord
            
             
               Your
               Lordship's
               most
               humble
               Servant
               ,
               and
               Affectionate
               Uncle
               ,
               ROBERT
               BOYLE
               .
            
             
               Oxford
               ,
               
                 March
                 the
                 24.
                 1667.
                 
              
            
          
        
      
       
         
         
           NOTES
           &c.
           About
           the
           ATMOSPHERES
           of
           
             Consistent
             Bodies
          
           (
           here
           below
           .
           )
        
         
           SHEWING
           ,
           That
           even
           HARD
           and
           SOLID
           BODIES
           (
           and
           some
           such
           as
           one
           would
           scarce
           suspect
           )
           are
           capable
           of
           emitting
           EFFLUVIA
           ,
           and
           so
           of
           having
           ATMOSPHERES
           .
        
         
           
           
           
             An
             Advertisement
             .
          
           
             HE
             that
             shall
             take
             the
             pains
             to
             peruse
             the
             following
             Paper
             ,
             will
             easily
             believe
             me
             ,
             when
             I
             tell
             him
             ,
             that
             t
             was
             not
             design'd
             to
             come
             abroad
             with
             the
             Experiments
             ,
             in
             whose
             company
             it
             now
             appears
             .
             But
             the
             Stationer
             earnestly
             representing
             that
             divers
             Experiments
             being
             reserved
             by
             me
             for
             another
             occasion
             ,
             the
             remaining
             ones
             alone
             would
             not
             give
             the
             Book
             a
             Thickness
             any
             thing
             proportionable
             to
             its
             Breadth
             ;
             I
             consented
             ,
             at
             his
             sollicitation
             ,
             to
             annexe
             to
             them
             the
             following
             Observations
             ,
             because
             of
             some
             affinity
             between
             the
             small
             Atmospheres
             of
             lesser
             Bodies
             ,
             and
             the
             great
             Atmosphere
             that
             surrounds
             the
             Terrestrial
             Globe
             ;
             in
             which
             the
             other
             ,
             that
             do
             at
             least
             help
             to
             compose
             it
             ,
             are
             lost
             and
             confounded
             ,
             as
             Brooks
             and
             Rivers
             are
             in
             the
             Ocean
             .
             And
             to
             save
             the
             Reader
             the
             pains
             of
             making
             Guesses
             to
             what
             kind
             of
             Writing
             the
             ensuing
             Discourse
             may
             belong
             ,
             I
             shall
             here
             intimate
             ,
             that
             t
             is
             dismembred
             from
             certain
             Papers
             about
             Occult
             Qualities
             in
             general
             ,
             which
             make
             part
             of
             the
             Notes
             I
             long
             since
             designed
             ,
             and
             also
             partly
             published
             ,
             about
             the
             
               Origine
               of
               Qualities
            
             ,
             of
             which
             Notes
             those
             that
             concern'd
             Effluviums
             ,
             being
             the
             most
             copious
             ,
             I
             referr'd
             them
             to
             four
             general
             Heads
             ;
             whereof
             the
             first
             onely
             is
             treated
             of
             in
             the
             following
             Discourse
             ,
             the
             others
             being
             withheld
             ,
             as
             having
             not
             affinity
             enough
             with
             the
             Atmosphere
             to
             accompany
             This
             ,
             whereon
             they
             have
             no
             such
             absolute
             Dependance
             ,
             but
             that
             they
             may
             well
             enough
             spare
             it
             .
             And
             I
             make
             the
             less
             Scruple
             to
             let
             it
             appear
             without
             them
             ,
             because
             the
             Inducements
             already
             mentioned
             are
             not
             a
             litle
             strengthned
             by
             this
             superadded
             Consideration
             ,
             That
             the
             following
             Notes
             may
             give
             light
             to
             several
             of
             the
             Observations
             I
             have
             
             made
             of
             some
             lesse
             heeded
             Phanomena
             of
             the
             Alterations
             of
             the
             Air
             ,
             in
             case
             they
             be
             allowed
             to
             enter
             into
             the
             Appendix
             to
             this
             Continuation
             .
          
        
         
           
           
             Of
             the
             Atmospheres
             of
             Consistent
             Bodies
             .
          
           
             THe
             School
             Philosophers
             ,
             and
             the
             Vulgar
             ,
             in
             considering
             the
             more
             abstruse
             Operations
             and
             Phaenomena
             of
             Nature
             ,
             are
             wont
             to
             run
             into
             Extremes
             ;
             which
             ,
             though
             opposite
             to
             one
             another
             ,
             do
             almost
             equally
             contribute
             to
             keep
             men
             ignorant
             of
             the
             true
             causes
             of
             those
             Effects
             they
             admire
             .
             For
             the
             Vulgar
             ,
             being
             accustomed
             to
             converse
             with
             sensible
             objects
             ,
             and
             to
             conceive
             grosly
             of
             things
             ,
             cannot
             easily
             imagine
             any
             other
             Agents
             in
             Nature
             ,
             then
             those
             that
             they
             can
             see
             ,
             if
             not
             also
             touch
             ,
             and
             handle
             ;
             and
             as
             soon
             as
             they
             meet
             with
             an
             Effect
             ,
             that
             they
             cannot
             ascribe
             to
             some
             palpable
             ,
             or
             at
             least
             sensible
             Efficient
             ,
             they
             are
             ,
             and
             stick
             not
             to
             confess
             themselves
             utterly
             at
             a
             loss
             .
             And
             though
             the
             vulgar
             of
             Philosophers
             will
             not
             acknowledg
             themselves
             to
             be
             pos'd
             by
             the
             same
             phaenomena
             with
             the
             vulgar
             of
             Men
             ,
             yet
             in
             effect
             they
             are
             so
             .
             But
             the
             School-philosophers
             on
             the
             contrary
             ,
             do
             not
             onely
             refuse
             to
             acquiesce
             in
             sensible
             Agents
             ,
             but
             to
             solve
             the
             more
             Mysterious
             Phaenomena
             of
             Nature
             ,
             nay
             and
             most
             of
             the
             Familiar
             ones
             too
             ,
             they
             scruple
             not
             to
             run
             too
             far
             to
             the
             other
             side
             ,
             and
             have
             their
             recourse
             to
             Agents
             that
             are
             not
             onely
             invisible
             ,
             but
             inconceivable
             ,
             at
             least
             to
             men
             that
             cannot
             admit
             any
             save
             Rational
             and
             consistent
             Nations
             :
             they
             ascribe
             all
             abstruse
             Effects
             to
             certain
             substantial
             Forms
             ,
             which
             however
             they
             call
             Material
             ,
             because
             of
             their
             dependence
             on
             Matter
             ,
             they
             give
             such
             Descriptions
             to
             ,
             as
             belong
             but
             to
             Spiritual
             Beings
             :
             as
             if
             all
             the
             abstruser
             Effects
             of
             Nature
             ,
             if
             they
             be
             not
             perform'd
             by
             visible
             Bodies
             ,
             must
             be
             so
             by
             immaterial
             substances
             :
             whereas
             betwixt
             visible
             bodies
             and
             Spiritual
             Beings
             there
             is
             a
             middle
             sort
             of
             Agents
             ,
             invisible
             Corpuscles
             ;
             by
             which
             a
             Great
             part
             of
             the
             difficulter
             phaenomena
             of
             Nature
             are
             produc'd
             ,
             and
             by
             which
             may
             intelligibly
             be
             
             explicated
             those
             Phaenomena
             ,
             which
             't
             were
             absurd
             to
             refer
             to
             the
             former
             ,
             and
             precarious
             to
             attribute
             to
             the
             latter
             .
             Now
             for
             methods
             sake
             I
             will
             refer
             the
             Notes
             ,
             that
             occur
             to
             me
             about
             Effluviums
             ,
             to
             four
             Heads
             ;
             whereof
             the
             first
             is
             mentioned
             in
             the
             Title
             of
             this
             Paper
             ,
             and
             each
             of
             the
             other
             three
             shall
             be
             successively
             treated
             of
             in
             as
             many
             distinct
             ones
             .
          
           
             That
             Fluid
             Bodies
             ,
             as
             Liquors
             ,
             and
             such
             as
             are
             manifestly
             either
             moist
             ,
             or
             soft
             ,
             should
             easily
             send
             forth
             Emanations
             ,
             will
             I
             presume
             be
             granted
             without
             much
             difficulty
             ;
             especially
             considering
             the
             sensible
             Evaporation
             that
             is
             obvious
             to
             be
             observ'd
             in
             Water
             ,
             Wine
             ,
             Urine
             ,
             &c.
             and
             the
             loose
             contexture
             of
             parts
             that
             is
             suppos'd
             to
             be
             requisite
             to
             constitute
             soft
             Bodies
             ,
             (
             as
             Flowers
             ,
             Balsomes
             ,
             and
             the
             like
             :
             )
             but
             that
             even
             Hard
             and
             ponderous
             Bodies
             ,
             notwithstanding
             the
             Solidity
             and
             strict
             cohesion
             of
             their
             component
             parts
             ,
             should
             likewise
             emit
             Steams
             ,
             will
             to
             many
             appear
             improbable
             enough
             to
             need
             to
             be
             solemnly
             prov'd
             .
          
           
             Whether
             you
             admit
             the
             Atomical
             Hypothesis
             ,
             or
             prefer
             the
             Cartesian
             ,
             I
             think
             it
             may
             be
             probably
             deduc'd
             from
             either
             ,
             that
             very
             many
             of
             the
             Bodies
             we
             are
             treating
             of
             ,
             may
             be
             suppos'd
             exhaleable
             as
             to
             their
             very
             minute
             parts
             .
             For
             according
             to
             the
             Doctrine
             of
             
               Lucippus
               ,
               Democritus
            
             ,
             and
             Epicurus
             ,
             each
             indivisible
             particle
             of
             Matter
             hath
             essentially
             either
             a
             constant
             actual
             motion
             ,
             or
             an
             unlooseable
             endeavour
             after
             it
             ,
             so
             that
             though
             it
             may
             be
             so
             complicated
             in
             some
             Concretions
             ,
             with
             other
             minute
             parts
             ,
             as
             to
             have
             its
             Avolation
             hindred
             for
             a
             while
             ;
             yet
             it
             can
             scarce
             otherwise
             be
             ,
             but
             by
             this
             incessant
             Indeavour
             of
             all
             the
             Atomes
             to
             get
             loose
             ,
             some
             of
             them
             should
             from
             time
             to
             time
             be
             able
             to
             extricate
             themselves
             ,
             and
             fly
             away
             .
             And
             though
             the
             Cartesians
             do
             not
             allow
             Matter
             to
             have
             any
             innate
             motion
             ,
             yet
             according
             to
             them
             both
             Vegetables
             ,
             Animals
             ,
             and
             Minerals
             ,
             consist
             of
             litle
             parts
             so
             contexed
             ,
             that
             their
             Pores
             give
             passage
             to
             a
             Celestial
             Matter
             ;
             so
             that
             this
             Matter
             continually
             streaming
             through
             them
             ,
             may
             well
             be
             presum'd
             to
             shake
             the
             Corpuscles
             that
             compose
             them
             :
             by
             which
             continued
             concussion
             now
             some
             Particles
             ,
             and
             then
             others
             ,
             will
             
             be
             thrown
             and
             carried
             off
             into
             the
             Air
             ,
             or
             other
             contiguous
             Body
             ,
             fitted
             to
             receive
             them
             .
             But
             though
             by
             these
             ,
             and
             perhaps
             other
             considerations
             ,
             I
             might
             indeavour
             to
             shew
             
               à
               priori
            
             ,
             as
             they
             speak
             ,
             that
             t
             is
             probable
             Consistent
             Bodies
             themselves
             are
             exhaleable
             ,
             yet
             I
             think
             it
             may
             be
             as
             satisfactory
             ,
             and
             more
             useful
             ,
             to
             prove
             it
             
               à
               posteriori
            
             ,
             by
             particular
             Experiments
             ,
             and
             other
             Examples
             .
          
           
             That
             then
             a
             dry
             and
             consistent
             form
             does
             not
             necessarily
             infer
             ,
             in
             the
             Bodies
             that
             are
             endowed
             with
             it
             ,
             an
             indisposition
             to
             send
             forth
             Steams
             ,
             which
             are
             as
             it
             were
             litle
             Colonies
             of
             Particles
             ,
             is
             evident
             ,
             not
             onely
             in
             the
             leaves
             of
             Damask
             Roses
             ,
             whether
             fresh
             or
             dried
             ;
             as
             also
             in
             Wormwood
             ,
             Mint
             ,
             Rue
             ,
             &c
             :
             but
             in
             Ambergreece
             ,
             Musk
             ,
             Storax
             ,
             Cinamon
             ,
             Nutmegs
             ,
             and
             other
             odoriferous
             and
             spicy
             bodies
             .
             But
             more
             eminent
             Examples
             to
             our
             present
             purpose
             may
             be
             afforded
             us
             by
             Camphire
             ,
             and
             volatile
             Salts
             ,
             such
             as
             are
             Chymically
             obtain'd
             from
             Harts-horn
             ,
             Blood
             ,
             &c.
             for
             these
             are
             so
             fugitive
             ,
             that
             sometimes
             I
             have
             had
             a
             considerable
             Lump
             of
             volatile
             Salt
             (
             either
             of
             fermented
             Urine
             ,
             or
             of
             Harts-horn
             )
             fly
             away
             by
             litle
             and
             litle
             out
             of
             a
             Glass
             ,
             that
             had
             been
             carefully
             stopt
             with
             a
             Cork
             ,
             without
             leaving
             so
             much
             as
             a
             Grain
             of
             Salt
             behind
             it
             .
             And
             as
             for
             Camphire
             ,
             though
             by
             its
             being
             uneasie
             to
             be
             powder'd
             ,
             it
             seems
             to
             have
             something
             of
             Toughness
             or
             Tenacity
             in
             it
             ;
             yet
             I
             remember
             ,
             that
             having
             for
             tryals
             sake
             counterpois'd
             it
             in
             nice
             Scales
             ,
             even
             a
             small
             lump
             of
             it
             would
             in
             a
             few
             hours
             suffer
             a
             visible
             loss
             of
             its
             weight
             ,
             by
             the
             avolation
             of
             strongly
             sented
             Corpuscles
             ,
             and
             this
             ,
             though
             the
             Experiment
             were
             made
             both
             in
             a
             North
             Window
             ,
             and
             in
             Winter
             .
          
           
             But
             I
             expect
             you
             should
             require
             Instances
             of
             the
             Effluviums
             of
             Bodies
             of
             a
             close
             or
             solid
             Texture
             ;
             wherefore
             I
             proceed
             to
             take
             notice
             ,
             that
             Amber
             ,
             Hard
             wax
             ,
             and
             many
             other
             Electrical
             bodies
             do
             ,
             when
             they
             are
             rubb'd
             ,
             emit
             Effluviums
             .
             For
             though
             I
             will
             not
             now
             meddle
             with
             the
             several
             Opinions
             about
             the
             cause
             and
             manner
             of
             Electrical
             Attraction
             ,
             yet
             besides
             that
             almost
             all
             the
             Modern
             Naturalists
             ,
             that
             aim
             at
             explicating
             things
             intelligibly
             ,
             ascribe
             the
             Attraction
             we
             are
             speaking
             of
             to
             Corporeal
             effluxes
             ;
             
             and
             besides
             that
             I
             shall
             ere
             long
             have
             occasion
             to
             shew
             you
             ,
             that
             there
             is
             no
             need
             to
             admit
             with
             Cartesius
             ,
             That
             because
             some
             Electrical
             bodies
             are
             very
             close
             and
             fixt
             ,
             what
             they
             emit
             upon
             rubbing
             is
             not
             part
             of
             their
             own
             Substance
             ,
             but
             somewhat
             that
             was
             harbour'd
             in
             their
             Pores
             :
             besides
             these
             things
             ,
             I
             say
             ,
             I
             have
             found
             that
             many
             Electrical
             bodies
             may
             by
             the
             very
             Nostrils
             be
             discovered
             ,
             when
             they
             are
             well
             rubb'd
             ,
             to
             part
             with
             store
             of
             Corpuscles
             ,
             as
             I
             have
             particularly
             ,
             but
             not
             without
             attention
             ,
             been
             able
             to
             observe
             in
             Amber
             ,
             Rosin
             ,
             Brimstone
             ,
             &c.
             
          
           
             I
             know
             not
             whether
             it
             will
             be
             worth
             while
             to
             take
             notice
             of
             the
             great
             Evaporation
             I
             have
             observ'd
             ,
             even
             in
             Winter
             ,
             of
             Fruits
             ,
             as
             Apples
             ,
             and
             of
             Bodies
             that
             seem
             to
             be
             better
             cover'd
             ,
             as
             Eggs
             ,
             which
             notwithstanding
             the
             closeness
             of
             their
             Shels
             ,
             did
             daily
             grow
             manifestly
             lighter
             and
             lighter
             ;
             as
             I
             observ'd
             in
             them
             ,
             and
             divers
             other
             bodies
             ,
             that
             I
             kept
             long
             in
             Scales
             ,
             and
             noted
             their
             Decrements
             of
             weight
             :
             but
             perhaps
             you
             will
             be
             pleas'd
             to
             hear
             ,
             that
             having
             a
             mind
             to
             shew
             how
             considerable
             an
             Evaporation
             is
             made
             from
             Wood
             ,
             I
             caus'd
             a
             thin
             Cup
             ,
             capable
             of
             holding
             about
             a
             Pint
             ,
             or
             more
             ,
             to
             be
             Turn'd
             of
             a
             Wood
             ,
             that
             was
             chosen
             by
             the
             Turner
             as
             solid
             and
             dry
             enough
             ,
             though
             it
             were
             not
             of
             the
             closest
             sort
             of
             Woods
             ,
             such
             as
             are
             
               Lignum
               vitae
            
             ,
             and
             Box.
             And
             as
             I
             caus'd
             the
             shape
             of
             a
             Cup
             to
             be
             given
             it
             ,
             that
             it
             might
             have
             a
             greater
             Superficies
             expos'd
             to
             the
             Air
             ,
             and
             consequently
             might
             be
             the
             fitter
             to
             emit
             store
             of
             Steams
             into
             it
             ;
             so
             the
             Success
             did
             not
             onely
             answer
             my
             Expectation
             ,
             but
             exceed
             it
             :
             for
             though
             the
             Tryal
             were
             made
             some
             time
             in
             Winter
             ,
             there
             was
             so
             quick
             and
             plentiful
             an
             Evaporation
             made
             from
             the
             Cup
             ,
             that
             I
             found
             it
             no
             easie
             matter
             to
             counterpoise
             it
             ;
             for
             whilst
             Grains
             were
             putting
             into
             the
             opposite
             Scale
             ,
             to
             bring
             the
             tender
             Ballance
             to
             an
             Aequilibrium
             ,
             the
             copious
             avolation
             of
             invisible
             Steams
             from
             the
             Wood
             (
             which
             had
             so
             much
             of
             Superficies
             contiguous
             to
             the
             Air
             )
             would
             make
             the
             Scale
             that
             held
             it
             sensibly
             too
             light
             .
             And
             I
             remember
             ,
             that
             for
             further
             satisfaction
             ,
             being
             afterwards
             in
             a
             City
             where
             there
             were
             both
             good
             Materials
             and
             workmen
             ,
             I
             order'd
             to
             be
             made
             a
             Boule
             ,
             about
             
             the
             same
             bigness
             with
             the
             former
             ,
             of
             well
             season'd
             wood
             ,
             which
             being
             suspended
             in
             the
             Chamber
             I
             lay
             in
             ,
             (
             which
             circumstance
             I
             therefore
             mention
             ,
             because
             the
             Weather
             and
             a
             litle
             Physick
             I
             had
             taken
             obliged
             me
             to
             keep
             a
             fire
             there
             ,
             )
             it
             quickly
             began
             manifestly
             to
             loose
             of
             its
             weight
             ;
             and
             though
             the
             whole
             Cup
             wanted
             near
             two
             Drams
             of
             2
             Ounces
             ,
             yet
             in
             12
             hours
             ,
             viz.
             from
             10
             a
             clock
             in
             the
             morning
             to
             the
             same
             hour
             at
             night
             ;
             it
             lost
             about
             40
             Grains
             ,
             (
             for
             t
             was
             above
             39
             :
             )
             but
             of
             such
             Experiments
             ,
             and
             the
             Cautions
             belonging
             to
             them
             ,
             I
             may
             elsewhere
             speak
             farther
             .
          
           
             It
             were
             not
             difficult
             for
             me
             to
             multiply
             Instances
             of
             the
             continual
             Emanation
             of
             Streams
             from
             Vegetable
             and
             Animal
             Substances
             ;
             but
             I
             am
             not
             willing
             to
             enlarge
             my self
             upon
             this
             Subject
             ,
             because
             I
             consider
             that
             there
             are
             other
             Bodies
             which
             seem
             so
             much
             more
             indispos'd
             to
             part
             with
             Effluviums
             ,
             that
             a
             few
             instances
             given
             in
             such
             ,
             may
             evince
             what
             I
             would
             prove
             ,
             much
             more
             then
             a
             multitude
             produc'd
             in
             other
             bodies
             .
             And
             since
             I
             consider
             that
             those
             Substances
             are
             the
             most
             unlikely
             to
             afford
             Effluvia
             ,
             that
             are
             either
             very
             cold
             ,
             or
             very
             ponderous
             ,
             or
             very
             solid
             and
             hard
             ,
             or
             very
             fixt
             ;
             if
             I
             can
             shew
             you
             that
             neither
             of
             these
             Qualifications
             can
             keep
             a
             Body
             from
             emitting
             Steams
             ,
             I
             hope
             I
             shall
             have
             made
             it
             probable
             ,
             that
             there
             is
             no
             sort
             of
             Bodies
             here
             below
             that
             may
             not
             be
             thought
             capable
             of
             affording
             the
             Corporeal
             Emanations
             we
             speak
             of
             .
          
           
             And
             first
             I
             remember
             ,
             that
             I
             have
             not
             onely
             taken
             Eggs
             ,
             and
             in
             a
             very
             sharp
             Winter
             found
             them
             ,
             notwithstanding
             the
             coldness
             of
             the
             Air
             where
             I
             kept
             them
             ,
             to
             grow
             sensibly
             lighter
             ,
             in
             a
             faithful
             pair
             of
             Scales
             ,
             in
             not
             very
             many
             hours
             ;
             but
             because
             Ice
             is
             thought
             the
             coldest
             visible
             Body
             we
             know
             ,
             I
             thought
             fit
             to
             shew
             that
             even
             this
             Body
             will
             loose
             by
             Evaporation
             ;
             for
             having
             counterpois'd
             a
             convenient
             quantity
             of
             Ice
             in
             a
             good
             Ballance
             ,
             and
             forthwith
             expos'd
             it
             therein
             to
             the
             cold
             Air
             of
             a
             Frosty
             night
             ,
             that
             the
             Evaporations
             should
             be
             from
             Ice
             not
             from
             Water
             ,
             I
             found
             the
             next
             morning
             ,
             that
             though
             the
             Scale
             wherein
             the
             Ice
             were
             put
             was
             dry
             ,
             which
             argued
             as
             well
             as
             the
             coldness
             of
             the
             Weather
             
             that
             the
             expos'd
             Concretion
             had
             not
             thaw'd
             ;
             yet
             I
             found
             its
             weight
             to
             be
             considerably
             diminished
             ,
             and
             this
             Experiment
             I
             succesfully
             made
             in
             more
             than
             one
             Winter
             ,
             and
             in
             more
             than
             one
             place
             .
             And
             t
             is
             now
             but
             a
             few
             dayes
             since
             ,
             exposing
             not
             long
             before
             midnight
             ,
             lesse
             than
             two
             ounces
             of
             Ice
             in
             a
             good
             Ballance
             to
             a
             sharply
             freezing
             Air
             ,
             I
             sent
             for
             it
             before
             I
             was
             up
             in
             the
             morning
             ,
             and
             though
             by
             the
             dryness
             of
             the
             Scales
             the
             Ice
             that
             was
             in
             one
             of
             them
             appear'd
             not
             to
             have
             thaw'd
             ,
             yet
             it
             had
             lost
             about
             ten
             Grains
             of
             its
             former
             weight
             ;
             so
             that
             here
             ,
             the
             Evaporation
             was
             made
             in
             spite
             of
             a
             double
             Cold
             ,
             of
             the
             Ice
             ,
             and
             of
             the
             Air.
             
          
           
             I
             should
             now
             proceed
             to
             the
             mention
             of
             ponderous
             and
             solid
             Bodies
             ,
             but
             before
             I
             do
             so
             ,
             it
             may
             be
             expedient
             to
             give
             you
             notice
             ,
             that
             ,
             to
             make
             the
             Proof
             of
             what
             I
             have
             propos'd
             more
             satisfactory
             ,
             and
             more
             applicable
             to
             our
             future
             purposes
             ,
             I
             shall
             forbear
             to
             give
             you
             any
             Examples
             of
             the
             exhalations
             of
             Bodies
             ,
             where
             so
             potent
             an
             Agent
             as
             the
             Fire
             is
             made
             to
             intervene
             .
          
           
             But
             though
             I
             purposely
             forbear
             to
             insist
             on
             such
             Examples
             ,
             yet
             it
             may
             not
             be
             amiss
             to
             intimate
             ,
             that
             in
             explicating
             some
             occult
             Qualities
             ,
             even
             such
             Exhalations
             as
             are
             produc'd
             by
             the
             help
             of
             the
             Fire
             may
             be
             fit
             to
             be
             taken
             into
             consideration
             ,
             as
             we
             may
             hereafter
             have
             occasion
             to
             shew
             .
             And
             therefore
             we
             may
             observe
             in
             general
             ,
             that
             the
             Fire
             is
             able
             to
             put
             the
             parts
             of
             Bodies
             into
             so
             vehement
             a
             motion
             ,
             that
             except
             Gold
             ,
             Glass
             ,
             and
             a
             very
             few
             more
             ,
             there
             are
             not
             any
             Bodies
             so
             fixt
             and
             solid
             ,
             that
             t
             is
             not
             thought
             capable
             to
             dissipate
             either
             totally
             ,
             or
             in
             part
             .
             T
             is
             known
             to
             those
             that
             deal
             in
             the
             fusion
             of
             Metals
             ,
             that
             not
             onely
             Lead
             and
             Tin
             ,
             but
             much
             harder
             Bodies
             will
             emit
             copious
             and
             hurtful
             Steams
             .
             And
             there
             are
             some
             kinds
             of
             that
             Iron
             ,
             which
             our
             Smiths
             call
             Cold
             share
             iron
             ,
             about
             whose
             smell
             whilst
             it
             was
             red
             hot
             ,
             when
             I
             made
             inquiry
             ,
             the
             ingeniousest
             Smith
             I
             had
             then
             met
             with
             told
             me
             ,
             that
             he
             had
             found
             it
             several
             times
             to
             be
             so
             strong
             ,
             and
             rank
             ,
             that
             he
             could
             scarce
             indure
             to
             work
             with
             his
             Hammer
             those
             parcels
             of
             Metal
             whence
             it
             proceeded
             .
             And
             even
             without
             being
             brought
             to
             fusion
             ,
             not
             onely
             Brass
             ,
             and
             Copper
             will
             ,
             being
             
             well
             heated
             ,
             become
             strongly
             sented
             ,
             but
             Iron
             will
             be
             so
             too
             ,
             as
             is
             evident
             by
             the
             unpleasing
             smell
             of
             many
             Iron-Stowes
             .
             And
             on
             this
             occasion
             I
             might
             not
             impertinently
             adde
             here
             a
             Tryal
             we
             made
             to
             observe
             ,
             whether
             the
             Steams
             of
             Iron
             may
             not
             be
             made
             ,
             though
             not
             immediately
             visible
             ,
             yet
             perceptible
             to
             the
             Eye
             it self
             ,
             though
             the
             Metal
             had
             not
             a
             Red
             ,
             much
             less
             a
             White
             heat
             .
             But
             having
             elsewhere
             related
             it
             at
             large
             ,
             in
             a
             Discourse
             You
             may
             command
             a
             sight
             of
             ,
             I
             shall
             rather
             refer
             You
             to
             it
             ,
             than
             loose
             the
             time
             't
             would
             take
             up
             to
             transcribe
             it
             .
          
           
             These
             things
             premis'd
             ,
             I
             proceed
             now
             to
             the
             mention
             of
             ponderous
             Bodies
             ;
             and
             concerning
             them
             ,
             to
             represent
             ,
             that
             if
             You
             will
             admit
             what
             almost
             all
             the
             Corpuscularians
             assert
             ,
             and
             divers
             of
             the
             Peripateticks
             do
             not
             now
             think
             fit
             to
             deny
             ,
             that
             the
             Magnetical
             operations
             are
             perform'd
             by
             Particles
             issuing
             forth
             of
             the
             body
             of
             the
             Loadstone
             ,
             or
             other
             Magnetical
             Agent
             :
             I
             shall
             not
             need
             to
             go
             far
             for
             an
             Instance
             to
             our
             present
             purpose
             ,
             since
             I
             have
             Hydrostatically
             found
             ,
             that
             some
             Loadstones
             (
             for
             I
             have
             found
             those
             Minerals
             very
             differing
             in
             Gravity
             )
             are
             so
             ponderous
             ,
             as
             to
             exceed
             double
             the
             weight
             of
             Flints
             ,
             or
             other
             Stones
             of
             the
             same
             bulk
             .
          
           
             But
             not
             to
             insist
             on
             Loadstones
             ,
             Stone-cutters
             will
             inform
             You
             ,
             (
             as
             they
             did
             me
             ,
             )
             that
             black
             Marble
             ,
             and
             some
             other
             solid
             and
             heavy
             stones
             will
             ,
             upon
             the
             attrition
             they
             are
             expos'd
             to
             ,
             when
             the
             Workmen
             are
             polishing
             them
             ,
             (
             especially
             without
             water
             ,
             )
             emit
             ,
             and
             that
             without
             the
             help
             of
             external
             heat
             ,
             a
             very
             sensible
             smell
             ,
             which
             I
             found
             to
             be
             much
             more
             strong
             and
             offensive
             when
             ,
             to
             make
             it
             so
             ,
             I
             had
             the
             curiosity
             to
             cause
             a
             piece
             of
             solid
             black
             Marble
             to
             have
             divers
             fragments
             struck
             off
             from
             it
             with
             a
             Chizel
             and
             a
             Hammer
             :
             for
             the
             stroaks
             succeeding
             one
             another
             fast
             enough
             to
             make
             a
             great
             concussion
             of
             the
             parts
             of
             the
             black
             Marble
             ,
             (
             for
             in
             white
             ,
             which
             is
             not
             so
             solid
             ,
             the
             Tryal
             will
             not
             succeed
             well
             ,
             )
             there
             quickly
             follow'd
             as
             I
             expected
             a
             rank
             and
             unpleasant
             smell
             ;
             and
             you
             will
             grant
             me
             I
             know
             ,
             that
             Odours
             are
             not
             diffus'd
             without
             corporeal
             Emanations
             .
             I
             remember
             also
             ,
             that
             having
             procur'd
             some
             of
             those
             acuminated
             and
             almost
             Conical
             
             stones
             ,
             that
             pass
             among
             the
             vulgar
             for
             Thunder-stones
             ,
             by
             rubbing
             them
             a
             litle
             one
             against
             the
             other
             ,
             I
             could
             easily
             according
             to
             my
             expectation
             excite
             a
             strong
             Sulphureous
             stink
             .
             I
             have
             also
             tried
             upon
             a
             certain
             Mineral
             Mass
             ,
             that
             was
             ponderous
             almost
             as
             a
             Metal
             ,
             but
             to
             Me
             it
             seem'd
             rather
             an
             unusual
             kind
             of
             Marchasite
             ,
             that
             I
             could
             in
             a
             trice
             without
             external
             heat
             make
             it
             emit
             more
             strongly
             sented
             Exhalations
             ,
             than
             I
             could
             contentedly
             endure
             :
             to
             which
             I
             shall
             adde
             this
             Example
             more
             ,
             that
             having
             once
             made
             a
             Chemical
             mixture
             of
             a
             Metalline
             body
             ,
             and
             coagulated
             Mercury
             ,
             which
             you
             will
             believe
             could
             not
             but
             be
             ponderous
             ,
             though
             this
             Mixture
             had
             already
             endur'd
             as
             violent
             a
             fire
             as
             was
             necessary
             to
             bring
             it
             to
             Fusion
             ,
             in
             order
             to
             cast
             it
             into
             Rings
             ;
             yet
             it
             was
             so
             dispos'd
             to
             part
             with
             corporeal
             Effluxes
             ,
             that
             a
             very
             ingenious
             Person
             that
             practis'd
             Physick
             ,
             and
             was
             there
             when
             I
             made
             it
             ,
             earnestly
             begg'd
             a
             little
             of
             it
             of
             me
             for
             some
             Patients
             troubled
             with
             distempers
             in
             the
             Eyes
             ,
             and
             other
             parts
             remote
             enough
             from
             the
             hand
             ;
             which
             he
             affirm'd
             himself
             to
             have
             very
             happily
             cured
             ,
             by
             making
             the
             Patient
             wear
             a
             Ring
             of
             this
             odde
             Mixture
             ,
             or
             wearing
             a
             litle
             of
             it
             as
             an
             Appensum
             near
             the
             disaffected
             part
             .
             If
             you
             make
             a
             
               vitrum
               Saturni
            
             with
             a
             good
             quantity
             of
             Minium
             in
             reference
             to
             the
             Sand
             or
             Chrystal
             ,
             which
             it
             helps
             to
             bring
             to
             Fusion
             ,
             you
             shall
             have
             a
             Glass
             exceeding
             ponderous
             ,
             and
             yet
             not
             devoid
             of
             Electricity
             :
             And
             I
             remember
             ,
             that
             having
             sometimes
             caus'd
             Brass
             it self
             to
             be
             Turn'd
             like
             Wood
             ,
             that
             I
             might
             try
             ,
             whether
             so
             Great
             (
             though
             invisible
             )
             a
             Concussion
             of
             all
             the
             parts
             would
             not
             throw
             off
             some
             Steams
             that
             might
             be
             smell'd
             ,
             I
             was
             not
             reduc'd
             to
             foregoe
             my
             Expectation
             ;
             but
             yet
             because
             it
             was
             not
             fully
             answer'd
             ,
             and
             because
             also
             there
             is
             great
             difference
             of
             Brass
             upon
             the
             score
             of
             the
             
               Lapis
               Calaminaris
            
             ,
             whereof
             together
             with
             Copper
             t
             is
             made
             ,
             I
             enquired
             of
             the
             Workman
             ,
             who
             us'd
             to
             turn
             great
             quantities
             of
             Brass
             ,
             whether
             he
             did
             not
             often
             after
             find
             it
             more
             strong
             ;
             and
             he
             inform'd
             me
             that
             he
             did
             ,
             the
             smell
             being
             sometimes
             so
             strong
             ,
             as
             to
             be
             offensive
             to
             Strangers
             ,
             that
             came
             to
             his
             Shop
             ,
             and
             were
             not
             us'd
             to
             it
             .
          
           
           
             I
             proceed
             now
             to
             the
             Effluviums
             of
             solid
             and
             hard
             Bodies
             ,
             of
             which
             ,
             if
             most
             of
             our
             Corpuscularian
             Philosophers
             ,
             and
             divers
             others
             be
             not
             much
             mistaken
             ,
             I
             may
             be
             allow'd
             to
             give
             instances
             in
             all
             Electrical
             Bodies
             ,
             which
             ,
             as
             I
             have
             already
             noted
             ,
             must
             according
             to
             their
             Doctrine
             be
             acknowledged
             to
             operate
             by
             substantial
             Emanations
             .
             Now
             among
             Electrical
             Bodies
             I
             have
             observ'd
             divers
             ,
             that
             are
             of
             so
             close
             a
             Texture
             ,
             that
             
               Aqua
               fortis
            
             its
             self
             ,
             nor
             spirit
             of
             Salt
             will
             work
             upon
             them
             ,
             and
             to
             be
             so
             hard
             ,
             that
             some
             of
             them
             will
             strike
             fire
             like
             Flints
             :
             Of
             the
             former
             sort
             I
             have
             found
             divers
             Gems
             (
             which
             I
             nam'd
             in
             my
             Notes
             about
             Electricity
             ,
             )
             and
             even
             the
             Cornelian
             it self
             ,
             which
             I
             found
             to
             attract
             Hairs
             ,
             though
             it
             be
             thought
             to
             be
             of
             a
             much
             slighter
             Texture
             than
             precious
             Stones
             ,
             did
             yet
             resist
             
               Aqua
               fortis
            
             ,
             as
             I
             tried
             in
             a
             large
             Ring
             ,
             (
             brought
             out
             of
             the
             East-Indies
             ,
             )
             which
             I
             purposely
             broke
             ,
             and
             reduced
             some
             part
             of
             it
             to
             powder
             ,
             that
             I
             might
             make
             these
             and
             some
             other
             Tryals
             with
             it
             .
             Rock
             Chrystal
             also
             ,
             though
             it
             have
             a
             very
             manifest
             attractive
             virtue
             (
             as
             they
             call
             it
             ,
             )
             I
             have
             yet
             found
             it
             so
             hard
             ,
             as
             to
             strike
             fire
             rather
             better
             than
             worse
             than
             ordinary
             Flints
             .
             And
             to
             shew
             that
             no
             hardness
             of
             a
             Body
             is
             inconsistent
             with
             its
             being
             Electrical
             ,
             I
             shall
             adde
             ,
             that
             though
             Diamonds
             be
             confest
             to
             be
             the
             hardest
             Bodies
             that
             are
             yet
             known
             in
             the
             world
             ,
             yet
             frequent
             Experience
             has
             assur'd
             me
             ,
             that
             even
             These
             ,
             whether
             raw
             or
             polish'd
             ,
             are
             very
             manifestly
             (
             and
             sometimes
             vigorously
             enough
             )
             Electrical
             .
          
           
             And
             to
             let
             you
             see
             ,
             that
             I
             need
             not
             to
             have
             recourse
             to
             this
             kind
             of
             Bodies
             ,
             to
             prove
             ,
             that
             very
             solid
             ones
             are
             capable
             of
             Effluvia
             ;
             I
             will
             ,
             to
             what
             I
             have
             formerly
             noted
             about
             the
             Odour
             of
             black
             Marble
             ,
             subjoin
             two
             or
             three
             Examples
             of
             the
             like
             nature
             .
          
           
             The
             first
             shall
             be
             taken
             from
             a
             sort
             of
             Concretions
             very
             well
             known
             in
             divers
             parts
             of
             Italy
             by
             the
             name
             of
             Cugoli
             ,
             because
             of
             the
             great
             use
             that
             is
             made
             of
             it
             by
             the
             Glass-men
             .
             These
             Concretions
             you
             will
             easily
             believe
             are
             very
             hard
             ,
             as
             other
             Minerals
             of
             that
             sort
             are
             wont
             to
             be
             ;
             and
             yet
             being
             invited
             by
             my
             Conjectures
             
             about
             the
             Atmospheres
             of
             Bodies
             ,
             to
             try
             them
             by
             rubbing
             them
             one
             against
             the
             other
             ,
             I
             found
             as
             I
             expected
             ,
             that
             they
             afforded
             not
             onely
             a
             perceptible
             ,
             but
             a
             very
             strong
             smell
             ,
             (
             which
             was
             far
             from
             that
             of
             a
             Perfume
             .
             )
          
           
             And
             this
             brings
             into
             my
             mind
             ,
             that
             having
             met
             with
             some
             Stones
             cut
             out
             of
             Humane
             bladders
             ,
             whose
             Texture
             was
             so
             close
             ,
             that
             I
             could
             not
             with
             Corrosive
             Menstruums
             make
             any
             sensible
             Solution
             of
             one
             whereon
             I
             made
             my
             Tryal
             ;
             though
             to
             facilitate
             the
             Liquors
             operation
             ,
             part
             of
             it
             were
             reduc'd
             to
             fine
             Powder
             ,
             yet
             by
             a
             litle
             rubbing
             of
             one
             of
             these
             so
             closely
             contexed
             Stones
             ,
             it
             would
             presently
             afford
             a
             rank
             smell
             ,
             very
             like
             the
             stink
             of
             stale
             Urine
             .
          
           
             I
             remember
             I
             have
             caus'd
             Iron
             to
             be
             turn'd
             with
             a
             Lath
             ,
             to
             examine
             whether
             by
             the
             internal
             commotion
             ,
             that
             would
             by
             that
             operation
             be
             produc'd
             in
             the
             corpuscles
             of
             the
             Metal
             ,
             even
             that
             solid
             as
             well
             as
             ponderous
             Bodie
             would
             not
             become
             capable
             of
             being
             smell'd
             ;
             and
             though
             by
             reason
             of
             the
             nature
             of
             that
             parcel
             of
             iron
             whereon
             we
             made
             our
             Tryal
             ,
             or
             some
             accidental
             disposition
             ,
             which
             was
             at
             that
             time
             (
             being
             Winter
             )
             in
             my
             organs
             of
             Smelling
             ,
             the
             Odour
             seem'd
             to
             me
             but
             very
             faint
             ;
             yet
             upon
             the
             enquiry
             I
             made
             of
             the
             Artificers
             ,
             whether
             in
             Turning
             greater
             pieces
             of
             iron
             they
             did
             not
             find
             the
             smell
             stronger
             ?
             they
             told
             me
             ,
             that
             they
             often
             found
             it
             very
             strong
             ,
             and
             sometimes
             more
             so
             than
             they
             desired
             .
          
           
             And
             this
             brings
             into
             my
             mind
             ,
             what
             I
             have
             carefully
             observ'd
             in
             Grinding
             of
             iron
             ;
             for
             there
             are
             many
             Grindstones
             so
             qualify'd
             ,
             that
             in
             case
             iron
             instruments
             be
             held
             upon
             the
             Stone
             ,
             whilst
             it
             is
             nimbly
             turn'd
             under
             it
             ,
             though
             the
             water
             that
             is
             wont
             to
             be
             us'd
             on
             such
             occasions
             stifles
             (
             if
             I
             may
             so
             speak
             )
             the
             Smell
             ,
             and
             keeps
             it
             from
             being
             commonly
             taken
             notice
             of
             ;
             yet
             if
             you
             purposely
             cause
             (
             as
             I
             remember
             I
             have
             done
             )
             the
             use
             of
             Water
             to
             be
             forborn
             ,
             your
             Success
             will
             not
             be
             like
             mine
             ,
             if
             you
             do
             not
             find
             that
             store
             of
             foetid
             Exhalations
             will
             be
             produc'd
             .
             And
             though
             it
             be
             not
             always
             so
             easie
             to
             discern
             by
             the
             smell
             ,
             from
             which
             of
             the
             
             two
             Bodies
             they
             issue
             ,
             or
             whether
             they
             proceed
             from
             both
             ;
             yet
             it
             seems
             probable
             enough
             ,
             that
             some
             of
             the
             Steams
             come
             from
             the
             iron
             ,
             and
             t
             is
             more
             than
             probable
             that
             if
             they
             proceed
             not
             from
             that
             Metal
             ,
             they
             must
             from
             a
             Body
             that
             is
             so
             hard
             as
             to
             be
             able
             to
             make
             impressions
             in
             a
             trice
             upon
             Iron
             and
             Steel
             themselves
             .
          
           
             The
             last
             Example
             I
             shall
             name
             under
             this
             head
             ,
             is
             furnish'd
             me
             by
             Marchasites
             ,
             some
             of
             which
             would
             after
             a
             short
             concussion
             without
             external
             heat
             be
             made
             to
             exhale
             for
             a
             pretty
             while
             together
             a
             strong
             Sulphureous
             odour
             ,
             and
             yet
             were
             so
             hard
             ,
             that
             when
             struck
             with
             a
             Steel-hammer
             ,
             (
             which
             would
             not
             easily
             break
             them
             )
             they
             afforded
             us
             such
             a
             number
             of
             Sparks
             ,
             as
             appear'd
             strange
             enough
             .
             And
             t
             is
             known
             ,
             that
             t
             is
             from
             their
             disposition
             to
             strike
             fire
             ,
             (
             which
             yet
             I
             dare
             not
             attribute
             to
             all
             sorts
             of
             Marchasites
             ,
             )
             that
             this
             kind
             of
             Mineral
             is
             ,
             by
             a
             name
             frequently
             to
             be
             met
             with
             in
             Writers
             ,
             call'd
             Pyrites
             .
             And
             in
             this
             Example
             we
             may
             take
             notice
             ,
             that
             a
             Body
             ,
             capable
             of
             being
             the
             source
             of
             corporeal
             Emanations
             ,
             may
             be
             at
             once
             both
             very
             solid
             and
             very
             ponderous
             .
          
           
             It
             remains
             now
             that
             I
             manifest
             ,
             that
             even
             the
             Fixedness
             of
             Bodies
             is
             not
             incompatible
             with
             their
             disposition
             to
             emit
             Effluviums
             .
          
           
             I
             might
             alleadg
             on
             this
             occasion
             ,
             that
             the
             Regulus
             of
             Antimony
             ,
             and
             also
             its
             Glass
             ,
             though
             they
             must
             have
             endur'd
             Fusion
             to
             attain
             their
             respective
             Forms
             ;
             yet
             they
             will
             without
             heat
             communicate
             to
             Liquors
             Antimonial
             Expirations
             ,
             with
             which
             those
             Liquors
             being
             impregnated
             become
             Emetick
             and
             Purgative
             .
             I
             might
             also
             adde
             ,
             that
             divers
             Electrical
             Bodies
             are
             very
             fixt
             in
             the
             fire
             ,
             and
             particularly
             that
             Chrystal
             ,
             as
             we
             have
             more
             than
             once
             tried
             ,
             will
             endure
             several
             Ignitions
             and
             Extinctions
             in
             water
             ,
             without
             being
             truly
             Calcin'd
             ,
             being
             indeed
             but
             crackt
             into
             a
             great
             multitude
             of
             litle
             parts
             ;
             but
             because
             the
             above
             named
             Antimonial
             bodies
             will
             after
             a
             while
             fly
             away
             in
             a
             strong
             fire
             ,
             and
             because
             the
             Effluviums
             of
             Chrystal
             are
             not
             so
             sensible
             as
             those
             which
             can
             immediately
             affect
             our
             Eyes
             or
             Nostrils
             ,
             I
             will
             here
             subjoyn
             one
             instance
             ,
             such
             as
             I
             hope
             will
             make
             it
             needless
             for
             me
             to
             adde
             any
             
             more
             ,
             it
             being
             of
             a
             Body
             which
             must
             have
             sustain'd
             an
             exceeding
             vehement
             fire
             ,
             and
             is
             look'd
             upon
             by
             most
             of
             the
             Chymists
             as
             more
             understroyable
             then
             Gold
             it self
             ,
             and
             that
             is
             Glass
             ,
             which
             is
             able
             as
             you
             know
             to
             endure
             so
             great
             a
             brunt
             of
             the
             fire
             ,
             that
             you
             did
             not
             perhaps
             imagine
             I
             should
             of
             all
             Bodies
             name
             it
             on
             this
             occasion
             .
             But
             my
             conjectures
             about
             the
             Atmospheres
             of
             Bodies
             leading
             me
             to
             think
             ,
             that
             Glass
             it self
             might
             afford
             me
             a
             confirmation
             of
             them
             ;
             I
             quickly
             found
             ,
             that
             by
             rubbing
             a
             very
             litle
             while
             two
             solid
             pieces
             of
             it
             (
             not
             ,
             as
             I
             remember
             ,
             of
             the
             finer
             sort
             )
             one
             against
             the
             other
             ,
             they
             would
             not
             onely
             yield
             a
             sensible
             Odour
             ,
             but
             sometimes
             so
             strong
             an
             one
             ,
             as
             to
             be
             offensive
             .
             By
             which
             you
             will
             easily
             perceive
             why
             I
             told
             you
             above
             ,
             that
             I
             did
             not
             acquiesce
             in
             the
             Cartesian
             Argument
             against
             Electrical
             Bodies
             performing
             their
             operations
             by
             Emanations
             of
             their
             own
             substance
             ,
             drawn
             from
             hence
             ,
             that
             Glass
             does
             attract
             light
             Bodies
             ,
             (
             as
             indeed
             it
             does
             ,
             though
             but
             weakly
             ,
             )
             and
             yet
             is
             too
             fixt
             to
             emit
             Effluviums
             ,
             the
             contrary
             of
             which
             Supposition
             the
             lately
             mentioned
             Experiment
             (
             and
             by
             us
             often
             repeated
             )
             does
             sufficiently
             evince
             .
          
           
             From
             what
             other
             solid
             Bodies
             ,
             and
             that
             will
             endure
             the
             fire
             ,
             I
             have
             ,
             or
             have
             not
             been
             able
             to
             obtain
             such
             odorous
             Steams
             ,
             it
             is
             not
             necessary
             to
             declare
             in
             this
             place
             ,
             but
             may
             perhaps
             be
             done
             in
             another
             .
          
           
             You
             may
             I
             presume
             have
             taken
             notice
             ,
             that
             according
             to
             what
             I
             intimated
             a
             while
             agoe
             ,
             I
             have
             forborn
             in
             the
             precedent
             Examples
             to
             mention
             those
             Effluvia
             of
             solid
             Bodies
             ,
             that
             need
             the
             action
             of
             the
             Fire
             to
             be
             obtain'd
             .
             But
             since
             the
             Sun
             is
             the
             grand
             Agent
             of
             Nature
             in
             the
             Planetary
             world
             ,
             and
             since
             during
             the
             Summer
             ,
             and
             especially
             at
             Noon
             ,
             and
             in
             Southern
             Climates
             ,
             his
             Heat
             makes
             many
             bodies
             have
             litle
             Atmospheres
             ,
             that
             we
             cannot
             so
             well
             discern
             that
             they
             have
             constantly
             ;
             I
             see
             not
             why
             I
             may
             not
             be
             allow'd
             to
             ascribe
             Atmospheres
             to
             such
             Bodies
             ,
             as
             I
             have
             observ'd
             to
             have
             them
             when
             the
             Sun
             shines
             upon
             them
             ,
             and
             also
             to
             think
             that
             the
             like
             may
             be
             attributed
             at
             least
             sometimes
             to
             such
             other
             
             Bodies
             ,
             as
             will
             do
             the
             things
             usually
             perform'd
             by
             Effluviums
             ,
             when
             yet
             they
             are
             excited
             but
             by
             an
             external
             heat
             ,
             which
             exceeds
             not
             that
             of
             the
             hot
             Sun.
             
          
           
             Of
             these
             two
             sorts
             of
             Bodies
             I
             shall
             for
             brevities
             sake
             name
             but
             two
             or
             three
             Examples
             ,
             and
             then
             hasten
             to
             a
             Conclusion
             .
          
           
             The
             first
             of
             these
             I
             must
             make
             bold
             to
             borrow
             from
             my
             Observations
             about
             Electricity
             ,
             among
             which
             this
             is
             one
             ,
             that
             to
             shew
             that
             the
             particular
             and
             usual
             manner
             of
             exciting
             such
             Bodies
             ,
             namely
             by
             rubbing
             them
             ,
             is
             not
             alwayes
             necessary
             ;
             I
             took
             a
             large
             piece
             of
             good
             Amber
             ,
             and
             having
             in
             a
             Summer
             morning
             ,
             whilst
             the
             Air
             was
             yet
             fresh
             ,
             tried
             that
             it
             would
             not
             without
             being
             excited
             attract
             a
             light
             Body
             I
             had
             expos'd
             to
             it
             ;
             I
             remov'd
             it
             into
             the
             Suns
             beams
             ,
             till
             they
             had
             made
             it
             moderately
             hot
             ,
             and
             then
             I
             found
             according
             to
             my
             expectation
             that
             it
             had
             acquir'd
             an
             Attractive
             virtue
             ,
             &
             that
             not
             onely
             in
             one
             particular
             place
             ,
             as
             is
             usually
             observ'd
             when
             t
             is
             excited
             by
             rubbing
             ,
             but
             in
             divers
             and
             distant
             places
             at
             once
             ;
             at
             any
             of
             which
             it
             would
             draw
             to
             it
             the
             light
             body
             plac'd
             within
             a
             convenient
             distance
             from
             it
             :
             so
             that
             even
             in
             this
             Climate
             of
             ours
             a
             solid
             Body
             may
             quickly
             acquire
             an
             Atmosphere
             by
             the
             presence
             of
             the
             Sun
             ,
             and
             that
             long
             before
             the
             warmest
             part
             of
             the
             day
             .
          
           
             The
             next
             instance
             you
             will
             perchance
             think
             somewhat
             strange
             ,
             it
             being
             that
             when
             for
             want
             of
             an
             opportunity
             to
             make
             the
             like
             Trial
             in
             the
             warm
             Sun
             ,
             I
             took
             a
             litle
             but
             thick
             vessel
             made
             of
             Glass
             ,
             and
             held
             it
             near
             the
             fire
             till
             it
             had
             got
             a
             convenient
             degree
             of
             heat
             ,
             (
             which
             was
             not
             very
             great
             ,
             though
             it
             exceeded
             that
             which
             I
             had
             given
             the
             Amber
             ,
             )
             I
             found
             as
             I
             had
             imagin'd
             that
             the
             heat
             of
             fire
             had
             made
             even
             this
             Body
             attractive
             ,
             as
             that
             of
             the
             Sun
             had
             made
             the
             other
             .
          
           
             What
             degree
             of
             heat
             I
             have
             observ'd
             to
             be
             either
             necessary
             ,
             or
             the
             most
             convenient
             to
             excite
             Electrical
             bodies
             according
             to
             their
             different
             natures
             ,
             (
             for
             the
             same
             degree
             will
             not
             indifferently
             serve
             for
             them
             all
             ,
             )
             this
             is
             not
             the
             properest
             place
             to
             declare
             ,
             and
             it
             will
             be
             more
             to
             our
             present
             purpose
             to
             make
             some
             short
             reflection
             on
             what
             has
             been
             hitherto
             delivered
             .
          
           
           
             It
             seems
             then
             probably
             deduceable
             from
             the
             foregoing
             Experiments
             and
             Observations
             ,
             that
             a
             very
             great
             number
             if
             not
             the
             greatest
             part
             even
             of
             Consistent
             bodies
             ,
             whether
             Animal
             ,
             Vegetable
             ,
             or
             Mineral
             ,
             may
             emit
             Effluviums
             ,
             and
             that
             even
             those
             that
             are
             solid
             may
             (
             at
             least
             sometimes
             )
             have
             their
             litle
             Atmospheres
             ,
             though
             the
             neighbouring
             Solids
             will
             often
             keep
             the
             Evaporations
             from
             being
             every
             way
             ambient
             in
             reference
             to
             the
             Bodies
             they
             issue
             from
             .
          
           
             For
             as
             the
             instances
             hitherto
             alleadg'd
             (
             which
             are
             not
             all
             that
             I
             could
             have
             nam'd
             )
             do
             plainly
             shew
             that
             divers
             Bodies
             (
             and
             some
             that
             have
             not
             been
             thought
             very
             likely
             )
             are
             such
             as
             we
             speak
             of
             ,
             so
             several
             things
             induce
             me
             to
             believe
             ,
             that
             there
             may
             be
             many
             more
             of
             the
             like
             nature
             .
          
           
             For
             first
             ,
             very
             few
             if
             any
             have
             (
             that
             I
             know
             of
             )
             had
             the
             curiosity
             to
             make
             use
             of
             nice
             Scales
             ,
             (
             which
             such
             Tryals
             require
             ,
             )
             to
             examine
             the
             Expirations
             of
             inanimate
             bodies
             ,
             which
             if
             they
             shall
             hereafter
             do
             ,
             I
             make
             litle
             doubt
             but
             they
             will
             light
             on
             many
             things
             ,
             that
             will
             confirm
             what
             we
             have
             been
             proposing
             ,
             by
             their
             finding
             that
             some
             Bodies
             ,
             which
             are
             not
             yet
             known
             to
             yield
             Exhalations
             ,
             do
             afford
             them
             ,
             and
             that
             many
             others
             do
             part
             with
             far
             more
             copious
             ones
             than
             is
             imagin'd
             .
             For
             one
             would
             not
             easily
             have
             thought
             ,
             that
             so
             extremely
             cold
             a
             Body
             as
             a
             solid
             piece
             of
             Ice
             should
             make
             a
             plentiful
             Evaporation
             of
             its
             self
             in
             the
             cold
             Air
             of
             a
             freezing
             night
             ;
             or
             that
             a
             piece
             of
             Wood
             ,
             that
             had
             long
             lain
             in
             the
             house
             ,
             and
             was
             light
             enough
             to
             be
             conveniently
             hung
             for
             a
             long
             time
             at
             a
             Ballance
             ,
             that
             would
             loose
             its
             Aequilibrium
             with
             (
             as
             I
             remember
             )
             half
             a
             quarter
             of
             a
             Grain
             ,
             should
             in
             less
             than
             a
             minute
             of
             an
             hour
             ,
             send
             forth
             steams
             enough
             to
             make
             the
             Scales
             manifestly
             turn
             ,
             and
             that
             in
             Winter
             .
          
           
             But
             supposing
             (
             which
             is
             my
             second
             Consideration
             )
             that
             Tryals
             were
             made
             with
             good
             instruments
             for
             weighing
             ,
             though
             it
             will
             follow
             ,
             that
             in
             case
             the
             exposed
             body
             grow
             lighter
             ,
             something
             exhales
             from
             it
             ;
             yet
             it
             will
             not
             follow
             ,
             that
             if
             no
             diminution
             of
             weight
             be
             discover'd
             by
             the
             instrument
             ,
             nothing
             that
             is
             corporeal
             
             recedes
             from
             it
             .
             I
             will
             not
             urge
             that
             t
             is
             affirm'd
             ,
             not
             onely
             by
             the
             generality
             of
             our
             Chymists
             ,
             but
             by
             learned
             modern
             Physitians
             ,
             that
             when
             either
             Glass
             of
             Antimony
             ,
             or
             
               Crocus
               metallorum
            
             impregnate
             Wine
             with
             Vomative
             and
             Purgative
             Particles
             ,
             they
             do
             it
             without
             any
             decrement
             of
             their
             weight
             ;
             because
             the
             Scales
             in
             Apothecaries
             Shops
             ,
             and
             the
             litle
             accurateness
             wont
             to
             be
             imployed
             in
             weighing
             things
             ,
             by
             those
             that
             are
             not
             vers'd
             in
             Statical
             affairs
             ,
             make
             me
             (
             though
             not
             deny
             the
             Tradition
             which
             may
             perchance
             be
             true
             ,
             yet
             )
             unwilling
             to
             build
             upon
             observations
             ,
             which
             to
             be
             relyed
             on
             are
             to
             be
             very
             nicely
             made
             ;
             and
             therefore
             I
             shall
             rather
             take
             notice
             ,
             that
             though
             the
             Loadstone
             be
             concluded
             to
             have
             constantly
             about
             it
             a
             great
             multitude
             of
             Magnetical
             Effluvia
             ,
             (
             which
             may
             be
             call'd
             its
             Atmosphere
             ,
             )
             yet
             it
             has
             not
             been
             observed
             to
             loose
             any
             thing
             of
             its
             Weight
             by
             the
             recess
             of
             so
             many
             Corpuscles
             .
             But
             because
             if
             the
             Cartesian
             Hypothesis
             about
             Magnetisms
             be
             admitted
             ,
             the
             Argument
             drawn
             from
             this
             instance
             will
             not
             be
             so
             strong
             as
             it
             seems
             ,
             and
             as
             it
             otherwise
             would
             be
             :
             I
             shall
             add
             a
             more
             unexceptionable
             Example
             ,
             for
             I
             know
             you
             will
             grant
             me
             that
             Odours
             are
             not
             diffus'd
             to
             a
             distance
             without
             Corporeal
             Emanations
             from
             the
             Odorous
             body
             :
             and
             yet
             ,
             though
             good
             Amber-Greece
             be
             ,
             even
             without
             being
             excited
             by
             external
             heat
             ,
             constantly
             surrounded
             by
             a
             large
             Atmosphere
             ,
             you
             will
             in
             one
             of
             the
             following
             Discourses
             find
             cause
             to
             admire
             how
             inconsiderable
             the
             wast
             of
             it
             is
             .
          
           
             If
             it
             be
             said
             ,
             that
             in
             Tract
             of
             time
             a
             Decrement
             of
             weight
             may
             appear
             in
             Bodies
             ,
             that
             in
             a
             few
             hours
             or
             dayes
             discovers
             not
             any
             ;
             the
             Objection
             ,
             if
             granted
             ,
             overthrows
             not
             our
             Doctrine
             ,
             it
             being
             sufficient
             to
             establish
             what
             we
             have
             been
             saying
             ,
             if
             we
             have
             evinc'd
             that
             the
             Effluvia
             of
             some
             Bodies
             may
             be
             subtle
             enough
             not
             to
             make
             the
             Body
             by
             their
             avolation
             appear
             lighter
             in
             Statical
             Trials
             ,
             that
             are
             not
             extraordinarily
             (
             and
             as
             it
             were
             obstinately
             )
             protracted
             .
             And
             this
             very
             Objection
             puts
             me
             in
             mind
             to
             adde
             ,
             that
             for
             ought
             we
             know
             the
             Decrement
             of
             Bodies
             in
             Statical
             Experiments
             long
             continued
             ,
             may
             be
             somewhat
             Greater
             than
             even
             nice
             
             Scales
             discover
             to
             us
             ;
             for
             how
             are
             we
             sure
             that
             the
             weights
             themselves
             ,
             which
             are
             commonly
             made
             of
             Brass
             ,
             (
             a
             Metal
             very
             unfixt
             ,
             )
             may
             not
             in
             Tract
             of
             time
             suffer
             a
             litle
             Diminution
             of
             their
             Weight
             ,
             as
             well
             as
             the
             Bodies
             counterpois'd
             by
             them
             :
             and
             no
             man
             has
             I
             think
             yet
             tryed
             whether
             Glass
             ,
             and
             even
             Gold
             may
             not
             in
             tract
             of
             time
             loose
             of
             their
             Weight
             ,
             which
             in
             case
             they
             should
             do
             ,
             it
             would
             not
             be
             easily
             discover'd
             ,
             unless
             we
             had
             Bodies
             that
             were
             perfectly
             fixt
             ,
             by
             comparison
             to
             which
             we
             might
             be
             better
             assisted
             ,
             than
             by
             comparing
             them
             with
             Brass
             weights
             ,
             or
             the
             like
             ,
             which
             being
             themselves
             less
             fixt
             ,
             will
             lose
             more
             than
             Gold
             and
             Glass
             .
          
           
             My
             third
             and
             last
             consideration
             is
             ,
             that
             there
             may
             be
             divers
             other
             wayes
             ,
             besides
             those
             furnish'd
             us
             by
             Staticks
             ,
             of
             discovering
             the
             Effluvia
             of
             solid
             Bodies
             ,
             and
             consequently
             of
             shewing
             ,
             that
             t
             is
             not
             safe
             to
             conclude
             ,
             that
             because
             their
             Operation
             is
             not
             constant
             or
             manifest
             ,
             such
             Bodies
             do
             never
             emit
             any
             Effluvia
             at
             all
             ,
             and
             so
             are
             uncapable
             to
             work
             by
             their
             intervention
             on
             any
             other
             Body
             ,
             though
             never
             so
             well
             dispos'd
             to
             receive
             their
             Action
             .
             And
             this
             I
             the
             rather
             desire
             that
             you
             would
             take
             notice
             of
             ,
             because
             my
             chief
             (
             though
             not
             onely
             )
             design
             in
             these
             Notes
             is
             (
             you
             know
             )
             to
             illustrate
             the
             Doctrine
             of
             
               occult
               Qualities
            
             ;
             and
             it
             may
             conduce
             to
             explicate
             several
             of
             them
             ,
             to
             know
             that
             some
             particular
             Bodies
             emit
             Effluvia
             ,
             though
             perhaps
             they
             do
             it
             not
             constantly
             ,
             and
             uniformly
             ;
             and
             though
             perchance
             too
             ,
             they
             do
             not
             appear
             to
             emit
             any
             at
             all
             ,
             if
             they
             be
             examin'd
             after
             the
             same
             manner
             with
             other
             exhaleable
             Bodies
             ,
             but
             onely
             may
             be
             made
             to
             emit
             them
             by
             some
             peculiar
             way
             of
             handling
             them
             ,
             or
             appear
             to
             have
             emitted
             them
             by
             some
             determinate
             operation
             on
             some
             other
             single
             Body
             ,
             or
             at
             most
             small
             number
             of
             Bodies
             .
          
           
             Perchance
             you
             did
             not
             think
             ,
             till
             you
             read
             what
             I
             lately
             told
             you
             about
             Glass
             ,
             that
             from
             a
             Body
             that
             had
             endured
             so
             violent
             a
             fire
             ,
             there
             could
             ,
             by
             so
             sleight
             a
             way
             as
             rubbing
             a
             litle
             while
             one
             piece
             against
             another
             ,
             be
             obtain'd
             such
             steams
             ,
             as
             may
             not
             onely
             affect
             but
             offend
             the
             Nostrils
             .
             Nor
             should
             we
             easily
             believe
             ,
             if
             Experience
             
             did
             not
             assure
             us
             of
             it
             ,
             that
             a
             Diamond
             ,
             that
             is
             justly
             reputed
             the
             hardest
             known
             Body
             in
             the
             World
             ,
             should
             by
             a
             litle
             rubbing
             be
             made
             to
             part
             with
             Electrical
             Effluvia
             .
             Nay
             ,
             (
             that
             I
             may
             give
             some
             kind
             of
             confirmation
             to
             that
             part
             of
             the
             last
             Paragraph
             that
             seems
             most
             to
             need
             it
             ,
             )
             I
             shall
             adde
             ,
             that
             I
             once
             had
             a
             Diamond
             not
             much
             bigger
             than
             a
             large
             Pen
             ,
             which
             had
             never
             been
             polish'd
             or
             cut
             ,
             whose
             Electrical
             virtue
             was
             sometimes
             so
             easily
             excited
             ,
             that
             if
             I
             did
             but
             pass
             my
             fingers
             over
             it
             to
             wipe
             it
             ,
             the
             virtue
             would
             disclose
             it self
             ;
             and
             if
             as
             soon
             as
             I
             had
             taken
             it
             out
             of
             my
             Pocket
             ,
             I
             applied
             a
             hair
             to
             it
             ,
             though
             I
             touch'd
             not
             the
             Stone
             with
             my
             fingers
             ,
             that
             I
             might
             be
             sure
             not
             to
             rub
             it
             ,
             that
             Hair
             would
             be
             attracted
             at
             some
             distance
             ,
             and
             many
             times
             one
             after
             an
             other
             ,
             especially
             by
             one
             of
             the
             sides
             of
             the
             Stone
             ,
             (
             whose
             surface
             was
             made
             up
             of
             several
             almost
             triangular
             Planes
             ,
             )
             and
             though
             this
             excitation
             of
             the
             Diamond
             seemed
             to
             proceed
             onely
             from
             the
             warmth
             that
             it
             had
             acquir'd
             in
             my
             Pocket
             ,
             yet
             I
             did
             not
             find
             that
             That
             warmth
             ,
             though
             it
             seem'd
             not
             to
             be
             alter'd
             ,
             had
             alwaies
             the
             same
             effect
             on
             it
             ,
             though
             the
             wiping
             it
             with
             my
             finger
             fail'd
             not
             (
             that
             I
             remember
             )
             to
             excite
             it
             .
             Something
             like
             this
             uncertainty
             I
             always
             observ'd
             in
             another
             Diamond
             of
             mine
             ,
             that
             was
             much
             nobler
             than
             the
             first
             ,
             and
             very
             well
             polished
             ,
             and
             in
             a
             small
             Ruby
             ,
             that
             I
             have
             yet
             by
             me
             ,
             which
             would
             sometimes
             be
             considerably
             Electrical
             without
             being
             rubb'd
             ,
             when
             I
             but
             wore
             the
             Ring
             it
             belong'd
             to
             on
             my
             litle
             finger
             ;
             and
             sometimes
             again
             it
             seem'd
             to
             have
             lost
             that
             virtue
             (
             of
             operating
             without
             being
             excited
             by
             friction
             ,
             )
             and
             that
             sometimes
             within
             a
             few
             minutes
             ,
             without
             my
             knowing
             whence
             so
             quick
             a
             change
             should
             proceed
             .
             But
             I
             must
             insist
             no
             longer
             on
             such
             particulars
             ,
             of
             which
             I
             elsewhere
             say
             something
             ;
             and
             therefore
             I
             prceed
             to
             take
             notice
             ,
             that
             we
             should
             scarce
             have
             dream'd
             ,
             that
             when
             a
             Partridg
             ,
             or
             a
             hunted
             Deer
             has
             casually
             set
             a
             foot
             upon
             the
             ground
             ,
             that
             part
             where
             the
             Footstep
             hath
             been
             (
             though
             invisibly
             )
             impress'd
             ,
             should
             continue
             for
             many
             hours
             a
             Source
             of
             Corporeal
             Effluxes
             ;
             if
             there
             were
             not
             setting
             Dogs
             ,
             and
             Spaniels
             ,
             and
             Bloud-hounds
             ,
             whose
             noses
             can
             take
             notice
             at
             
             that
             distance
             of
             time
             of
             such
             Emanations
             ,
             though
             not
             onely
             other
             sorts
             of
             Animals
             ,
             but
             other
             sorts
             of
             Dogs
             are
             unable
             to
             do
             so
             .
          
           
             I
             saw
             a
             stone
             in
             the
             hands
             of
             an
             Academick
             ,
             an
             Acquaintance
             of
             mine
             ,
             which
             I
             should
             by
             the
             Eye
             have
             judg'd
             to
             be
             an
             Agate
             ,
             not
             a
             Blood
             stone
             ,
             and
             consequently
             I
             should
             not
             have
             thought
             that
             it
             could
             have
             communicated
             Medicinal
             Effluvia
             appropriated
             to
             excessive
             Bleeding
             ,
             if
             the
             Wearer
             of
             it
             had
             not
             been
             subject
             to
             that
             Disease
             ,
             and
             had
             not
             often
             cur'd
             both
             himself
             and
             others
             ,
             by
             wearing
             this
             stone
             about
             his
             neck
             ;
             which
             if
             he
             left
             off
             ,
             as
             sometimes
             he
             did
             for
             Trials
             sake
             ,
             his
             exceedingly
             sanguine
             complexion
             (
             to
             which
             I
             have
             rarely
             seen
             a
             Match
             )
             would
             in
             a
             few
             daies
             cast
             him
             into
             Relapses
             .
             What
             I
             have
             elsewhere
             told
             you
             about
             the
             true
             virtues
             of
             some
             Stones
             ,
             (
             for
             I
             fear
             that
             most
             of
             those
             that
             are
             wont
             to
             be
             ascrib'd
             to
             them
             are
             false
             ,
             )
             may
             give
             some
             confirmation
             to
             what
             I
             have
             been
             delivering
             ,
             which
             I
             cannot
             now
             stay
             to
             do
             ,
             being
             to
             draw
             to
             a
             Conclusion
             as
             soon
             as
             I
             have
             put
             you
             in
             mind
             ,
             that
             it
             would
             not
             probably
             have
             ever
             been
             expected
             that
             so
             ponderous
             and
             solid
             a
             Body
             as
             the
             Loadstone
             should
             be
             invironed
             by
             an
             Atmosphere
             ,
             if
             Iron
             had
             been
             a
             scarce
             Mineral
             ,
             and
             had
             not
             chanc'd
             to
             have
             been
             plac'd
             near
             it
             .
          
           
             And
             with
             this
             instance
             I
             shall
             put
             an
             end
             to
             these
             Notes
             ,
             because
             it
             allows
             me
             to
             make
             this
             Reflextion
             ;
             that
             since
             solid
             Bodies
             may
             have
             constant
             Atmospheres
             about
             them
             ,
             and
             yet
             not
             discover
             that
             they
             have
             so
             ,
             but
             by
             their
             operation
             upon
             one
             particular
             Body
             ,
             or
             those
             few
             which
             participate
             of
             That
             ;
             and
             since
             there
             are
             already
             (
             as
             we
             have
             seen
             )
             very
             differing
             wayes
             whereby
             Bodies
             may
             appear
             to
             be
             exhaleable
             ,
             it
             is
             not
             unlikely
             that
             there
             may
             be
             more
             and
             more
             Bodies
             (
             even
             of
             those
             that
             are
             solid
             and
             hard
             )
             found
             to
             emit
             Effluvia
             ,
             as
             more
             and
             more
             wayes
             of
             discovering
             that
             they
             do
             so
             ,
             shall
             either
             by
             chance
             or
             industry
             be
             brought
             to
             light
             .
          
           
             FINIS
             .
          
        
      
    
     
       
         
         
           The
           CONTENTS
           .
        
         
           
             Experiment
             1.
             
          
           
             ABout
             the
             raising
             of
             Mercury
             to
             a
             great
             height
             in
             an
             open
             Tube
             ,
             by
             the
             Spring
             of
             a
             litle
             included
             Air.
             2
          
           
             VVherein
             is
             set
             down
             the
             height
             the
             Mercury
             was
             raisd
             to
             ,
             p.
             3.
             its
             sudden
             ascent
             upon
             the
             first
             Suck
             ,
             with
             the
             vibrations
             it
             makes
             before
             it
             settles
             :
             what
             proportion
             of
             height
             it
             has
             upon
             the
             several
             Exuctions
             ,
             and
             what
             height
             the
             Mercury
             was
             at
             in
             the
             Barometer
             at
             the
             time
             of
             the
             trials
             of
             this
             Experiment
             .
             p.
             2.
             3.
             4.
             as
             also
             what
             the
             quantity
             of
             the
             included
             Air
             was
             ,
             and
             how
             the
             Experiment
             may
             be
             made
             use
             of
             against
             those
             ,
             that
             in
             the
             explication
             of
             the
             Torricellian
             Experiment
             recur
             to
             a
             Funiculus
             or
             a
             
               fuga
               vacui
               .
               p.
            
             5.
             6
          
        
         
           
             Experiment
             2.
             
          
           
             Shewing
             ,
             that
             much
             included
             Air
             rais'd
             Mercury
             in
             an
             open
             Tube
             ,
             no
             higher
             than
             the
             weight
             of
             the
             Atmosphere
             may
             in
             a
             Baroscope
             .
             7
          
           
             The
             reason
             that
             induc'd
             the
             Authour
             to
             think
             it
             would
             be
             so
             :
             the
             successe
             of
             the
             Experiment
             ,
             and
             notice
             taken
             of
             the
             great
             force
             of
             the
             Spring
             of
             the
             Air
             then
             when
             it
             could
             not
             raise
             the
             Mercury
             any
             higher
             .
             8.
             9.
             10.
             
          
        
         
           
             Experiment
             3.
             
          
           
             Shewing
             that
             the
             Spring
             of
             the
             included
             Air
             will
             raise
             Mercury
             to
             almost
             equal
             heights
             in
             very
             unequal
             Tubes
             .
             10
          
           
             Of
             the
             allowance
             that
             is
             to
             be
             made
             for
             the
             weakning
             of
             the
             Spring
             of
             the
             Air
             ,
             whilst
             it
             expands
             it self
             into
             the
             place
             of
             a
             larger
             Cylinder
             of
             Mercury
             ,
             together
             with
             the
             Reason
             why
             this
             and
             the
             former
             Experiment
             were
             not
             tried
             in
             water
             ,
             as
             also
             an
             account
             of
             an
             adventitious
             Spring
             that
             was
             superadded
             to
             the
             Air
             by
             heat
             .
             11.
             12.
             13
          
        
         
           
             Experiment
             4.
             
          
           
             About
             a
             new
             Hydraulo-pneumatical
             Fountain
             ,
             made
             by
             the
             Spring
             of
             uncompress'd
             Air.
             13.
             
          
           
             
             Several
             directions
             for
             it
             .
             14.
             15.
             
             The
             uses
             to
             be
             made
             of
             it
             ;
             as
             in
             Hydraulo-pneumaticks
             ,
             or
             to
             shew
             by
             what
             degrees
             the
             Air
             restores
             it self
             to
             its
             Spring
             ,
             or
             especially
             to
             find
             what
             kind
             of
             line
             the
             salient
             water
             describes
             in
             rarified
             Air.
             16.
             &c.
             
          
        
         
           
             Experiment
             5.
             
          
           
             About
             a
             way
             of
             speedily
             breaking
             flat
             Glasses
             by
             the
             weight
             of
             the
             Atmosphere
             .
             18
          
        
         
           
             Experiment
             6.
             
          
           
             Shewing
             ,
             that
             the
             breaking
             of
             Glass
             plates
             in
             the
             foregoing
             Experiment
             ,
             need
             not
             to
             be
             ascrib'd
             to
             the
             
               Fuga
               Vacui
            
             .
             19
          
        
         
           
             Experiment
             7.
             
          
           
             About
             a
             convenient
             way
             of
             breaking
             blown
             Bladders
             by
             the
             Spring
             of
             the
             Air
             included
             in
             them
             .
             20
          
           
             And
             of
             the
             usefulness
             of
             this
             Experiment
             in
             other
             tryals
             .
             21
          
        
         
           
             Experiment
             8.
             
          
           
             About
             the
             lifting
             up
             a
             considerable
             Weight
             by
             the
             bare
             Spring
             of
             a
             litle
             Air
             included
             in
             a
             Bladder
             .
             22
          
           
             VVith
             a
             hint
             that
             this
             may
             not
             be
             unserviceable
             for
             the
             explanation
             of
             the
             Muscles
             .
             23
          
        
         
           
             Experiment
             9.
             
          
           
             About
             the
             breaking
             of
             Hermetically
             seal'd
             Bubbles
             of
             Glass
             by
             the
             bare
             Spring
             of
             their
             own
             Air.
             24
          
           
             That
             they
             broke
             not
             presently
             ,
             and
             what
             the
             reason
             might
             be
             of
             the
             slowness
             of
             that
             effect
             .
             ib.
             25
          
        
         
           
             Experiment
             10.
             
          
           
             Containing
             two
             or
             three
             Tryals
             of
             the
             force
             of
             the
             Spring
             of
             our
             Air
             uncompress'd
             upon
             stable
             and
             even
             solid
             Bodies
             ,
             (
             whereto
             t
             is
             external
             .
             )
             25
          
           
             Several
             trials
             of
             it
             with
             different
             circumstances
             ,
             that
             the
             vessels
             broke
             not
             here
             neither
             immediately
             upon
             the
             last
             Exuction
             :
             27
          
           
             with
             a
             Note
             necessary
             for
             the
             practise
             of
             one
             of
             the
             Trials
             .
             28
          
        
         
           
             Experiment
             11.
             
          
           
             Shewing
             ,
             that
             Mercury
             will
             in
             Tubes
             be
             raised
             by
             Suction
             no
             higher
             
             than
             the
             weight
             of
             the
             Atmosphere
             is
             able
             to
             impell
             it
             up
             .
             29
          
           
             The
             principle
             of
             the
             Schoolmen
             of
             a
             
               fuga
               vacui
            
             shewn
             to
             be
             insufficient
             ,
             as
             also
             the
             supposition
             of
             a
             
               Funiculus
               .
               30
               &c.
            
             
          
           
             Some
             particulars
             to
             be
             taken
             notice
             of
             concerning
             the
             exhausting
             a
             Siphon
             ,
             an
             instrument
             of
             frequent
             use
             in
             these
             Experiments
             .
             32.
             33
          
        
         
           
             Experiment
             12.
             
          
           
             About
             the
             differing
             heights
             whereto
             Liquors
             will
             be
             elevated
             by
             Suction
             ,
             according
             to
             their
             several
             specifick
             Gravities
             .
             34
          
           
             Notice
             given
             ,
             that
             the
             proportion
             of
             the
             Specifick
             gravity
             of
             Mercury
             to
             water
             is
             not
             quite
             as
             14
             to
             1.
             35.
             36
          
           
             The
             notion
             of
             a
             
               fuga
               vacui
            
             unreasonable
             .
             ib.
             
          
           
             The
             use
             that
             may
             be
             made
             of
             this
             experiment
             in
             the
             estimating
             the
             gravity
             of
             several
             liquors
             ,
             with
             some
             tryals
             thereupon
             .
             36.
             37.
             38
          
        
         
           
             Experiment
             13.
             
          
           
             About
             the
             heights
             to
             which
             Water
             and
             Mercury
             may
             be
             raised
             ,
             proportionably
             to
             their
             specifick
             Gravities
             ,
             by
             the
             Spring
             of
             the
             Air.
             38
          
        
         
           
             Experiment
             14.
             
          
           
             About
             the
             heights
             answerable
             to
             their
             respective
             Gravities
             ,
             to
             which
             Mercury
             and
             Water
             will
             subside
             ,
             upon
             the
             withdrawing
             of
             the
             Spring
             of
             the
             Air.
             39.
             &c.
             
          
           
             VVith
             notice
             of
             the
             difficulty
             of
             the
             Trial
             ,
             and
             the
             allowance
             that
             must
             be
             made
             in
             it
             .
             ib.
             
          
        
         
           
             Experiment
             15.
             
          
           
             About
             the
             greatest
             height
             to
             which
             Water
             can
             be
             rais'd
             by
             Attraction
             or
             sucking-Pumps
             .
             41
          
           
             The
             motives
             for
             the
             trying
             of
             it
             ,
             the
             apparatus
             .
             42.
             43
          
           
             The
             height
             of
             the
             water
             ,
             the
             same
             compar'd
             to
             that
             of
             the
             Quick-silver
             at
             the
             same
             time
             in
             a
             Baroscope
             ,
             and
             examin'd
             according
             to
             the
             proportion
             of
             their
             specifick
             Gravities
             .
             44.
             &c.
             
          
           
             Some
             circumstances
             delivered
             ,
             that
             induced
             the
             Author
             to
             think
             the
             trial
             was
             exactly
             enought
             performed
             .
             46.
             47
          
           
             An
             intimation
             given
             of
             the
             difference
             there
             may
             be
             in
             these
             kind
             of
             trials
             from
             the
             varying
             weight
             of
             the
             Atmosphere
             .
             49
          
           
             
             A
             mistake
             of
             VVriters
             of
             Hydraulicks
             in
             the
             conceit
             of
             carrying
             water
             over
             never
             so
             high
             mountains
             .
             49.
             50
          
        
         
           
             Experiment
             16.
             
          
           
             About
             the
             bending
             of
             a
             Springy
             body
             in
             the
             Exhausted
             Receiver
             .
             50
          
           
             No
             alteration
             of
             the
             Spring
             discovered
             .
             52
          
        
         
           
             Experiment
             17.
             
          
           
             About
             the
             making
             of
             Mercurial
             ,
             and
             other
             Gages
             ,
             whereby
             to
             estimate
             how
             the
             Receiver
             is
             exhausted
             .
             52
          
           
             Several
             Gages
             mentioned
             .
             53.
             
             One
             preferr'd
             and
             describ'd
             ,
             and
             directions
             for
             it
             given
             .
             54.
             &c.
             Two
             other
             Gages
             useful
             ,
             when
             t
             is
             not
             requir'd
             the
             Engine
             should
             be
             very
             much
             exhausted
             .
             58.
             59
          
        
         
           
             Experiment
             18.
             
          
           
             About
             an
             easie
             way
             to
             make
             the
             Pressure
             of
             the
             Air
             sensible
             to
             the
             Touch
             of
             those
             that
             doubt
             of
             it
             .
             59
          
           
             VVith
             a
             Caution
             in
             using
             of
             it
             .
             61
          
        
         
           
             Experiment
             19.
             
          
           
             About
             the
             subsidence
             of
             Mercury
             in
             the
             Tube
             of
             the
             Torricellian
             Experiment
             to
             the
             level
             of
             the
             stagnant
             Mercury
             .
             61
          
           
             Some
             confirmations
             of
             what
             had
             been
             said
             in
             the
             first
             Treatise
             of
             the
             Physico-Mechanical
             Experiments
             .
             Exp.
             17.
             62.
             63
          
        
         
           
             Experiment
             20.
             
          
           
             Shewing
             ,
             that
             in
             Tubes
             open
             at
             both
             ends
             ,
             when
             no
             
               fuga
               Vacui
            
             can
             be
             pretended
             ,
             the
             weight
             of
             Water
             will
             raise
             Quick-silver
             no
             higher
             in
             slender
             than
             in
             larger
             Pipes
             .
             63
          
           
             Two
             Tryals
             ,
             one
             with
             Tubes
             of
             several
             bignesses
             open
             at
             both
             ends
             .
             64.
             65.
             the
             other
             with
             them
             after
             the
             Torricellian
             way
             .
             65.
             66
          
        
         
           
             Experiment
             21.
             
          
           
             Of
             the
             Heights
             at
             which
             pure
             Mercury
             ,
             and
             Mercury
             Amalgam'd
             with
             Tin
             ,
             will
             stand
             in
             Barometers
             .
             66
          
           
             A
             Note
             concerning
             the
             inconvenience
             ,
             if
             the
             Amalgam
             be
             too
             thick
             :
             the
             use
             that
             may
             be
             made
             of
             this
             Experiment
             ,
             to
             discover
             how
             much
             two
             mixt
             Bodies
             penetrate
             one
             another
             ,
             as
             also
             to
             further
             illustrate
             that
             the
             height
             of
             the
             Liquors
             in
             the
             Torricellian
             Experiment
             depends
             upon
             the
             Aequilibrium
             with
             the
             outward
             Air.
             67
          
        
         
           
           
             Experiment
             22.
             
          
           
             Wherein
             is
             proposed
             away
             of
             making
             Barometers
             ,
             that
             may
             be
             transported
             even
             to
             distant
             Countries
             .
             68
          
           
             The
             figure
             the
             Barometer
             is
             to
             be
             of
             ,
             the
             way
             of
             filling
             it
             ,
             putting
             it
             into
             a
             Frame
             ,
             and
             securing
             it
             from
             the
             harm
             the
             Mercury
             its
             self
             might
             do
             in
             the
             Transportation
             by
             its
             moving
             up
             and
             down
             in
             the
             upper
             empty
             part
             .
             69.
             70.
             
             &c.
             
          
           
             The
             great
             serviceableness
             of
             this
             Instrument
             ,
             with
             an
             intimation
             of
             others
             of
             a
             different
             kind
             .
             74.
             75
          
           
             A
             Postscript
             advertising
             ,
             that
             there
             has
             been
             since
             some
             difference
             found
             betwixt
             an
             ordinary
             Baroscope
             and
             these
             Travailing
             ones
             ,
             with
             a
             guess
             at
             the
             reason
             of
             it
             ,
             and
             that
             for
             all
             this
             the
             portable
             Baroscopes
             may
             be
             serviceable
             .
             76.
             77
          
        
         
           
             Experiment
             23.
             
          
           
             Confirming
             ,
             that
             Mercury
             in
             a
             Barometer
             will
             be
             kept
             suspended
             higher
             at
             the
             top
             ,
             than
             at
             the
             bottom
             of
             a
             Hill.
             On
             which
             occasion
             something
             is
             noted
             about
             the
             height
             of
             Mountains
             ,
             especially
             the
             Pic
             of
             Tenariff
             .
             77
          
           
             Other
             Authors
             Opinions
             about
             it
             examined
             .
             80
          
           
             A
             more
             moderate
             height
             allow'd
             than
             that
             asserted
             by
             
               Ricciolus
               .
               81.
               82.
            
             with
             a
             consideration
             to
             be
             had
             in
             the
             measuring
             the
             altitude
             of
             Mountains
             distant
             from
             the
             Sea.
             84
          
        
         
           
             Experiment
             24.
             
          
           
             Shewing
             ,
             that
             the
             Pressure
             of
             the
             Atmosphere
             may
             be
             exercis'd
             enough
             to
             keep
             up
             the
             Mercury
             in
             the
             Torricellian
             Experiment
             ,
             though
             the
             Air
             presse
             upon
             it
             at
             a
             very
             small
             Orifice
             .
             85
          
        
         
           
             Experiment
             25.
             
          
           
             Shewing
             ,
             that
             an
             oblique
             pressure
             of
             the
             Atmosphere
             may
             suffice
             to
             keep
             up
             the
             Mercury
             at
             the
             wonted
             height
             in
             the
             Torricellian
             Experiment
             ,
             and
             that
             the
             spring
             of
             a
             litle
             included
             Air
             may
             do
             the
             same
             .
             87
          
           
             VVhat
             use
             may
             be
             made
             of
             the
             former
             Experiment
             for
             a
             portable
             Baroscope
             .
             88.
             89
          
        
         
           
           
             Experiment
             26.
             
          
           
             About
             the
             making
             of
             a
             Baroscope
             (
             but
             of
             litle
             practical
             use
             )
             that
             serves
             but
             at
             certain
             times
             .
             90
          
           
             The
             Argument
             it
             affords
             against
             a
             
               fuga
               Vacui
               .
               ib.
            
             
          
        
         
           
             Experiment
             27.
             
          
           
             About
             the
             Ascension
             of
             Liquors
             in
             very
             slender
             Pipes
             in
             an
             Exhausted
             Receiver
             .
             91
          
        
         
           
             Experiment
             28.
             
          
           
             About
             the
             great
             and
             seemingly
             spontaneous
             Ascension
             of
             Water
             in
             a
             Pipe
             fill'd
             with
             a
             compact
             body
             ,
             whose
             Particles
             are
             thought
             incapable
             of
             imbibing
             it
             .
             93
          
           
             By
             it
             an
             Explication
             that
             has
             been
             made
             of
             the
             cause
             of
             Filtration
             examined
             .
             A
             probable
             cause
             of
             the
             Ascension
             of
             Sap
             into
             trees
             hence
             suggested
             .
             An
             attempt
             to
             make
             a
             Syphon
             ,
             that
             should
             run
             of
             it self
             without
             Suction
             .
             95.
             96
          
        
         
           
             Experiment
             29.
             
          
           
             Of
             the
             seemingly
             spontaneous
             ascension
             of
             Salts
             along
             the
             sides
             of
             Glasses
             ,
             with
             a
             conjecture
             at
             the
             Cause
             of
             it
             .
             97
          
        
         
           
             Experiment
             30.
             
          
           
             About
             an
             attempt
             to
             measure
             the
             Gravity
             of
             the
             Cylinders
             of
             the
             Atmosphere
             ,
             so
             as
             that
             it
             may
             be
             exprest
             by
             known
             and
             common
             weights
             .
             101
          
           
             Wherein
             also
             the
             specifick
             Gravities
             of
             Mercury
             and
             VVater
             are
             compared
             .
             102
          
        
         
           
             Experiment
             31.
             
          
           
             About
             the
             Attractive
             virtue
             of
             the
             Loadstone
             in
             an
             Exhausted
             Receiver
             .
             105
          
        
         
           
             Experiment
             32.
             
          
           
             Shewing
             ,
             that
             when
             the
             Pressure
             of
             the
             External
             Air
             is
             taken
             off
             ,
             t
             is
             very
             easie
             to
             draw
             up
             the
             Sucker
             of
             a
             Syringe
             ,
             though
             the
             Hole
             ,
             at
             which
             the
             Air
             or
             VVater
             should
             succeed
             ,
             be
             stopt
             .
             106
          
           
             The
             first
             Tryal
             .
             107.
             
             The
             
               2
               d
            
             Tryal
             ,
             containing
             a
             variation
             of
             the
             foregoing
             .
             109
          
        
         
           
           
             Experiment
             33.
             
          
           
             About
             the
             opening
             of
             a
             Syringe
             ,
             whose
             Pipe
             was
             stopt
             in
             the
             exhausted
             Receiver
             ,
             and
             by
             the
             help
             of
             it
             making
             the
             pressure
             of
             the
             Air
             lift
             up
             a
             considerable
             weight
             .
             111
          
        
         
           
             Experiment
             34.
             
          
           
             Shewing
             ,
             that
             the
             cause
             of
             the
             ascension
             of
             Liquors
             in
             Syringes
             is
             to
             be
             derived
             from
             the
             pressure
             of
             the
             Air.
             113
          
           
             Exemplified
             in
             three
             several
             Tryals
             .
             113.
             115.
             117
          
        
         
           
             Experiment
             35.
             
          
           
             Shewing
             ,
             that
             upon
             the
             pressure
             of
             the
             Air
             depends
             the
             sticking
             of
             Cupping-glasses
             to
             the
             fleshy
             parts
             they
             are
             apply'd
             to
             .
             118
          
        
         
           
             Experiment
             36.
             
          
           
             About
             the
             making
             ,
             without
             heat
             ,
             a
             Cupping-Glass
             to
             lift
             up
             a
             great
             weight
             .
             122
          
        
         
           
             Experiment
             37.
             
          
           
             Shewing
             ,
             that
             Bellows
             ,
             whose
             nose
             is
             very
             well
             stopt
             ,
             will
             open
             of
             themselves
             ,
             when
             the
             pressure
             of
             the
             external
             Air
             is
             taken
             off
             .
             124
          
        
         
           
             Experiment
             38.
             
          
           
             About
             an
             attempt
             to
             examine
             the
             Motions
             and
             Sensibility
             of
             the
             Cartesian
             
               Materia
               subtilis
            
             ,
             or
             the
             Aether
             with
             a
             pair
             of
             Bellows
             (
             made
             of
             a
             Bladder
             )
             in
             the
             exhausted
             Receiver
             .
             127
          
        
         
           
             Experiment
             39.
             
          
           
             About
             a
             farther
             attempt
             to
             prosecute
             the
             Inquiry
             propos'd
             in
             the
             fore-going
             .
             Experiment
             .
             132
          
           
             First
             with
             a
             Syringe
             and
             a
             Feather
             .
             132.
             133.
             
             &c.
             
          
           
             Then
             with
             a
             Syringe
             in
             water
             .
             136
          
           
             If
             there
             be
             an
             Aether
             ,
             what
             kind
             of
             body
             it
             must
             be
             ,
             with
             a
             confirmation
             of
             the
             
               34
               th
            
             Experiment
             .
             138
          
        
         
           
             Experiment
             40.
             
          
           
             About
             the
             falling
             ,
             in
             the
             exhausted
             Receiver
             ,
             of
             a
             light
             body
             ,
             fitted
             to
             have
             its
             motion
             visibly
             varied
             by
             a
             small
             resistance
             of
             the
             Air.
             139
          
           
             A
             Design
             mentioned
             to
             try
             this
             way
             ,
             what
             the
             degrees
             of
             celerity
             would
             be
             of
             descending
             bodies
             in
             an
             exhausted
             Receiver
             .
             141
          
           
             A
             Caution
             given
             concerning
             this
             present
             Experiment
             .
             ib.
             
          
           
             
             Directions
             given
             ,
             which
             way
             to
             lengthen
             Receivers
             for
             the
             Trial
             of
             this
             and
             other
             Experiments
             .
             142
          
        
         
           
             Experiment
             41.
             
          
           
             About
             the
             propagation
             of
             Sounds
             in
             the
             exhausted
             Receiver
             .
             143
          
           
             A
             Contrivance
             describ'd
             necessary
             for
             this
             and
             divers
             Experiments
             .
             144
          
           
             The
             Trial
             perform'd
             by
             it
             .
             145.
             146
          
           
             Another
             Trial
             with
             an
             Alarum
             watch
             .
             146.
             147
          
           
             An
             assertion
             of
             Mersennus
             examined
             :
             a
             proposal
             of
             his
             shewn
             to
             be
             unpracticable
             .
             148.
             149
          
           
             A
             mention
             of
             some
             other
             Trials
             designed
             concerning
             Sound
             .
             149.
             150
          
        
         
           
             Experiment
             42.
             
          
           
             About
             the
             breaking
             of
             a
             Glass-drop
             in
             an
             Exhausted
             Receiver
             .
             150
          
           
             VVherein
             an
             Hypothesis
             ,
             ascribing
             the
             cause
             of
             the
             breaking
             of
             them
             to
             the
             force
             of
             the
             external
             Air
             ,
             is
             examined
             .
             ib.
             
          
        
         
           
             Experiment
             43.
             
          
           
             About
             the
             production
             of
             Light
             in
             the
             exhausted
             Receiver
             .
             151
          
        
         
           
             Experiment
             44.
             
          
           
             About
             the
             production
             of
             a
             kind
             of
             Halo
             ,
             and
             Colours
             in
             the
             Exhausted
             Receiver
             .
             152
          
           
             The
             reason
             of
             it
             proposed
             ,
             with
             a
             suggestion
             that
             the
             same
             cause
             might
             have
             been
             of
             that
             Apparition
             of
             Light
             mentionea
             in
             the
             formerly
             publisht
             Experiments
             .
             153.
             154
          
        
         
           
             Experiment
             45.
             
          
           
             About
             the
             production
             of
             Heat
             by
             Attrition
             in
             the
             exhausted
             Receiver
             .
             154
          
        
         
           
             Experiment
             46.
             
          
           
             About
             the
             slaking
             of
             Quick-Lime
             in
             the
             Exhausted
             Receiver
             .
             157
          
        
         
           
             Experiment
             47.
             
          
           
             About
             an
             attempt
             made
             to
             measure
             the
             force
             of
             the
             Spring
             of
             included
             Air
             ,
             and
             examine
             a
             Conjecture
             about
             the
             difference
             of
             its
             strength
             in
             unequally
             broad
             mouth'd
             Vessels
             .
             158
          
           
             The
             first
             Trial
             by
             a
             Syringe
             ;
             159
          
           
             
             Another
             different
             Trial
             ;
             the
             successe
             of
             which
             is
             summarily
             related
             ,
             and
             the
             way
             of
             making
             the
             Experiment
             delivered
             :
             160.
             &c.
             
          
           
             with
             the
             above
             named
             conjecture
             about
             &c.
             163
          
        
         
           
             Experiment
             48.
             
          
           
             About
             an
             easie
             way
             of
             making
             a
             small
             quantity
             of
             included
             Air
             raise
             in
             the
             exhausted
             Receiver
             50
             or
             60
             pound
             ,
             or
             a
             greater
             weight
             .
             165
          
        
         
           
             Experiment
             49.
             
          
           
             About
             the
             weight
             of
             Air.
             168
          
           
             Two
             Notes
             in
             prosecution
             of
             the
             
               36
               th
            
             of
             the
             already
             published
             Experiments
             ,
             concerning
             the
             estimating
             the
             weight
             of
             the
             Air
             ,
             by
             the
             help
             of
             a
             seal'd
             Bubble
             .
             168.
             169
          
           
             Another
             Tryal
             ,
             by
             weighing
             the
             Receiver
             its
             self
             .
             169.
             &c.
             
          
           
             An
             Advertisement
             of
             the
             variation
             of
             the
             gravity
             of
             the
             Air
             ,
             and
             that
             by
             Experiments
             made
             at
             different
             times
             or
             places
             there
             are
             obtain'd
             different
             proportions
             betwixt
             It
             and
             Water
             .
             171.
             172
          
        
         
           
             Experiment
             50.
             
          
           
             About
             the
             disjoyning
             of
             two
             Marbles
             (
             not
             otherwise
             to
             be
             pull'd
             a
             sunder
             without
             a
             great
             weight
             )
             by
             withdrawing
             the
             pressure
             of
             the
             Atmosphere
             .
             172
          
           
             NOTES
             &c.
             about
             the
             Atmospheres
             of
             Consistent
             Bodies
             (
             here
             below
             :
             )
             177
          
           
             An
             advertisement
             ,
             shewing
             the
             reason
             why
             these
             Notes
             are
             annex'd
             ,
             and
             what
             discourse
             they
             belong
             to
             .
             179.
             180
          
           
             The
             Proemium
             .
             181
          
           
             That
             there
             are
             such
             Atmosphares
             ,
             prov'd
             
               à
               priori
            
             ,
             both
             from
             the
             Atomical
             and
             Cartesian
             Hypothesis
             .
             182
          
           
             Demonstrated
             by
             particular
             Examples
             in
             several
             Bodies
             .
             183.
             184
          
           
             In
             such
             as
             are
             most
             unlikely
             to
             emit
             Effluvia
             ,
             as
             first
             in
             very
             cold
             bodies
             .
             185.
             186.
             in
             very
             ponderous
             .
             186.
             &c.
             in
             very
             solid
             and
             hard
             bodies
             .
             189.
             &c.
             and
             lastly
             ,
             in
             those
             that
             are
             most
             fixt
             .
             191
             where
             the
             Argument
             of
             Des-Cartes
             against
             Electrical
             emanations
             ,
             
             drawn
             from
             the
             fixednesse
             of
             Glass
             ,
             is
             examined
             .
             192
          
           
             Observations
             about
             the
             exciting
             the
             Electricity
             of
             Bodies
             ,
             as
             that
             of
             Amber
             by
             the
             Sun
             ,
             and
             that
             of
             Glass
             by
             the
             heat
             of
             the
             fire
             .
             193
          
           
             The
             Considerations
             that
             may
             induce
             us
             to
             believe
             ,
             that
             very
             many
             other
             Bodies
             ,
             not
             yet
             discovered
             to
             do
             so
             ,
             emit
             their
             Effluviums
             .
             194.
             &c.
             
          
        
      
       
         
         
           M
           r
           BOYLE'S
           CONTINUATION
           OF
           EXPERIMENTS
           of
           the
           Air.
           
        
      
       
         
         
           
             
               The
               VIII
               .
               Plate
            
          
        
         
         
           
             
               Plate
               the
               VII
               .
            
          
        
         
         
           
             
               The
               V
               Plate
            
          
        
         
         
           
             
               The
               6
               Plate
               .
            
          
        
         
         
           
             
               The
               IV
               Plate
            
          
        
         
         
           
             
               The
               III
               Plate
               .
            
          
        
      
       
         Notes, typically marginal, from the original text
         
           Notes for div A28949-e150
           
             Seneca
             quaest
             .
             nat
             .
             lib.
             7.
             c.
             31.
             
          
        
         
           Notes for div A28949-e1560
           
             See
             plate
             the
             III
             Figure
             the
             
          
           
             See
             the
             latter
             part
             of
             the
             following
             Experiment
             .
          
           
             See
             plate
             the
             Figure
             the
             
          
           
             10.
             
             The
             same
             reasons
             which
             made
             
               Instrumental
               Musick
            
             fit
             for
             Sacrifices
             in
             the
             Apostles
             days
             make
             it
             fit
             still
             .
          
           
             
               Pli.
               l.
            
             x.
             Ep.
             
          
           
             1
             Sam.
             x.
             5.
             
             Chr.
             xxv
             .
             ●
             .
          
           
             Exp.
             8.
             pag.
             36.
             
          
           
             *
             The
             place
             here
             meant
             is
             a
             passage
             in
             the
             Author's
             Examen
             of
             
               Mr.
               Hobbs
            
             his
             Dialogue
             about
             the
             Air.
             
          
           
             See
             Plate
             the
             Fig.
             the
             and
             the
             Annotations
             at
             the
             close
             of
             this
             Experiment
             .
          
           
             See
             plate
             the
             Figure
             the
             
          
           
             Plate
             the
             Fig.
             the
             
          
           
             See
             plate
             the
             Figure
             the
             
          
           
             *
             In
             Notes
             about
             the
             history
             of
             Elasticity
             .
          
           
             See
             plate
             the
             Figure
             the
             
          
           
             Exper.
             the
             XVII
             .
             pag.
             the
             54
             ,
             and
             55.
             
          
           
             The
             like
             Consideration
             I
             since
             found
             to
             have
             been
             had
             ,
             before
             me
             ,
             by
             the
             learned
             Ricciolus
             .
          
           
             This
             was
             (
             if
             I
             forget
             not
             )
             about
             the
             later
             end
             of
             the
             year
             1662.
             
          
           
             See
             the
             fig.
             of
             the
             plate
             
          
           
             See
             Plate
             the
             Fig.
             the
             
          
           
             See
             plate
             the
             Figure
             the
             
          
           
             See
             Plate
             the
             Fig.
             the
             
          
           
             *
             Page
             the
             105.
             106.
             
          
           
             See
             plate
             the
             Figure
             the
             
          
           
             See
             the
             Figure
             last
             referr'd
             to
             .
          
           
             The
             Contrivance
             here
             mentioned
             may
             be
             conceiv'd
             ,
             by
             considering
             the
             Figure
             belonging
             to
             the
             41.
             
             Experiment
             .
          
           
             *
             pag.
             156.
             
               &c
               ▪
            
          
           
             See
             Plate
             the
             Fig.
             the
             
          
           
             *
             Expe.
             the
             Vth.
             
          
           
             See
             plate
             the
             Figure
             the
             
          
           
             See
             Plate
             the
             Fig.
             the
             
          
           
             *
             viz.
             the
             XXXVI
             .
          
           
             April
             the
             19.
             1662.
             
          
           
             May.
             26.
             1662.
             
          
           
             a
             In
             the
             Hydrostatical
             Paradoxes
             .
          
           
             b
             In
             an
             Appendix
             to
             those
             Paradoxes
             .
          
           
             c
             This
             method
             was
             omitted
             in
             the
             English
             Edition
             of
             the
             newly
             mentioned
             Appendix
             ,
             but
             not
             in
             the
             Latin
             Version
             .
          
           
             *
             Experiment
             the
             XXXI
             .
             See
             also
             the
             cause
             of
             this
             Phaenomenon
             discours'd
             of
             in
             the
             Authors
             History
             of
             Fluidity
             and
             Firmness
             .
          
           
             *
             
               Dr.
               H.
               M.
            
             in
             the
             2d
             .
             chap.
             of
             the
             2d
             .
             Book
             of
             the
             new
             Edition
             (
             in
             folio
             )
             of
             his
             
               Antidote
               against
               Atheism
            
             .