THE PRINCIPLES OF Astronomy and Navigation:  
OR,  
A Clear, Short, yet Full Explanation, of all Circles of the Celestial, and Terrestrial Globes, and of their Uses, being the whole Doctrine of the Sphere, and Hypotheses to the Phenomena of the Primum Mobile.  
To which is Added  
A Discovery of the Secrets of Nature, which are found in the Mercurial-Weather-Glass, etc.  
AS ALSO  
A New Proposal for Buoying up a Ship of any Burden from the Bottom of the Sea.  
By GEORGE SINCLAR, sometime Professor of Philosophy in the College of GLASGOW.  
Edinburgh, Printed by the Heir of Andrew Anderson, Printer to His most Sccred Majesty, Anno d 〈…〉   


Academiae Cantabrigiensis Liber.    

To the Right Honourable MAGNUS' PRINCE, Lord Provost;  
Alexander Brand, Alexander Simpson, john Morray, and William Montgomery, Bailies; james Nicolson Dean of Gilled, Edward Marjorebanks Thesaurer; and remanent Members of the Honourable Senate, of the Ancient City of Edinburgh. May it please your Lordship, and the Honourable Senate,  
IT is neither Ambition, nor Ignorance of your Worth and Merit, which have inclined me, to prefix your Names to the Frontispiece of this mean Pamphlet, but the sure experience I have of your encouraging all virtuous Actions and Learning. What I have now in Equity and Reason presented, I humbly desire the Honourable Senate, may accept favourably. I owe all I have, and myself too, to your Devotion and Service. I choose rather to be doing somewhat Amiss, than doing Nothing. 'Tis the Widow's Mite, which I have sheltered under the Wings of your Protection. If I should endeavour, but to recapitulat, what Sentiments of your Kindness I have found, both Time, and my Memory would fail me. None can think, that there is any Deserving in me, which can be proportionable to those unvaluable Acts of your Bounty. If there be any, I am confident, it is too too scanty to Oblige. When I was able to do more, none were found more willing. I endeavoured indeed, according to my Capacity, to contribute my Assistance for promoving that great and noble Design, which was accomplished; for which the Generations to come, shall call you Happy, whom you have Enriched, with Refreshing-Streams of Cooling-Waters, more Advantageous and Useful to the City, than the Fruit of the Vine. I cannot satisfy all the Obligations to Duty, which lie upon me. The more I was inclined to offer this Trifle, the more I was overcome with Reasons persuading to the contrary. But the uprightness of my Intention, to beautify this trivial Subject, with the Splendour, and Glory of your Names, will excuse the failings of my Understanding. I cannot remunerat the Kindness of the Honourable Senate, better, than by Hearty Prayer, that the LORD may give you, the Spirit of Wisdom, and Government, to Manage the Weighty Affairs of the City, and His Conduct, not only to Guide each one of you, in his particular Calling, but all of you, to the endless Fruition of Immortal Life. This I fervently wish, while I am  
Your Lordships and the Councils, much Obliged Servant, GEORGE SINCLAR.   

TO THE READER.  
I judge it altogether needless to Preface any thing by way of Commendation to the following Tracts. They will (I hope) commend themselves, to the intelligent Reader. There is first, The Doctrine of the Sphere, so compendiously set down, that nothing can either be Added, or Subtracted. It is the very Rudiments of Astronomy and Navigation, and of many other Mathematical Sciences. By the use of the Globes, the whole Doctrine of the Sphere may be easily comprehended, even by the meanest Capacity. The second Tract, is not so evident, because more Physical, and less Mathematical, but perhaps as sure. I have set down my own Thoughts only, If any Man shall offer to salve the Phenomena better, I shall be glad. The third Tract is, a new Invention for Buoying up of Ships from the Ground of the Sea. This Proposal was made some few Years ago, to try the Invention and Wit of some Notional Men, but though they have ploughed with my Heifer, yet were they not able, to find out my Riddle: Nay some of them were so confident to aver, that when this Proposal was made to them, How to make a Vessel Sail below the Water; they Replied, it might be easily resolved by their Analytics.   

ERRATA.  
IN the second Tract, Page 28. line 13. for earthly read earthy. pag. 33. lin. ult. for Idaea read Idea.   

THE PRINCIPLES OF Astronomy and Navigation.  

CHAP. I. Of the Circles of the Sphere in general.  
THE material Sphere, is an Instrument, whereby all the Phenomena of the Primum Mobile, are most easily known.  
It is composed of Ten Circles chiefly, which are, the Equinoctial, the Zodiac, the two Colours, the Horizon, the Meridian, the two Tropics, and the two Polars.  
Those Circles, are three manner of ways distinguished among themselves. First, Some of them are called Circuli Maximi, the Greatest Circles; others are called Circuli Minores, the lesser Circles. The Greatest are, the Equinoctial, the Zodiac, the two Colours, the Horizon, and the Meridian; because there cannot be greater Circles in the Sphere, than they are.  
The lesser Circles are, the two Tropics, and the two Polars. They are so called, because there are found in the Sphere greater ones.  
Secondly, The Circles of the Material Sphere, while the Primum Mobile is turning about, are either Parallel one to another, Right, or Oblique, that is, to lie crossly. The Parallel Circles, are the two Polars, the two Tropics, and the Equinoctial, which lie middle between them, together with their Equinoctial, who live under the Poles. The Oblique Circles are, the Zodiac, and the Oblique Horizon. For this cutteth the Equinoctial, at Oblique Angles; the other by reason of its Situation doth the same to the rest of the Circles. The Circles called Right Circles, are the two Colours, the Meridian, and the Right Horizon, because they cut the Equinoctial at Right Angles.  
Thirdly, The Circles of the Sphere, are either Movable, or immovable. The Movable Circles, are these which are turned about with the Sphere, being eight in number, to wit, the Equinoctial, the Zodiac, the Equinoctial Colour, the Solstice Colour, the Tropic of Cancer, the Tropic of Capricorn, the Polar Arctic, and the Polar Antarctic. The Circles immovable, are the Meridian, and the Horizon; so called, because while the Sphere is carried about, they stand steadfast, and unmoveable.   

CHAP. II. Of the Equinoctial.  
THe Equinoctial, is one of the greatest Circles, of the Sphere Movable, and equally distant from the Poles of the World. It is called one of the greatest, that it may be distinguished from the lesser, as well from those, which are fixed in the Sphere, as from others, which we must imagine to be in it. It is called Movable, that it may be distinguished, from the Horizon of those, who live under the Poles, which coinciding with the Equinoctial, must differ from it in this, that the one is Movable, the other Immovable. Lastly, by reason of the third difference (equally distant from the Poles of the Sphere) it is distinguished from the Oblique, and Right Circles of the Sphere.  
It is called by divers Names. For sometimes it is called the Equator, sometimes the Equinoctial, and sometimes the Middle, and greatest of the Parallels.  
The Uses and Offices of the Equinoctial are these. 1. It measureth the first Motion. For this Circle, of all the Circles of the Sphere, under any Position whatsoever, moveth equally; and therefore, it ought to be also the Measure of Time, it being most fit for determining the quantity of the Artificial, and Natural Days. For this cause, it is, that the Degrees of the Equinoctial, are called by some, Tempora, Times. 2. It pointeth forth to us in the Ecliptic, the two Equinoctial Points; those Points, in which the Equinoctial, and Ecliptic cut one another, in the beginning of Aries and Libra. For when the Sun cometh to these Points, the Day and the Night are of equal length over all the Earth, which falleth out on the 10 or 11 of March, and on the 13 or 14 of September. 3. That which is Anomolous, and Irregular in the Oblique Motion of the Zodiac, is reduced to a sure Rule, by the help of the Equinoctial. 4. It divideth the Sphere into two equal parts; the one called the North part, in which is the Pole, named Polus Septentrionalis, Boreus, or Articus: the other called the South part, in which is the Pole, named Polus Australis, Meridionalis, or Antarticus. 5. By this means, it divideth the Zodiac into six Signs, called Northern Signs, and into other six called Southern Signs. 6. From the Equinoctial are numbered the Declinations of all, and whatsoever Points in Heaven, as well South as North. The Declination of any Point, or Star, is an Arch of a Circle of Declination, measured between the Equinoctial, and the said Point, or Centre of the said Star. Circles of Declinations, are of the Greatest Circles in the Sphere Movable, passing thorough the Poles of the World, and any point given. 7. Upon the Equinoctial, we reckon the Right Ascension of any, or whatsoever Point in Heaven. Right Ascension, is nothing else, but an Arch of the Equinoctial, measured between the first Point of Aries, and that Circle of Declination, which passes thorough the point given. 8. Upon the same Equinoctial, we measure the Oblique Ascension, and Descension of any point in Heaven whatsoever. Oblique Ascension, is an Arch of the Equinoctial, measured between the first Point of Aries, and that Point of the Equinoctial, which riseth in the same Moment of Time, with the Point given. Oblique Descension, is an Arch of the Equinoctial measured between the Point foresaid, and that Point of the Equinoctial, which sets in the same Moment of Time, with the Point given. 9 Upon the Equinoctial, we count and reckon the Ascensional Difference, which is nothing else, but an Arch of the Equinoctial, by which Right Ascension differs from Oblique. 10. Upon the Equinoctial, we measure the Rising and Setting Amplitude. This Rising and Setting Amplitude, is nothing else, but an Arch of the Horizon, measured between the Rising, or Setting of the Equinoctial, and the Rising or Setting of any Star, or Point given. 11. Upon the Equinoctial, we number the Longitudes of Places, and upon the same, we reckon the Latitudes of Places. The Longitude of a place, is an Arch of the Equinoctial, measured between the first Meridian, and the Meridian of the Place. The Latitude of a Place, is an Arch of the Meridian measured between the Equinoctial, and Zenith of the Place. 12. The Equinoctial is most useful for making of Sun-dials': for there must be as many Hours upon the Plain, as there are 15 Degrees in the Equinoctial, four and twenty times numbered.   

CHAP. III. Of the Zodiac.  
THe Zodiac, is one of the Greatest Circles of the Sphere, Movable, under which the Planets perpetually haunt.  
The first and second Difference are added, as in the Definition of the Equinoctial. The third, which is in these words (under which the Planets perpetually haunt) do distinguish the Zodiac from all other Circles. For it may come to pass, that, this or that Planet, by his proper motion, may be under the Meridian, may be under some Horary Circle, may touch lightly the Horizon, but that is not always, nor do they always abide in the same Situation: but their stay is perpetual under the Zodiac. And because the Planets wander in the Heavens, viâ obliquâ, therefore this Circle is made oblique, and seeing in this obliquity, they make digression, from this side, to that side, and from that to this, therefore Astronomers have granted to this Circle Latitude, whereby also it may be differenced from all other Circles, none of which ever claimed Latitude.  
The Zodiac is divided, first in relation to its Latitude, into North Latitude, and South Latitude. North Latitude, is that half part of the Zodiac, which from the Ecliptic (the middle Line of it) declines toward the North. South Latitude is opposite to this. Each one of them contains Eight Degrees, whereof the Equinoctial contains 360.  
The Ecliptic, or middle Line of the Zodiac, is one of the Greatest Circles of the Sphere, Movable, under which, the Sun from West to East moves perpetually. This Line, as likewise the Zodiac, is divided according to Longitude into twelve Parts, which are called in Greek 〈◊〉. Every one of these twelve, are subdivided into 30 parts, so that the whole Zodiac contains 360 Degrees. These twelve Divisions are called Aries, Taurus, Gemini, Cancer, Leo, Virgo, Libra, Scorpius, Sagittarius, Cap●…s, Aquarius, Pisces. But seeing there are four Cardinal Points, two of the Equinoctial, and two Solstice Points, it hath pleased Astronome●…, to make the beginning of their reckoning, from the Vernal Equinoctial Point; because the Sun being there, he not only begins the Spring, but openeth the Earth, and giveth life to all Vegetables, and things which grow; which cannot be done, either in any of the Solstices, or when he is in the Autumnal Equinoctial Point. Next, the distinction of the Signs is manifold. For some of them are called Northern Signs, and others are called Southern. The Northern, decline from the Equinoctial towards the North, which are Aries, Taurus, Gemini, Cancer, Leo, Virgo. The Southern decline from the Equinoctial towards the South, which are Libra, Scorpius, Sagittarius, Capricornus, Aquarius, Pisces.  
Secondly, Some of them are called, Signs Ascending, others are called Signs Descending. The first sort, are these, wherein the Sun, and the rest of the Planets do ascend from the South towards our Zenith, which are Capricornus, Aquarius, Pisces, Aries, Taurus, Gemini. The Descending are these, wherein the Sun, and the rest of the Planets, do move from our Zenith towards the South, which are Cancer, Leo, Virgo, Libra, Scorpius, Sagittarius.  
Thirdly, The Signs of the Zodiac, are either Vernal, Estival, Autumnal, or Hybernal. The Vernal, are Aries, Taurus, Gemini. The Estival, are Cancer, Leo, Virgo. Autumnal, are Libra, Scorpius, Sagittarius. And the Hibernal, are Capricornus, Aquarius, Pisces.  
Fourthly, The Signs are either Cardinal, Middle, or Fixed, or Common, or Two-bodied. The Cardinal Signs, are Aries, Cancer, Libra, Capricornus: so called, because their beginnings are the very Cardinal Points. The Middle or Fixed Signs, are Taurus, Leo, Scorpius, Aquarius. They are called Middle or Fixed, because they keep the Middle place between the Cardinal and Common Signs. They are Fixed, because when the Sun is in them, we have a perfect temperament of the Air, agreeing to the given Quadrant of the Heavens. As when the Sun is in Taurus, we have a perfect Spring; in Leo, a perfect Summer; in Scorpius, a perfect Harvest; and in Aquarius, we have a perfect Winter. They are called Common, or Two▪ bodied, as Gemini, Virgo, Sagittarius, and Pisces; because each one of them, hath two Bodies indeed. For Gemini are two Twins. Virgo hath an Ear of Corn in her Hand. Sagittarius is made up of a Man, and a Horse. And lastly, The Fishes are double. They are called Common, because Astrologers find, that they participate of the Nature, both of the Fixed Signs, and the Cardinal which follow.  
Fifthly, The Signs are divided into four Triplicities, which are called by Astrologers Trigons. The first is called the Fiery Trigon, which contains Aries, Leo, and Sagittarius. The second is the Earthy, which contains, Taurus, Virgo, and Capricorn. The third is the Aerial, which contains, Gemini, Libra, and Aquarius. The fourth is the Watery, which contains, Cancer, Scorpius, and Pisces.  
If it happen, that Saturn, and jupiter be in Conjunction this year in Leo, their next Conjunction will happen 20 years after, or truly 19 years, 315 days, and 19 hours, after in Sagittarius. From Sagittarius to Aries, from Aries to Leo, and so in round till 198 years and 236 days passing, they make a Transit into a new Trigon; so that the Revolution of one Trigon, consumes almost 200 year.  
The uses of the Zodiac and Ecliptic are these. 1. As the Equinoctial, is the Measure of the Pri●… Mobile, so is the Zodiac and Ecliptic, the Square and Rule of the second Movables. For as the Sun is always, in or under the Ecliptic; so are the rest of the Planets always, in or under the Zodiac. Therefore as in the Celestial Globe, the Zodiac hath the chief place, so in the Terrestrial Globe the Equinoctial. 2. Upon the Ecliptic we reckon the Longitude of Stars, and from the same Ecliptic, we count their Latitude. The Longitude of a Star, is an Arch of the Ecliptic, measured between ●●e true Equinoctial Point, or beginning of Aries, and the Circle of Latitude passing thorough the Centre of that ●tar. Circles of Latitude, are great Movable Circles, passing thorough the Poles of the Ecliptic, and the Centre ●f the Star given. They are of that ●umber of Circles, which cannot be ●●aced Artificially in the Sphere. Ne●ertheless, of that same Number, is the ●olurus Solstitiorum fixed in the Sphere. The Latitude of a Star, is an Arch of a Circle of Latitude, measured between ●he Ecliptic, and the Centre of the ●tar. 3. According to the Degrees, and ●arts of the Zodiac and Ecliptic, the whole Heavens, and the whole Universe 〈◊〉 divided into twelve Signs; nay every Point contained in the Sphere of the Fixed Stars, is said to be in this or that Sign; though, to be in a Sign, is said many ways. For first, To be in a Sign, is nothing else, but to be under any ●welfth part of the Zodiac. In this ●ense, the Sun is said to ●e in a Sign, because he is always under the Ecliptic. Then the Stars are said to be in a Sign, which are indeed out of the Ecliptic, nevertheless are under the Zodiac. In this sense, the Planets, which wander from the Ecliptic, are said to be in the Sign of Aries, and Taurus, etc. Thirdly, Any thing is said to be in a Sign, which is included, in any of the twelve parts, which arise from the division of the whole Heavens, passing thorough the beginnings of the Dodekatemoria, or the Poles of the Ecliptic; they being six great Circles, which mutually cut one another, in the same Poles. In this sense, any Star, as well fixed, as wand'ring, or new appearing, as a Comet, are said to be in the Sign of Aries, Taurus, etc. 4. The obliquity of the Ecliptic, is the cause of the inequality of days: for seeing it moves unequally, and not evenly, the Sun, which is the true Parent of Time, must of necessity make the days unequal. 5. The Year, the Month, and the four Seasons of the Year, are determined by the Ecliptic. 6. When the Sun and Moon, are both of them in the Ecliptic, of necessity there must be Eclipses; and for this cause, it is called the Ecliptic. 7. How much is the obliquity of the Ecliptic, so much is the distance, between the Poles of the World, and the Poles of the Ecliptic: so much also is the distance, between the Equinoctial, and either of the Tropics.   

CHAP. IU. Of the Colours.  
THe Colours are nothing else, but Circles of Declination, defined above, in the second Chapter of the Equinoctial. They are called Colours from two Greek words, Kolos, or Kolobos, Mancus, maimed or defective, and Oura, Cauda, a Tail, because in an oblique Sphere, they have some part unseen, as if they were maimed, or wantting. But all the rest of the Circles of the Sphere, while it is going about, may be seen: but the Colours, have always some of their parts towards either of the two Poles, lying hid, and unseen. There are only two of them, which use to be placed in the Sphere, one whereof is called the Solstice Colour, the other the Equinoctial Colour. The Equinoctial Colour, is one of the greatest Circles of the Sphere, Movable, passing thorough the Poles of the Sphere, and the Equinoctial Points, the first of Aries, and the first of Libra, which are called Cardinal. By the word movable, the Colours are differenced; First, From the Meridian; Secondly, From the Right Horizon; And thirdly, From the Horary Circles, with all which, by one turning about of the Sphere, they are twice united. But in this they differ, that those do not move, but these follow the motion of the Primum Mobile. The Solstice Colour, is one of the greatest Circles of the Sphere, movable, drawn thorough the Poles of the Sphere, and the two Solstice Points, by which difference, they are distinguished from other Colours.  
The uses of all the Colours in common are these. First, We reckon upon them, the Declinations of all the Points of the Heavens whatsoever. 2. They terminate and bond the Right Ascensions. 3. They are like unto a Right Horizon, and a Meridian in any Sphere, whether Right, Oblique, or Parallel.  
The Uses of the Colours, which are set down in the Sphere, are these in common, 1. Without them, the Parallel Circles in the Material Sphere cannot stand, 2. By their mutual cutting one another, they show the Poles of the Sphere. 3. They divide the Ecliptic into four Quadrants.  
The peculiar Uses of the Equinoctial Colour are these. 1. It demonstrats to us the Equinoctial Points, by its mutual Section, with the Ecliptic; in which Points when the Sun is existing, there is an Universal Equinox over the whole Earth. 2. It is divides the Ecliptic into two halfs, the one called the North part, the other the South part. 3. It distinguishes the Signs, in which when the Sun is existing, the Days are longer than the Nights, from those Signs, in which when the Sun is existing, the Nights are longer than the Days.  
The proper Uses of the Solstice Colour are, 1. It demonstrats to us the two Solstice Points, in which when the Sun is existing, he is either nearest to our Zenith, or furthest removed from it. 2. Upon this Colour, we reckon the Sun's greatest Declination, or the greatest Obliquity of the Ecliptic, which is found to be this day twenty three Degrees, and thirty Minute's. 3. It divides the Zodiac into two halfs; the one called Ascending, the other Descending. 4. It distinguisheth the Signs, in which when the Sun is existing, the Days become longer, and the Nights become shorter, from those Signs, in which when the Sun is existing, the Nights become longer, and the Days become shorter. 5. In this Circle, are the two Poles of the Ecliptic, as many Degrees, distant from the Poles of the World, as the greatest obliquity of the Ecliptic contains. 6. Upon this Colour, the Latitudes of the Zones are determined. For between the Tropics, is contained the breadth of the Torrid Zone, between the Tropics, and the nearest Polar Circles, are contained the two Temperate Zones, and the other two remaining Arches of this Circle, contain the breadth of the two Frigid, or Cold Zones.   

CHAP. V. Of the Horizon.  
THe Horizon, is one of the greatest Circles of the Sphere, Immovable, and equally distant from the Vertical Point. It is called Immovable, that it may be differenced from the rest of the Movable Circles; but especially, First, From their Equinoctial, who live under the Poles. Secondly, From their Ecliptic, whose Zenith is placed in the Polar Circles: for their Ecliptic every day is twice united with their Horizon, but without delay. Thirdly, From their Circles of Declination, or their Colours, who live under the Line: for there, the forementioned Circles, and the Horizon, are twice, by every Revolution of the Sphere, united: but the Circles of Declination follow the Motion of the Primum Mobile, but the Horizon stands Immovable. The Horizon is said indeed to be Immovable, but not Unchangeable, for there are as many Orisons, as there are Vertical Points; and while we change our Vertical Point, of necessity we change our Horizon also.  
Two ways is the Horizon divided. First, In relation to the Equinoctial, which is called a Right Horizon, an Oblique Horizon, and a Parallel Horizon. The Right Horizon, is so called, because it cuts the Equinoctial at Right Angles. It is called Oblique, because it cuts the Equinoctial at Oblique Angles. And it is called a Parallel Horizon, when it lies Parallel to the Plain of the Equinoctial, or rather when it is united, with the Equinoctial. And according to this Relation, it hath to the Equinoctial, the Sphere itself, hath obtained the same Division.  
Secondly, The Horizon is either Rational, or Sensible. The Rational Horizon, is defi●…ed above, and is understood to divide the whole World, or Sphere of the World into two equal parts, the first whereof is called the uppermost Hemisphere, the second the nethermost Hemisphere. It is called Rational, because though we cannot see the whole World, or the exact half of it, yet Reason tell us, by the Rising and Setting of the Sun, Moon, and Stars, that the inferior part of the World, is equal to the superior part. The Sensible Horizon, is nothing else, but so much of the Earth, as a man, by turning his eye once, doth behold round about him.  
The Uses of the Horizon are these. First, it divides that part of the Heavens, which is seen, from the other which is not seen, the Superior part from the Inferior part. 2. Thorough the Poles of the Horizon the Meridian ought to pass: therefore the Description of the Meridian's depend from the Horizon. 3. By the Situation of the Horizon, we know whether it be a Right Sphere▪ Oblique Sphere, or a Parallel Sphere. 4. In the Horizon, the Rising or Setting of the Stars are observed 5. The Horizon showeth, what Degree of the Ecliptic, what part also of the Equinoctial, or what Degree, with any given point of the Heaven riseth or setteth. 6. It boundeth and terminats the Ascensional Difference. 7. Upon the Horizon is numbered, the Rising or Setting Amplitude, of any point in the Heaven. 8. It demonstrats, and showeth the Cause and Reason of the equality of Days and Nights in a Right Sphere, and of the unequality of the same in an Oblique Sphere. For the Horizon in a Right Sphere cutteth all the Circles of the Natural Day equally, but unequally in an Oblique Sphere. 9 From the Horizon we number the Morning-Twilight: for when the Sun ●…s distant, in some Vertical Circle 18 or 19 degrees from the Horizon, so that ●…rom that Moment, he approach nearer ●…nd nearer unto it, then begins the Morning-Twilight. But the Evening-Twilight ends, when the Sun after his Set●…ing comes to that 18 or 19 Degree ●…oresaid; for than doth the Light turn ●…nto Darkness. 10. From the Horizon, we number the Elevation of the Pole, ●…nd Equinoctial. 11. From the Hori●…on are numbered various and divers ●…inds of Hours, as the Italic, and jewish Nocturnal Hours from the West part of the Horizon: but the Babylonish Hours, ●…nd the jewish unequal Diurnal Hours, ●…rom the East part.   

CHAP. VI Of the Meridian.  
THe Meridian is one of the greatest Circles in the Sphere, passing thorough the Poles of the World, and the Poles of the Horizon. By the words, thorough the Poles of the Horizon, it is distinguished from the Horary Circles, of which none but itself, passes thorough the Poles of the Horizon. It has acquired divers and sundry Names, by reason of its manifold uses, by Astrologers, which are not fit to repeat now. What was said above concerning the Colours, and Circles of Declination, to wit, that they are in number equal to the Vertical Points, the same may be said of the Meridian, for as many of them may be imagined, as there are Vertical Points, which are infinite, providing a man travel from East to West: for if a man go from North to South, or from South to North, he travels round about the World, without variation of his Meridian. The Brazen Meridian in the Celestial, or Terrestrial Globe, supplies the office of them all, which are innumerable. But in Geographical Tables, and Maps, Geographers use to extend one Meridian, thorough two, and two opposite Degrees of the Equinoctial, for finding out, the more easily the Latitudes of Places. Of all these Meridian's there is a common beginning se●…led in the Fortunate, or Canary Islands, because the Ancient Geographers deemed those Islands to be the Westmost part of the World, and therefore they fixed their first March-stone there, whence they begin to reckon. But the later Geographers, have removed this March-stone 10 Degrees more Westerly, and have made the common beginning of the Meridian to pass thorough one of the Islands called Osores, whence they begin to reckon from West to East, imita●…ing the order of the 12 Signs.  
The uses of the Meridian are these, 1. It distinguisheth the Eastern part, of the World, from the Western part, the Anterior part, from the Posterior part. 2. It lets us know the South part of the World, and the North part. For when the Sun is in the Meridian, ●…en is Midday, and when the Sun is in the Northern part, of the Meridian, then is Midnight. 3. It divides the Nocturnal and Diurnal Time into two halfs: that is, when the Sun is come to the Meridian in our Hemisphere, as much of the day is past, as what is to come: and when the Sun is come to the Northern part of the Meridian, as much of the Night is past, as what is to come. 4. The Meridian supplies in every Oblique Sphere the place of the Right Horizon: therefore, as the Stars do ascend above the Right Horizon, so they pass over the Meridian, and those ●…ransitions are called the Right Ascensions of the Middle Heaven. 5. From the Meridian, Astronomers begin their Time. 6. In the Meridian, we find out the Zenith; therefore when the Stars come to it, they are either highest above the Horizon, and are said by Astrologers to culminate, or they are in the lowest, and opposite part of it, which is the Nadir. 7. In the Meridian, we find out the distances between the Tropics, and the whole Obliquity of the Ecliptic. 8. Upon the Meridian, we number the Latitude of Places upon the Earth, and likewise the Elevation of the Pole, and Equinoctial. The Elevation of the Pole, is defined, an Arch of the Meridian, measured between the Horizon, and the apparent Pole of the World, which may be found out, after the following manner. Observe the greatest and least Altitude of any of the Stars, which do not set. Subtract the least Altitude from the greatest, and divide the difference. This difference being subtracted from the greatest Elevation, or added to the least, gives the true height of the Pole. December 17. 1669, I observed with a large Quadrant, half 9 a Clock at night, the foremost Guard-star, when it was in the Meridian, and lowest, to have 41 Degrees, 22 minutes of Altitude. And on january 7. 1670, at 7 a Clock in the Morning, I found it, when it was in the Meridian, and highest, to have 70 Degrees, 27 Minute's. I subtract 41 Degrees, 22 Minuts, from 70 Degrees, 27 Minuts, and the difference is 29 Degrees, 5 Minute's. Divide this, and you have 14 Degrees, 32 Minuts, and 30 Seconds. This being added to 41 Degrees, 22 minutes, gives you 55 Degrees, 54 minutes, 30 Seconds. Or subtract 14 Degrees, 32 minutes, and 30 Seconds, from 70 Degrees, 27 minutes, and there remains 55 Degrees, 54 minutes, and 30 Seconds, for our height of the Pole at Edinburgh. 9 The Meridian's do terminate, and bound the Longitudes of Places, as well in the Terrestrial Globe, as in the Maps, and Cards projected in Plano. 10. The Meridian's do terminate, and bound the Breadths and Latitudes of the Zones, and also of the Climates. 11. We find out in the Meridian, the Antipodes, the Anteci, and Perieci.   

CHAP. VII. Of the Tropics.  
THe Tropics are lesser Movable Circles of the Sphere, described from the Solsticial Points, by the mo●…ion of the Primum Mobile. They are called Lesser, because there are in the Sphere Greater Circles, than they are. They are called Movable, that they may be distinguished chiefly, from the Paral●…els of their Horizon (called Almican●…ars), who live under the Poles; and ●…rom the ancient Polars of those, who ●…ive under the Polars, with whom the Tropics are equal to those Circles, which comprehend the Stars, which never come above the Horizon, nor ever go under it.  
They are two in number, to wit, the Tropic of Cancer, and the Tropic of Capricorn. The Tropic of Cancer, is a lesser movable Circle, described from the Summer-Solstitial-Point of the Ecliptic, by the motion of the Primum Mobile. The Tropic of Capricorn, is lesser movable Circle, described fro●… the Winter-Solstitial-Point of the Ecliptic, by the motion of the Primum Mobile.  
The uses of the Tropics are these 1. They demonstrate to us, in the Ecliptic, the two Tropical or Solstic Points, to wit, the beginning of Cancer, and the beginning of Capricorn 2. They terminate and bond, the Sun greatest Declination, and consequently the greatest Obliquity of the Ecliptic 3. When the Sun comes to either of th●… two Tropics, he is either nearest t●… our Vertical-Point, or furthest removed from it. 4. In an Oblique Sphere, they lie Parallel to the longest, and shortes●… Day. 5. Between the Tropics, i●… comprehended the Torrid Zone, as well in the Heavens, as in the Earth: and by the same Tropics, the Torrid Zone is divided from the Temperate Zones.   

CHAP. VIII. Of the Polars.  
THe Polars are lesser Circles of the Sphere, movable, described from the Poles of the Ecliptic, by the motion of the Primum Mobile. For this cause, they are called the Polar Circles. They are two in number, the Polar Arctic, and the Polar Antarctic. The Polar Arctic is a lesser Circle of the Sphere, movable, described from the North Pole of the Ecliptic, by the Motion of the Primum Mobile. The Polar Antarctic, is a lesser Circle of the Sphere, movable, described from the South Pole of the Ecliptic, by the motion of the Primum Mobile.  
They let us see first, the Poles of the Zodiac, and they measure their distance from the Poles of the World. 2. They bound the Temperate Zones, and separats them from the Cold Zones, which are bounded and enclosed by their circumferences. It is to be observed, that the ancient Astronomers, Proclus, Cleomedes, and the rest, had not the same description of the Polars, which we have. For the Ancients, did not describe them, as passing thorough the Poles of the Ecliptic, but thorough the common Sections of the Meridian, and Horizon, equidistant to the Equinoctial▪ and therefore, so much was their distance from the Poles of the World, a●… the height of the Pole was above the Horizon. And by this means, where there is no Elevation of the Pole, as in a Right Sphere, there are no Polars. But from thence, they are more, and more gradually augmented, and enlarged, according to the increment of the Poles Elevation.  
The uses of the Polars, according to the Ancients, are these, 1. They comprehend the Arch of the Elevation of the Pole. 2. Of all the Parallels of the Equinoctial, which are always seen above the Horizon, they are the greatest and of all the Parallels of the Equinoctial, which lie hid under the Horizon, they are the greatest also. But contra●…iwise, of all the Parallels of the Equinoctial, which arise and set in twenty four Hours, they are the least. Therefore (3.) the foresaid Polars, comprehend within their Compass, and Circle, ●…he whole Stars and Points of Heaven, which are always in sight, and do not ●…et. Hence, there ariseth a threefold ●…istinction of the Stars. 1. There are ●…ome, which have a perpetual Day, and ●…ever set, or fall under the Horizon, to ●…it, those which are comprehended within the Circle of the Polar Arctic. 2. There are others, which have a perpetual Night, which never rise, or come ●…p above the Horizon, to wit all those, which are included within the Circle of ●…he Polar Antarctic. There are (3.) others which both rise and set in four ●…nd twenty Hours, to wit those, which ●…ither on this side, or that side of the Equinoctial, tend towards and come nearest to the foresaid Polars.   

CHAP. IX. Concerning other Circles of the Sphere, both greater and lesser, which cannot be conveniently drawn upon it.  
BEside the Circles of the Sphere hitherto explained, there are yet innumerable more, both of the greatest and lesser sort, which Astronomers have excogitated for attaining a more perfect knowledge of the Heavenly Motions▪ 1. There are of the greatest sort Verticals, which pass thorough every point o● the Horizon, cutting one another there which by the Arabians are called Azimuths. 2. There are the Horary Circles, which divide the Heavens, into four and twenty parts, which are o● three sorts. For either they have the beginning in the Meridian, and pa●● thorough the Poles of the World, or the have their beginning in the East, o● West-part of the Horizon, by whic● means they touch lightly, the two Circles lying parallel to the Equinoctial, of which one is the greatest of all, which are always seen above the Horizon, the other the greatest of all, which are not seen above the Horizon: or lastly, they have their beginning in the Horizon, but neither go thorough the Poles, of the World, nor go near to the foresaid Parallels, but divide all the Segments of the Parallels, which are above or below the Horizon, into twelve equal parts. 3. There are Circles of Declination, which pass thorough the Poles of the World, and every point of the Equinoctial. There are 4. Circles of Latitude, which pass thorough the Poles of the Ecliptic, and every one of his Degrees.  
The lesser Circles are infinite also; for there is no great Circle, which hath not his own Parallels. As first the Horizon, which hath Circles of Altitude, called by the Arabians Almicanthars. The Equinoctial, hath its own Parallels, to wit, described by the Primum Mobile, from all, and whatsoever Points are in the Heavens. So hath the Zodiac his Parallels, described about the Poles of the Ecliptic, which Parallels every Star, or point of the Heavens, according to the proper motion of the eight Sphere, do describe, and many more are there invented by Astronomers for Astronomical uses.   

CHAP. X. Of the Zones.  
TO the Doctrine of the Sphere, is commonly annexed the Geographical Tractat of the Zones. The Zones therefore are nothing else, but as much bounds, of the Heaven, or of the Earth, as is comprehended between both the Tropics, or between either of the two Tropics, and the next Polar, or between either of the two Polars, and the neighbouring Pole. Therefore the Zones, are either Celestial, or Terrestrial. The Celestial Zones, are bounded by themselves, and their own Circles in the Heavens. The Terrestrial Zones, lie directly under the same places of the Heavens. They are five in number, one Torrid, two Temperate, and two Frigid. The Torrid Zone, is that space of the Heavens, or the Earth, comprehended between the two Tropics. This is divided into two parts, of which one is called the Northern, the other the Southern part. It is called Torrid, because here, the Rays of the Sun are more perpendicular, and so hotter, that the Inhabitants are in a manner scorched, and burnt up with Heat. The Temperate Zones, are that space of the Heavens, or of the Earth, comprehended between either of the two Tropics, and the neighbouring Polars: and that which is included, between the Tropic of Cancer, and the Polar Arctic, is called the Temperate Northern Zone, wherein are contained, all Europe almost, and a great part of Asia, and also a part of America. But that which is included between the Tropic of Capricorn, and the Antarctic Polar, is called the Southern Temperate Zone. This contains more Sea, and less Land. They are called Temperate, because the Rays of the Sun, being more oblique, there is not such a reflection of Heat, but offer a most commodious Dwelling to the Inhabitants. The Frigid Zones, are that space of the Heavens, and of the Earth, comprehended between either of the Polars, and the neighbouring Pole of the World. And that bounds, which is included between the Polar Arctic, and the North Pole, is called the Northern Frigid Zone: and that bounds which is included, between the Polar Antarctic, and the South Pole, is called, the Southern Frigid Zone. They are called Frigid, because the Rays of the Sun are most Oblique, and are absent almost half a Year; so that all things become rigid and stiff, with Frost, Ice, and Snow. In this Zone, lies Island and Greenland, but in the Southern cold Zone, the parts are unknown to us.  
The Inhabitants of the five Zones, have obtained divers names. For those, who inhabit the Torrid Zone, are called Amphiscii, as having a shadow on both sides. I say on both sides, in respect of the Vertical Point. For the Sun with them, is sometimes on this side, and sometimes on that side of their Vertical Point: sometimes the shadow of their Dial's is projected from South to North, and sometimes from North to South, when he is in the Meridian. The Inhabitants of the Temperate Zones, are called Heteroscii, as having but one shadow. For at 12 a Clock in the Day, the shadow is either casten towards the North, as with us, or towards the South, as with those, who dwell in the Southern Temperate Zone. But those, who live in the Frigid Zones, are called Periscii, as having a shadow, which goes round about them; because they have the Sun for several Months of the Year, above their Horizon, and the Heavens there, like a Millstone, is whirled about, so that the Sun and Stars describe Parallels to the Horizon, and therefore in four and twenty Hours, he runs about without rising and setting, and projects his shadow into an Orb, or Circle.  
There are likewise, the Antipodes, Anteci, and Perieci. Antipodes, are those, who have the same Meridian, but dwell in points of it, diametraliter opposite, and are under opposite Parallels, (to wit in an oblique Sphere,) of which the one is Southern, the other Northern. These following Phenomena, are proper to them. 1. Though they have the same Rational Horizon, yet beholding the opposite Faces, all things fall out to them chose. For when we have Day and Midday, our Antipodes have Night and Midnight. When we have Summer, they have Winter. When the Sun rises to us, he sets to them. We have North Latitude, they have South Latitude.  
The Anteci are those, who dwell under opposite Parallels, equally distant from the Equator, towards both the Poles, under the same Meridian, but not in Points diametraliter opposed, but in a Semi circle of the Meridian intercepted between the Poles. They have these Phenomena proper to them. First, They agree in the same Longitude, and Latitude; for how much is the South Pole elevated to those, so much is the North Pole elevated to these. 2. In the same Moment of Time, both of them have the Sun in their Meridian. But in this they differ; while the Sun is coming to the Tropic of Cancer, those have Summer and longer Days, but these have Winter, and shorter Days. Again, when the Sun is returning, those have Harvest, the Days Decreasing, but these have the Spring, the Days Increasing. Hence it is, that the Sun doth not rise, and set to both, at the same time.  
The Perieci are those, who dwell under the same Parallel and Meridian, but in Points of the same Parallel diametraliter opposite; so that both of them behold the same Pole, with equal height above the Horizon. First, They dwell in the same Zone. Secondly, They have the same Elevation of the same Pole. They have the same Winter, the same Summer, the same longest Day, and the same increment, and decrement of the Natural Days. But here they differ; those having the Sun rising, these have it setting; those having the Sun in the Meridian, these have it at our Midnight: and chose, when to those the Sun is setting, to these he is rising, when to those it is Midnight, to these it is the Meridian.   

CHAP. XI. Of the Rising and Setting of the Stars according to the Poets.  
HItherto we have treated of the Hypotheses, to wit, the Circles of the Sphere, which so much conduce for explaining the Phenomena of the Primum Mobile. It now remaineth, that we speak and treat of the thing itself, to wit, the Phenomena themselves. And in the entry, we ought to have spoken of the rising and setting of the Stars, called Ortus & occasus stellarum Astronomicus; but the knowledge of those things, cannot be taught here compendiously, nor without the Science of Spherical Trigonometry; therefore passing this, we come to explain the rising and setting of the Stars, called Ortus & occasus Poeticus, which is the second Phenomenon of the Primum Mobile.  
This rising and setting of the Stars according to the Poets, is nothing else, but the rising of a Star above the Horizon, and the setting of a Star under it, in relation to the various Position of it, with the Sun. It is called Poetical, not because it doth not belong to Astronomers; for it is a part of their Science to determine those Risings and Setting, but because the Poets in describing certain Seasons of the Year, use this method, as will be seen afterward.  
Of this Poetical Rising and Setting, there are three forms. First, That which is called the Rising and Setting of a Star Cosmice. Secondly, That which is called the Rising and Setting of a Star, Acronyce. Thirdly, That which is called the Rising and Setting of a Star Heliace. Each one of those hath a double signification; one general, the other special. The Rising of a Star Cosmice generally taken, is the Rising of a Star above the Horizon, falling out from the Rising of the Sun to his Setting. The Setting of a Star Cosmice, generally taken, is the Setting of a Star, falling out from his Rising to his Setting. The Rising of a Star Acronyce, generally taken, is the Rising of a Star above the Horizon, falling out the whole time, the Sun is under the Horizon. The Setting of a Star Acronyce generally taken, is the Setting of a Star under the Horizon, falling out all the time the Sun is under the Horizon. The Rising of a Star Heliace generally taken, is the appearing of a Star after the Sun is Risen. The Setting of a Star Heliace generally taken, is the disappearing of a Star, after the Sun is set. But their special signification denotes, and determines, a certain, and definite time. Therefore, the Rising of a Star Cosmice, is the ascending of a Star above the Horizon, in the same moment, wherein the Sun Rises. The Setting of a Star Cosmice, is when a Star goes down, while the Sun is Rising. The Rising of a Star Acronyce, is when a Star comes above the Horizon, the Sun going down under the Horizon that same moment. The Setting of a Star Acronyce, is when a Star Sets with the Sun, that same moment. The Rising of a Star Heliace, is when a Star, which could not be seen, by reason of its nearness to the Sun, is now seen in the night time. The Setting of a Star Heliace, is when a Star, by reason of the Sun's great distance from it, might have been seen in the night time, but the Sun coming nearer to it, it disappears out of our sight.  
We have an Example of the Rising of a Star Cosmice, in the first Book of the Georgics.  
Vere fabis satio: tunc te quoque Medica putres  
Accipiunt sulci, & Milio venit annua cura  
Candidus auratis aperit, cum Cornibus annum  
Taurus, & adverso cedens Canis occidit Astro.  
When Taurus with his gilded Horns,  
Begins the Year, then Sow your Corns  
Sow Millet-seed, an yearly toil,  
Sow Claver-grass, in putrid soil,  
Sow yearly Pulse, and what you please  
Sow in the Spring, both Beans and Pease.  
Virgil doth express here the Spring time, when the Millet-seed is to be sown●… which is in the beginning of April: An●… seeing the Sun at that time, is about th●… end of Aries, it must be understood of the Rising of Taurus, which at that time riseth with the Sun Cosmice. At this time the Romans used to sow their Beans, their Claver-grass, and their Millet, which every year must be renewed; whereas the Claver-grass is to be sown but once in ten years.  
We have likewise an Example of the Setting of a Star Cosmice, from that same place in Virgil.  
Ante tibi Eoae Atlantides abseondantur  
Gnosiaque ardentis decedat stella Coronae  
Debita quam sulcis committas semina.  
When Pleiades, the Maidens seven,  
Are set into the Western-Heaven,  
When Ariadne's Crown full bright  
Before the Sun comes in our sight,  
Then sow your Ground with Wheat and Rye  
'Tis of October eighteen day.  
Before you sow your Ground (says he) let the Pleyades, or Seven-stars be set, which about October 18, go down in the West, in the same Moment of Time, while the Sun is Rising in the East, which is called Occasus Cosmicus.  
We have an Example of the Rising of a Star Acronyce, from Ovid, in his first Book de Ponto.  Quatuor autumnos Pleias orta facit. 
Four Harvests surely there have been,  
For Pleias four times have been seen.  
Ovid is here speaking of the Harvest time, when the Sun is in Scorpio, therefore when the Sun is Setting, Taurus or the Bull, and the Pleyades are Rising Acronyce.  
We have also an Example of the Setting of a Star Acronyce, from the same Ovid, in his second Book of his Fasts.  
Illa nocte aliquis tollens ad sidera vultus  
Dicet ubi est hodie, quae Lyra fulsit heri.  
Last Night when I surveyed the Sky,  
saw the Harp, 'tis gone away  
This Night.  
This time, is the second day of Fe●…uary, at which time the Constellation ●…lled the Harp, sets Acronyce, with the ●…u.  
We have likewise an Example of the Rising of a Star Heliace, from the first Book of the Georgics.  Gnosiaque ardentis decedat stella Coronae. 
When Ariadne's Crown full bright  
Before the Sun comes in our sight.  
'Tis eviden●… that Virgil speaks here of the Rising of this Constellation Heliace, called Aridnes Crown, when the Sun is in the beginning of Scorpio. For seeing this Constellation rises at Rome, where Virgil lived, with the 27 Degree of Virgo, it is needful to conceive this Crown to be seen in the Morning, the Sun being yet under the Horizon.  
Note, That there is a Figure called Hypallage in the word Decedat: for the Crown doth not recede from the Sun, but the Sun from it.  
And lastly, We have an Example of the Setting of a Star Heliace, from the same place of Virgil.  Taurus, & adverso cedens Canis occidit Astro. 
And when the Dog shall disappear,  
By Phoebus' Beams him coming near.  
The Poet is here speaking of the Sun's ingress into Taurus, which fell out in Virgil's time on the 1●… of April. But seeing the Dog-star sets at Rome with the 22 Degree of Taurus, therefore, the Sun setting in the Evening, the Dog-star setteth Heliace, or disappears out of our sight, by reason of the Sun's Rays, which now are nearer him.  
Observe, That what Stars do arise Cosmice, which is also called Ortus Matutinus, they set Acronyce, which is called Occasus Vespertinus: and what Stars do arise Acronyce, which is called Ortus Vespertinus, they set Cosmice, which is called Occasus Matutinus, according to the following Rhyme.  
Cosmice descendit signum, quod Chronice surgit,  
Chronice descendit signum, quod Cosmice surgit.  
Aliter.  
Mane vehit supra terram tibi Cosmicus ortus  
Sidera, sed Phoebi lumine tecta latent.  
Mane dat Heliacus quaedam subvecta videre  
Astra, sed Achronycus nocte videnda trahit.  
Note secondly, That the word Cosmicus, comes from Kosmos, the World. That the word Chronicus, comes from the Greek word Chronos, Time. But Acronycus comes from Acra & Nux, which is the first part of the Night, or the Evening▪ Twilight. That Heliacus comes from Helios, the Sun. Lastly, That Chronice, and Acronyce have the same signification.   

CHAP. XII. Concerning the Natural, and Artificial Days.  
NOw follows another Phenomenon of the Primum Mobile, to wit, the Doctrine of Days Natural and Artificial. Days are twofold, Astronomical, and Civil. Astronomical Days, are such as are measured, by the Revolutions of the Equinoctial, and determined by a certain quantity. Days Civil, are such as every Nation, according to their own Custom make use of. The Astronomical Day, is either Natural, or Artificial. The Natural Astronomical Day, is a space of time, wherein the Sun, by the Motion of the Primum Mobile, being carried about, from whatsoever immovable point of the Heavens, returns to that same point again. These Astronomical Days have their beginning in the Meridian, as was insinuate before. The Artificial Astronomical Day, is a Space of Time, wherein the Centre of the Sun remains above the Horizon. And the Artificial Night, is as much Time, as the Centre of the Sun remains under the Horizon.  
The Doctrine of the Artificial Days and Nights, is contained in the following Theorems. 1. The Artificial Days and Nights, with the Amphiscii, Heteroscii, and partly with the Periscii, are parts of the Natural Day: but with the Periscii, in those parts of the Earth, wherein the Sun, by the going about of the Primum Mobile, perfects some Circumgyrations, either above the Horizon, without setting, or under the Horizon, without rising, one Artificial Day, or one Artificial Night, doth excresce into many Natural Days; so that indeed under the Poles, the Artificial Day contains half a Year, and the Artificial Night as much; and so to speak properly, the whole Year consists but of one Day, men looking to the Analogy of the Natural Day. 2. Under a Right Sphere, the Artificial Day, is equal to the Night: for the Horizon, in this Position of the Sphere, cuts the Circuli Dierum, the Day-Circles, into two equal parts. The Day-Circles, are called those Parallels of the Equator which the Sun doth daily describe, by the Motion of the Primum Mobile. 3. In an Oblique Sphere, there are only twice a Year, two Equinoxes, when the Sun is in the beginning of Aries and Libra. The Reason of this appears, from the mutual Section of the Horizon, with the Circuli Dierum, or Day-Circles, which is indeed unequal, except when the Sun is in the Equinoctial. 4. In an Oblique Sphere, which hath the vicissitude of the Artificial, and Natural Day, by one Revolution of the Equator, the Sun being in the. Tropic of Cancer (we are now speaking of this uppermost part of the Sphere) we have the longest Day in all the Year, and the shortest Night: but the Sun being in the Winter Solstice, the Day is shortest, and the Night longest. 5. In the same Position of the Sphere, thorough the whole half of the Ecliptic descending, the Sun maketh the following Days shorter, than the Days going before, but the Nights longer. But in the half of the Ecliptic ascending, the Sun maketh the Days following longer, than the Days going before, but the Night's shorter. 6. When the Sun is existing, in places of the Ecliptic, equally distant, from the same Solstitial Point, Days are equal to Days, and Nights to Nights. 7. When the Sun is existing in places of the Ecliptic equally distant, from the same Equinoctial Point, the Day of one Place, is equal to the Night of another. 8. In an Oblique Position of the Sphere, the greater the Elevation of the Pole is, the greater are the increments of the longest Day, and shortest Night, until coming under the Polars, the longest Day contains twenty and four Hours. 9 In an Oblique Sphere, of such as dwell between the Polar, and next Pole, the longest Day excresceth into many Natural Days, as also the longest Night. But there are certain intermediat Horary Circles, a part of which is above the Horizon, and a part under, in which, when the Sun is existing, the Artificial Days, as also the Nights, are▪ parts of the Natural Day. 10. In a Parallel Sphere, such as they have, who live under the Poles, the whole Year, is divided into one Artificial Day, and one Artificial Night.  
The length of every Artificial Day, is known by the Diurnal, and Nocturnal Arch. First, find the Oblique Ascension or Point of the Equinoctial, which riseth with the Sun, and Oblique Descension, or Point of the Equinoctial, which setteth with the Sun. Subtract the lesser from the greater, and half the difference, is the Ascensional difference, which added to six Hours in the Summer half Year, but subtracted therefrom in the Winter half Year, gives half the Diurnal Arch, whose double is the whole Diurnal Arch, and the Compliment of the Diurnal Arch to 24 Hours, is the Nocturnal Arch. For Example, The tenth day of April 1687, the Oblique Ascension of the Sun (being in the first Degree of Taurus) is 10 deg. 21. m. the Oblique Descension is 45 deg. 27 m. whose difference is 35 deg. 6. m. whose half is 17 deg. 33 m. the Ascensional difference, which being added to 90 deg. or 6 Hours, is 107 deg. 33 m. which make 7 hours, 10 m. fere, for the time of the Suns setting, which is always half the Diurnal Arch. Therefore the Diurnal Arch is 14 hours, 20 m. Which taken from 24 hours, there remains 9 hours, 40 m. for the Nocturnal Arch required. Note, That the Ascensional difference added to the Oblique Ascension in the Summer half Year, but subtracted from it, in the Winter half Year, gives the right Ascension of the Sun, or any of the Stars.  
What is said of the Day in respect of the Sun, may be most commodiously applied to the Stars. For the Day of a Star, is rightly called the space of Time, wherein it is above the Horizon: and the Night of a Star, the space of Time, wherein it is below the Horizon. Concerning the days of the fixed Stars, let the following Theorems be observed. 1. In a Right Sphere, the Stars have a perpetual Equinox. 2. But in an Oblique Sphere, the fixed Stars, whose North Declination, is greater than the Compliment of the Altitude of the Pole, are said to have an Eternal Day: but those Stars, whose South Declination, exceeds the Compliment of the Altitude of the Pole, are said to have an Eternal Night. The intermediate Stars, have the course of rising and setting. 3. In a Parallel Sphere, the fixed Stars are said to have Eternal Days, and Eternal Nights.  
Days Civil, are called the space of Time, of one Revolution of the Equinoctial, which according to every Nation, or Country, is divers ways begun, and made use of. For as there are various and divers Nations in the World, so each one hath a different way of beginning their Hours. For the jews, by Divine Institution, began their Day, from the setting of the Sun, which custom the Italians do observe. The Babylonians began their Day from Sun rising, whose practice, the Norinbergers, the People called the Umbri, and the Egyptians do imitate. The Arabians as the Astronomers, begin their Day from the Meridian. The Romans from Midnight. The Germans, the Frenches, and Spainards' begin their Day from the Meridian, and Midnight. For their Clocks, and Watches are so contrived, that they return from one a Clock in the Nighttime, to twelve a Clock in the Daytime, and from one a Clock in the Daytime, to twelve a Clock at Nighttime. Their Days are divided, as the Astronomical Days, into one Artificial Day, and likewise into Forenoon, and Afternoon.  
And because Hours are parts of the Days, therefore we must speak a little of them. The Hour is the twentieth and fourth part of the Natural Day, or the space of Time, wherein the twentieth and fourth part of the Equinoctial, or 15 Degrees thereof, riseth above the Horizon. But this Definition is not sufficient, because it doth not agree to all Hours: for every twelfth part of every Day, and every Night whatsoever, was called by the jews, and the Ancients an Hour. But 15 Degrees of the Equinoctial, do not always ascend above the Horizon, every one of these Hours; but sometimes more, and sometimes fewer, as will appear afterward. Therefore, an Hour may rather be defined thus, a certain part of the Artificial Day, and Night, made use of by divers Nations, after a divers manner, that it may be known generally, what the Hour is. For in effect, that definition agrees only to to those Hours, which are called Hor●… Aequales, equal Hours. The Hours then, which are called unequal, aught to be defined thus. The twelfth part of every Artificial Day and Night: therefore according to the divers Seasons of the Year, the Hours are sometimes shorter, and sometimes longer: in Summer longer, and in Winter shorter, as are th●… jewish Hours: for they divide both the Day, and the Night into twelve parts, both in Summer and in Winter, calling the rising of the Sun, the beginning of the first Hour, and consequently nine their third Hour; twelve their sixth Hour, three a Clock in the Afternoon their ninth Hour, and the setting of the Sun, the end of their twelfth Hour, by which means, their Hours must be far longer in Summer, than in Winter.  
The equal Hours are of three sorts: for some take their beginning from the setting of the Sun, as the Italian Hours. Others take their beginning from the rising of the Sun, as are the Babylonish Hours, and the Hours of the City of Norimberg, who from the rising of the Sun begin the number of the Hours of the Day; the Circles of which Hours do lightly touch the greatest Parallels, of all, which do appear above the Horizon, and of all which do not appear. Lastly, Others do take their beginning from the Meridian, which Astronomers make use of, and these Nations, which either take their beginning of Hours from the superior part of the same Circle, or from the inferior part.   

CHAP. XIII. Concerning Years.  
AS Hours make up Days, so Days make up Years, therefore we must speak somewhat of Years. The Year than is twofold, Astronomical, and Political. The Astronomical Year, is the space of Time, wherein the Sun returns, either to the same Point of the Ecliptic, or to the same fixed Star. And this is twofold, the Tropical Year, called Annus Vertens, or the Syderial Year. Annus Vertens, is a space of Time, wherein the Sun leaving some Point of the Ecliptic, returns again to the same Point. The quantity of this Year is changeable; for sometimes it is more, and sometimes it is less. Between these two extremes, the middle Year contains 365 days, hours 5, m. 49, sec. 15. thirds 46. But the true or apparent Year is sometimes 365 days▪ hours 5, min. 56. sec. 53, thirds 1. Sometime it is 365 days, hours 5, min. 42, sec. 28, thirds 27. The Syderial Year, is a space of Time, wherein the Sun under the Starry Sky, returns to the same fixed Star. The quantity of this Year is 365 days, hours 6, min. 6, sec. 39 It is always equal to itself, and therefore the measure of the Year called Annus Vertens. The beginning of this Annus Vertens, is taken from the Vernal Equinox, but the beginning of the Syderial Year, from the first Star of Aries.  
The Political Year, is an Annual space of Time, which is either accommodated to the course of the Sun, or the Moon, or to both, according to the common reckoning of several Countries and Nations. This Political Year is manifold; for it is either julian, which contains 365 days, hours 6, which six Hours, if they were reckoned every Year, would make confusion: therefore the Masters of Astronomy have appointed, they should be omitted, till the fourth Year, and then four times six, make 24, which make up a full and complete Day, which being inter called, that is, interlaced, or put between, as in Leap Year there is a Day put between the 28 of February, and the first of March, the Year is called Annus Intercalaris, or Bissextile Year. It is to be adverted, that the cause of correcting the julian Calendar, by Pope Gregory the 13, in the year 1582, was the unjust quantity of it. For by this, it came to pass, that after some Ages, the four Cardinal Points did anticipate and prevent their Seats; and so at length the four Seasons of the Year, might be interchanged. From this it is evident this Day, that according to these times, the Equinoctial, and the Ingress of the Sun into the 12 Signs have anticipated almost 13 Degrees. That is, the entering of the Sun, into Aries, Taurus, etc. falleth out sooner by 13 Degrees, than to the Romans: which comes to pass, because more, than what is just, is given to the space of the Year. For there were given to the Year, by the correction of julius Cesar, 365 days, and six hours: for which hours, every fourth year, one day is added, and so the common julian year contains 365 days, but the Bissextile 366. But seeing the Solar year, in which the Sun runs thorough the whole Ecliptic, is less than this space, by almost eleven Minute's of Time every Year; it comes to pass, that in 50 year, and a half, one hour remains, and in the space of 130 years, a whole day remains.  
I said the Political Year, was manifold, either julian, of which hitherto, or Egyptian, or judaical. The Egyptian year contains always 365 days. This Year was esteemed most useful by the ancient Astronomers, for the Art of reckoning the Celestial Motions. The judaical Year is accommodated and fitted to the Motion of the Moon, and contains, for the greatest part, twelve, and sometimes thirteen Lunations. This Year did the Astronomers use, before the reformation of the Calendar, instituted by julius Cesar, by the help of one Sosigenes, a famous and learned Mathematician. The beginning of these Years is divers also. For the ancient Romans, began their Year from March: the later Romans from the midst of Winter, called Bruma. The jews, by Divine Institution, began their Year from the New Moon, which was next after to the Vernal Equinox. That we this day begin our Year from the first of january, it is for this, because we following the custom of the late Romans, beginning their Year from the midst of Winter, which was nearest to the first of january, by little and little the Winter Solstice did prevent, and anticipat its Seat, and Place. The Egyptian year, hath not a sure beginning, by reason that six hours are omitted. Hence is it, that every fourth Year it anticipats one Day: and therefore within 365 Years, four times numbered, or 1460 julian Years, the beginning of the Egyptian Year, wanders over all the Days of the julian Year.   

CHAP. XIV. Concerning the divers Phenomena, which are to be seen in the various Positions of the Sphere.  
THe last part of this little Tractat, shall be in examining the Phenomena, which are proper to the various Situations, and Positions of the Sphere. The Sphere may have seven different Positions, 1. When both the Poles of the World do rest in the Horizon, which is called a Right Sphere. The second Position is Oblique, when our Vertical Point, is terminated between the Equinoctial, and either of the Tropics. The third Position is, when our Zenith is under either of the Tropics. The fourth is, when our Zenith is between either of the Tropics, and the neighbouring Polar. The fifth is, when our Zenith is in the very Polar itself. The sixth is, when our Zenith is between either of the Polars, and the neighbouring Pole of the World. And lastly, when the Poles of the World, do fall in with the Poles of the Horizon, which is called a Parallel Sphere.   

CHAP. XV. Concerning the Phenomena of the first Position.  
1. EVery Star in the Heavens riseth and setteth, neither is there one of them, without this property: and therefore in this Position, there is neither Polar Arctic, nor Antarctic, according to the Ancients. 2. There is here a perpetual Equinox. 3. The Sun every Year passing twice over their Heads, is to them twice Vertical, to wit, when he is in the Equinoctial Points. 4. As much, as the Sun declines from their Vertical Point, towards the North, as much also doth he decline from their Vertical Point, towards the South. 5. They have four Solstices, two when the Sun is highest in their Vertical Point, and two, when he is lowest, in Cancer, and Capricorn. 6. They have two Summers and two Winters, but only Analogically: for even in Winter, their Bodies are scorched with heat. 7. There are here in this Position, five different Shadows, the Meridional, or South Shadow, the North Shadow, a Shadow from the East, a Shadow from the West, and a perpendicular Shadow, which falls out only, when the Sun is in the Equinoctial Points. 8. The end or extremity of their Gnomon, upon their Horizontal dials, which are our Polar dials, describe the whole Year, the Figure called Hyperbole, except when the Sun, is in the beginning of Aries and Libra, where he describes a strait and right Line.   

CHAP. XVI. Of the Phenomena of the second Position▪  
1. SOme Northern Stars tarrying always above our Horizon, have Eternal Days; and chose, there are some about the South Pole, which never come above the Horizon, but have Eternal Nights. 2. The Arctic, and Antarctic Circles, according to the Ancients, are not as yet equal to our Polars. 3. The Artificial Day is not equal to its own Night, two Days only excepted, when the Sun is in the Equinoctial Points, at which time, there is thorough the whole World an Equinox. 4. The longest Day there, doth not exceed thirteen Hours and a half. 5. The Sun is to them, twice Vertical every Year, to wit, when he comes to those Degrees of the Ecliptic, whose Declination, is equal to the Latitude of the Place; for he describes then, a Parallel thorough the Zenith. 6. The Sun in the Meridian, goeth further towards the South, than towards the North. Note, That we are now speaking, and in the following Discourse, of those seven Positions, which are in the Northern Sphere. 7. There are here, four Solstices, two high, and two low. The two highest fall out, when the Sun is in that Parallel, which passeth thorough the Zenith. The two lowest are, when the Sun is in the Tropics. Yet that which falls out in the Tropic of Capricorn, is lower, than that which falls out in the Tropic of Cancer. 8. They have two Summers, and two Winters, but unequal, as appears from the various Situation of the Parallels. 9 The longest Day is not, when the Sun is in the highest Solstices, but in the Tropic of Cancer. 10. There are five different Shadows, as we observed in the first Position. 11. The end or extremity of the Gnomon, by its Shadow, when the Sun is out of the Equinoctial, describes (as in the first Position) the Figure called Hyperbole, but the opposite sides are not equal as there, but unequal. 12. In any part of this Position, where the Elevation of the Pole, is less, than the Declination of the Sun, the Shadow of a Style perpendicularly erected upon a Plain, may have a natural, visible, Retrocession. In the matter of Ahaz his Dial, the Retrogradation of the Shadow was miraculous, because it was done without, and not within the Tropics, neither is it possible in nature, it can happen, but where the Elevation of the Pole, is less than the Sun's Declination, which is only within the Tropics. But the foresaid Dial was placed far without, to wit, under the Latitude of 35 Degrees.   

CHAP. XVII. Of the Phenomena of the third Position.  
1. ALL the Stars, which are comprehended within the North Polar, remain always above the Horizon, neither do they ever set, unless it be, by a general setting Heliace: and chose, all the Stars, which are comprehended within the South Polar, have a perpetual Night▪ therefore the Polars, according to the Ancients, are now equal to our Polars. 2. The longest Artificial Day is, when the Sun passeth over our Zenith; the shortest, when the Sun is farthest in the Meridian removed from it. 3. Once a Year only is the Sun Vertical, to wit, when he is in the beginning of Cancer. 4. The Sun in the Meridian, never descendeth from the Zenith towards the North, but returning from the Tropic of Cancer, he is always in the South. 5. There are here, but two Solstices, one high, another low. The highest, when the Sun is in the Tropic of Cancer; the lowest when the Sun is in the Tropic of Capricorn. 6. The Day is longest, when the Sun is in the Tropic of Cancer, it is shortest when the Sun is in the Tropic of Capricorn. 7. There is one Summer, when the Sun is in the Zenith, and one Winter, when he is in the Winter Solstice. 8. They have four different Shadows, one Perpendicular, one Oriental, one Occidental, and one Meridional. Here begin the Heteroscii, for the Meridional Shadows begin there to decay, that is, the Shadows projected towards the South. 9 The extremity or end of their Gnomon, upon their Dial's, describe also the Figure called Hyperbole, the sides opposite being unequal.   

CHAP. XVIII. Of the Phenomena of the fourth Position.  
AS the Arctic and Antarctic of the Ancients, are greater than our Polars, so there are more Stars in this Position of the Sphere, seen perpetually, and more perpetually lurking under the Horizon, than in the last Position. 2. The unequality of Days and Nights, are also augmented. The Artificial Day is at the longest, when the Sun comes nearest to our Zenith, and at the shortest, when he is furthest removed from it: and as the shortest Artificial Day cannot be less, than 13 Hours and a half, so the longest Day cannot be 24 Hours. This least Artificial Day, is truly the longest Day, our Vertical Point coming nearest to the Tropic. It is called the least Artificial Day, because it is the shortest of all the longest Days, which can arise from the variation of the Vertical Point, between the Tropic and the Polar: and therefore, itis not called Minimums the least, in respect of the rest of the days of the same Elevation of the Pole, but in respect of the rest of the longest Days, which may be found between the Tropic and Polar. The longest Day in this fourth Position of the Sphere, the Zenith coming nearest to our Tropic, cannot be less, than 13 Hours and a half, as the longest Day cannot contain 24 Hours. For this comes to pass, when the Zenith is in the Polar: therefore we must read, as the shortest Artificial longest Day, cannot be less, than 13 Hours and a half, etc. 3. The Sun can never come to their Zenith, neither can he ever touch lightly (stringere) their Horizon, when he is in the Meridian. 4. There are two Solstices, one when the Sun is in Cancer, and highest, another lowest, when he is in the Tropic of Capricorn. 5. There is one Summer, and one Winter. 6. There are only three different Shadows, one Oriental, the second Occidental, and the third Northern. 7. The extremity or end of their Gnomon, fixed upon the Ground perpendicularly, describe as yet Hyperboles.   

CHAP. XIX. Of the Phenomena of the fifth Position.  
ALL the Stars, whose distance from the Equinoctial, is greater than the Obliquity of the Ecliptic, either do not set under the Horizon, if they be Northern Stars, and do not rise above the Horizon, if they be Southern Stars: Therefore the Arctic, and Antarctic of the Ancients are equal to the Tropics. 2. The longest Day contains 24 Hours, and then there is no Night: and chose, the longest Night consists of twenty and four Hours, and the Artificial shortest Day is nothing. 3. The Sun every year toucheth lightly the border of the Horizon twice, without rising and setting, namely when he is in the Tropics. 4. The Sun at twelve a Clock in the Day, is always South, nevertheless, when he is in the Tropic of Cancer, the half of his Body may be seen in the North, at 12 a Clock at Night. 5. There are here two Solstices, one high in Cancer, the other low in Capricorn. But according to the similitude of Solstices, which are in other Zones, we may say there are three Solstices there, one high in Cancer, when the Sun is high in the Meridian, to wit, 47 Degrees above the Horizon, which is the distance of the Tropics; there are two lower, of which one is in the same Tropic of Cancer towards the North, when he toucheth lightly the border of the Horizon, the other in the Tropic of Capricorn, where he also lightly toucheth the border of the Horizon. 6. There is one Summer, and one Winter. 7. There are four different Shadows; one Eastern, one Western, one Northern, and one Southern; though this happens but once a Year, the Sun shineing with the half only of his Rays, which makes the light more obscure and dark, than when he shines with his full Rays. Here begin the Heteroscii. 8. The extremity or ends of the Gnomon, describe the Figure called Parabola, upon the Horizontal Dial's, but an Hyperbole, so soon, as the Sun is gone from the Equinoctial, whereas on all other Plains, he describes always strait and right Lines.   

CHAP. XX. Of the Phenomena of the sixth Position.  
THere are very few Stars, which can rise or set, to wit, those only, whose Declination is less than the distance of the Tropics; because the Arctic, and Antarctic Circles, comprehending within them, the Stars which do set, and do not set, are greater than the Tropics. 2. They have an Equinoctial, as other parts of the Earth. But when the Sun is in that Parallel whose Declination from the Equinoctial, is equal to the distance of the Poles of the World from the Zenith, the Day is twenty and four Hours, and the Artificial Day excresceth, and shoots out, into many Natural Days. 3. The Sun being in the same Parallel, he lightly toucheth, the border of the Horizon, and coming to it, she shines only with an half Orb. 4. They have but only one Solstice, in the Tropic of Cancer; for the other in the Tropic of Capricorn cannot be seen. But Analogically, and ●…n similitude there are six Solstices. Two high, when the Sun is in the Tropic of Cancer: for there, as well to the ●…outh, as to the North, the height of ●…he Sun in the Meridian is highest, al●…eit the Northern be greater than the ●…outhern: and four lowest, when the ●…he Sun toucheth lightly the Horizon. ●…. They have one Summer, and one ●…inter, but their Summer may be so ●…alled only Analogically: for these ●…laces of the Earth, are perpetually stiff ●…ith Snow and Ice. 6. They have four different Shadows, one from the East, one from the West, one from the South, and one from the North. Here are the Periscii. 7. The Gnomon, and styles of their Dial's, describes with their Points, Elliptical Figures.   

CHAP. XXI. Of the Phenomena of the seventh and last Position.  
1. THere are here no Stars, which either rise or set, but all of them are whirled about, equally distant from the Horizon. The Arctic and Antarctic Circles, are one and the same with the Horizon, and Equinoctial, which are now united. Understand this of the fixed Stars only; for the Planets absolving their course, rise and set, in their appointed times. 2. The Artificial Day is extended to half a Year; so is the Artificial Night, and therefore the quantity of the Natural Day, and the whole Year is one and the same. 3. When the Sun is in the Equinoctial, he shines only with half his Orb, and toucheth lightly the Horizon, and there he riseth and setteth only at those times. 4. No point of the Heavens, can be called, either West, East, South or North, seeing the Pole of the World doth not incline to any part of the Horizon, by which Inclination the four Points of the Universe, have their distinction. 5. They have only one Solstice, to wit, in Cancer, but Analogically two other may be added, to wit, when the Sun is in the beginning of Aries, and Libra. 6. There is one Summer and one Winter: but their Summer is rather to be called a slender slaking of the Cold. They have one Winter, because the Sun is under their Horizon a whole half Year together. 7. The Gnomon of their Dial's, describe with the extremity of the Shadow, upon an Horizontal Plain, perfect Circles.   
FINIS.   

Proteus Bound with Chains:  
OR,  
A Discovery of the Secrets of Nature, which are found in the Mercurial-Weather-Glass, unfolding the Reasons, and Causes, why before Fair Wether the Quicksilver Ascends, and before Foul Wether, it falls down, and Descends.  
A Subject not hitherto Treated of.  
TOGETHER  
With some brief Observes upon the Parisian Weatherglass, and an Explanation of the Sealed Weatherglass, and common Weatherglass.  
To all which is Added  
The Theory of the Wether, according to the Perpendicular Weatherglass.  
By GEORGE SINCLAR, sometime Professor of Philosophy in the College of GLASGOW.  Felix qui potuit rerum cognoscere causas. 
Edinburgh, Printed by the Heir of Andrew Anderson, Printer to His most Sacred Majesty, Anno Dom. 1688.   

Proteus bound with Chains: OR, A Discovery of the Secrets of Nature, which are found in the Mercurial Weatherglass, etc.  
THere are many excellent Questions to be Refolved, and Causes of the various Phenomena of Nature to be rendered, before a man can have knowledge to mount the Mercurial-Weather-Glass. Yet there are many, who rashly adventure, and bring upon that unerring and infallible Masterpiece of Nature, the scandalous and odious Character of Falibility, either by raising the Mercury too high, or fixing it too low in the Cylindrical-Glass, both which Extremes must be cautiously shunned. For if it be not ordered according to the Authentic Observations of the Wether for many Years past, it cannot but err. And herein its infallibility and perfection consists, to give the Theory of the Wether a just and determinate height, according to long Observation, and by consequence the top of the Cylinder the same height, none of which no ignorant person can do. The Questions to be resolved, are such as follow, 1. What sustains the Mercury in the Glass-Tube, whilst the Orifice is always downward, and open? 2. Why the Glass must exceed in length, one and thirty Inch? 3. Why the Mercury falls not down, if it be shorter than twenty and eight? 4. Why the Mercury is carried up with violence to the top of the Glass-Tube, whilst the Orifice is raised above the surface of the stagnant Mercury? 5. Why as much Mercury in height, is sustained in the wide Glass, as in the narrow? 6. Why, though the Glass were in height many Foot, yet the whole Mercury falls down to twenty and nine, or thirty Inch above the Cistern? 7. What fills up the space left empty behind? 8. Why the Mercury subsides by degrees, as the Weatherglass is carried up some high Mountain, and why it rises again, as it is carried down? 9 Why a Glass of thirty six Foot high is required to make a Wether Glass with Water in it? 10. What's the reason, I do not find the weight of the Mercury within the Glass, whilst I poise it between my Fingers, and yet I find another weight exactly the weight of it? 11. What that other weight is? All these and many more are fully and clearly resolved in my Philosophical Experiments twenty years ago.  
But there is a late Question, which troubleth all the Learned to resolve, which now I intent shortly to explain, viz. What's the reason, why the Quicksilver in the Weatherglass creeps up before Fair Wether, and falls down before Foul Wether? For an answer to this considerable Question, it is to be observed, that in the foulest Wether, I have found the Quicksilver fall down to twenty and eight, and in the driest, and fairest Wether, I have found it up at thirty and one Inch. From this excellent Phenomenon only, it is called the Weatherglass, Kat'exohen, by way of excellency: because before this alteration was found in it, it was called by the most part of Philosophers, the Torricellian Experiment.  
For clearing the Question in hand, I suppose that in the Beginning, there went up a Damp from the Earth to water the whole face of the Ground. Moses (Gen. 2.) relates now the ordinary means appointed by God in Nature, for bringing forth of Herbs, Bushes, and Trees out of the Ground, viz. the Damp, which causeth the Rain, and moisteneth the Earth, which Damp being by the heat of the Sun rarified, ascendeth to the middle Region of the Air, where by means of the coldness thereof, these Vapours are condensat, and thickened, and tur●…d into a Cloud, and afterward are turned into Rain, and so fall down.  
That there are such Damps and Vapours, which ascend from the Earth, and Waters, cannot rationally be denied; nay many Thousands and Millions of them ascend, which we do not see nor observe. I have seen in Frosty Mornings the mouths of Coal-sinks, and empty passages from waste Ground, where Coals have been digged out, Fumes and Vapours coming out so plentifully, as Fumes from a Salt-pan. Some do fitly compare this Earth to a Bag-pudding, taken out of a Boiling-pot, which sends forth Vapours in abundance. Likewise from the surfaces of standing and running Water, what numbers may be seen in a warm Summer's Evening. Nay from the Bodies of Men and Beasts, there is a perpetual Perspiration. But the finest and purest of all, are those which are exhaled from the Earth, and Waters. We see, that when the Sun is hot in Summer, the whole face of the Ground after Rain, covered over with Unduls, or little curled Waves, a small Gale of Wind being stirring, like unto the curled Waves of the Sea, Analogically. And so slender and pure are they, that whilst a man is among them, he cannot see them, but at a distance he may, looking alongs the face of the Ground. Likewise what multitudes of them may be seen alongs the surface of the Sea, a man standing at a considerable distance from the Coast. And so thick are they, that they have wonderfully lifted up, and magnified, much of the Land, and have made it appear, far otherwise than it was; nay, eclipsed whole Villages and Towns, and metamorphosed them into various shapes and forms, all which have come to pass, by reason of their multiplicity and thickness. Now these Vapours, flowing from the Earth and Waters, are carried up to the middle Region of the Air, where by process of time, they are condensat, and thickened, by the coldness thereof, and fall down in Rain.  
But here it may be inquired, By what cause, ●…r power, are these Vapours carried up, seeing they are Material things, and endued with weight? For answer, I must premit some few things, which do not ordinarily occur. First, That in all heavy Bodies, there is a twofold weight, one Specifical, the other Individual. The Specifical weight is found in Bodies, which differ by Nature, as Wood, and Stone, balanced one with another, equal quantity with equal quantity. ●… Individual weight, is likewise found in the same Bodies, but after a different way and manner. For example, Stone is naturally, or specifically heavier than Wood, putting equal quantity against equal quantity; for a Cubical-foot of Stone, is heavier, than a Cubical-foot of Water. Bodies of the same Individual weight, or such as are weighed in a pair of Scales, as a Pound of Lead, and a Pound of Wool, are individually of the same weight, but of different weight Specifically. Secondly, There are two sorts of Balances, the one Natural, the other Artificial. The Natural Balance, is the Mercurial Weatherglass, wherein the Mercury counterpoiseth the Air, and the Air the Mercury, both of them observing an equal Altitude, according to their natural weights: for since the Mercury is reckoned 14000 times heavier than the Air, the pillar of the one must be 14000 times lower than the other; and so both are of the same height, according to their Specifical weights. The Artificial Balance, is that Mechanical Power, called the Libra. Thirdly, That one Body naturally lighter than another, may become of equal weight, or heavier, than that other. For example, the Vapours, which ascend are far lighter specifically, than the Air, yet they become heavier specifically, when contracted, and reduced by a Cold, to a thicker habit, or consistency, and most of all when they are converted to Rain. But how shall it be known, that the Vapours are naturally lighter, than the Air? I answer, If it were possible to take an equal quantity of Vapours, with an equal quantity of Air, and weigh them in a Balance, the Air would be heavier. We know that Oil is lighter than Water, for being put under Water, it riseth to the Surface: so the Vapours go up thorough the Air, as Oil goeth up thorough the Water. Now I come to the Question in hand, and I affirm, that the Vapours are carried upward, not by the heat of the Sun, which is an vulgar error, but they being specifically, and naturally lighter, than the Air, are pressed up by it, as Smoak, till they come so far up, as the pressure of the Air, is able to carry them. I shall make this evident, by the following Experiment. Let a Diver go down to the bottom of the Sea, with a Bottle of Oil in his Hand, and pour it out there, he shall find, that such is the pressure of the Water, it shall drive it all up to the Surface above. For as the Oil is naturally lighter than the Water, so these Vapours are naturally lighter than the Air. Now these Vapours, which are infinite in number, ascending from all the parts of the Earth, to the Atmosphere many Miles above the Clouds, causeth the Air here below press with greater weight, upon the stagnant Mercury, and so raiseth the Quicksilver in the Wether Glass, one Inch or two, and sometimes three: for it is not possible, that the Air above, can be pressed down, and burdened, with that new weight, and addition of Vapours ascending, but the stagnant Mercury below must find the said pressure.  
But how are these Vapours condensat and thickened together, and fall down in Rain▪ I shall do this, by a most evident, and clear example. We cannot more fitly compare these Vapours, ascending and descending again in Rain, than to an Alembick, or Distillater. For these Fumes being carried upward within the Pot, and meeting with a cold Receptacle (for the Pipe descending goeth ordinarily thorough a Vessel full of cold Water) they are presently reduced, to their first condition, and fall down in Liquor. So are the Vapours, which ascend from the Stomach to the cold Brain received and distilled.  
But why should the falling down of the Rain cause the Quicksilver fall down, and why should the rising of the Vapours, cause the Quicksilver to rise? For clearing of this, it is to be adverted, that whilst the Mercury is up at one and thirty Inch, there is an equal balance or weight between the weight of the Atmosphere and the weight of the Quicksilver, so that there cannot be the least weight subtracted from the pressure of the Atmosphere, but as much must be subtracted, from the height of the Quicksilver: as by taking away one Ounce from this Scale of a Balance, the other presently goeth down, or by adding one Ounce to this Scale of a Balance, the other Scale presently goeth up. Hence is it, that the pressure of the Atmosphere becomes less, by the falling down of the Vapours, and consequently the height of the Quicksilver, must decresce also. And chose (which clears the second part of the Question) whilst the Vapours are ascending, and going up, the Atmosphere is more burdened, and by consequence the Quicksilver riseth, sometimes less, and sometimes more, sometimes one Inch, sometimes two or three.  
But how comes it to pass, that the whole Air, or that great and vast bulk of it, can be in equal weight, with so small a portion of Quicksilver, granting the Air to be so heavy, as is commonly reported? I answer, It is not the Air according to its thickness, or bulk, which makes any counterbalance with the Quicksilver, but it is the Air reckoned according to height, because Fluid Bodies do not counterpoise one another, according to all their dimensions, but only according to Altitude; this is only proper to Solid Bodies. For let never so much weight be added to the Air in thickness, itshall never make the least alteration in the Mercury. But if there be but the least addition made in height, the Quicksilver presently knows it, by rising and falling accordingly. For by how many thousand times the Air is specifically lighter than Quicksilver, by so many thousand times is the pillar of Air, higher than the pillar of Quicksilver. And chose, by how many thousand times the Quicksilver is naturally heavier than the Air, by so many thousand times must the Cylinder of Quicksilver, be shorter than the Cylinder of Air, which sustains it. The proportion is ordinarily reckoned as 1 to 14000. That is to say, one Cubick-Inch of Quicksilver counterpoiseth 14000 Cubick-Inches of Air, both being put into a Balance.  
It is evident from this, and many other things, that there is a proportion observed in all the Works of Nature, as here between the height of the Atmospere, and the height of the Quicksilver: for all the Lords Works, are made in Weight, Measure, and Number. This truth is so evident in the Mathematical part of Learning, that there is no need of proof. And if this proportion be not observed in things Artificial, viz. by Architects and Builders of Houses, the whole Fabric looks pitifully, and wants that face, and delicate aspect, it ought to have. And as the most wise Artist of the World, hath created all things in proportion one to another, so all the parts of his Holy Word, are in such a proportion one to another. For this we have Scripture, and Divine Authority: for it is said, Whether we prophesy, let us prophesy according to the proportion of Faith. The Original word is, Analogia Pisteos, well rendered in our Vulgar Language, the proportion of Faith, or Analogy of Faith, not as some, the Measure of Faith.  
GOD is not tied to Numbers, yet nevertheless, he doth and disposeth his Works, by Number, Weight, and Measure. It is observed, that after the going up out of Egypt, GOD caused to be numbered all the Israelites, from the Age of twenty years and upward, (Exod. 38. 26.) and there were found six hundred three thousand five hundred and fifty men. The year following, GOD commanded to make a second Review of the People, (Numb. 1. 46.) but without comprising the Levites, which had been numbered the first time with the other Tribes. Notwithstanding this Subtraction, and the Casualties, which might have changed the number of the People, since the year foregoing, it is found that their number was yet justly and precisely six hundred three thousand five hundred and fifty men. In which is seen a proportion which GOD held in the multiplication of that People. There is also observed a Mystery in the exact number of the two and twenty thousand Levites, which were then reckoned (Numb. 3. 39) For the rest, I contend not against the common opinion, touching the hundred forty and four thousand of the seventh of the Revelation, that they ought to be taken for an indefinite number, as well as the seven thousand which had not bowed the Knee to Baal. But it ought to be considered, why the Holy Ghost, who speaketh nothing superfluous, is not contented to have named the total sum of them, that were sealed in Israel, but also divideth it, in twelve times twelve thousand, distributed by equal portions among the twelve Tribes, every one of which is mentioned, the one after the other, with the expression of its particular number: for this showeth, that the number of the Elect, and the multitude of Believers, are measured by certain proportions, which are known to him, who is the Author. Certainly, the resemblance of the seventy Disciples of Christ, to the seventy Judges, which were substituted to Moses, and to the seventy Children, which jacob had when he went down into Egypt, is a line of this admirable Symmetry, with the which God hath limited, and proportioned the Body of the Church.  
Now this fortifieth that Maxim, that the number of the Elect cannot suffer addition, nor diminution: and that Election proceedeth not, from the Will of the Elect, but that of God, which prevented them. For it cannot be said, that all the Elect, from the beginning of the World to the end, have agreed together to make a Company composed precisely of a number certain and regular.  
But I return. It may be here inquired, Whether those Vapours, and Exhalations go perpetually up from the Earth, or not? 'Tis probable, that they are always ascending, though insensibly to us, and as many of them in the Night, as in the Daytime. Nay, more (it seems) in extreme Frost and Cold Wether, than at any other time; as we see in Greenland, where the greatest extremity of Cold is, there are infinite Treasures of Snow, which Snow could not fall down so plentifully, if there were not Vapours perpetually ascending. Next, after Rain, and the falling down of the Mercury to 28, or 29 Inch, I have found the ascent of it, in that same Night eight or ten Degrees, which could not happen, unless there had been an addition of new weight to the Atmosphere. And this is observed, to be rather in the Winter, than in the Summer Season, especially in calm Nights. I have observed, that the next Morning after Frost all the Night, the standing Waters in Furrows, which have remained many Days entire, dry up, and nothing remaining, but emptiness below a surface of thin white Y●…e. This Water could not sink into the Ground, more that Night, than many others before; but the Frost coming on, and the Air becoming dry have turned all the Waters into Vapours, and so have been exhaled.  
I would have it made more evident, how the greater pressure of the Atmospere by the weight of these Vapours make the Quicksilver rise in the Weatherglass? I answer, Take the Weatherglass, and place it within a dry Harbour, before the Water begin to flow. Then suppose the height of the Mercury to be eight and twenty Inch. I say, when once the Water hath flowed, but three Foot and a half in height, above the stagnant Mercury in the Cistern you will find the Mercury in the Weatherglass three Inch higher. For as the growing of the Tide above the stagnant Mercury raiseth it higher, and higher in the Glass, so the ascending of the Vapours loadneth the Atmosphere, more and more, and consequently it presseth with more weight upon the Mercury in the Cistern. And as the Vapours are turned into Rain, and the Mercury falls down; so by the ebbing of the Water, the three Inch of Mercury, falls down within the Weatherglass.  
It may be inquired, How far do these Vapours ascend? I answer, That Philosphers distinguish the Air into three Regions, the first, second, and third. But both Philosphers and Astronomers do vary exceedingly in determining the height of any of them. I shall not curiously inquire, but shall speak a little to what concerns the present purpose. 'Tis probable, that these thin and light Vapours, which flow out of the Earth and Waters, go many Miles above the Clouds, where there is neither Wind nor Rain: for the pressure of the Air being powerful many Miles up, must carry the Vapours, so far up. But to determine particularly, it is not possible, only in general they ascend very far. Now it is evident, that the Atmosphere, is composed, and consists of such Vapours being called Sphaera halituum, which no doubt, is of a considerable thickness, and height. These Vapours, when they are once past the inferior Region of the Air, which will not exceed an English Mile, and a half, go up quickly, and are received by the Atmosphere, where they accresce to a considerable height, perhaps 40 or 50 Mile above the Clouds, where by some extrinsic cause, as extremity of Cold, they fall down from the Atmosphere, first as Mist or Dew, till they come to the lowest Region, where in a very short time, they cover the whole Heavens, though never so clear before. How many times before Rain, will this be seen.  
Besides, there is above the Atmosphere, that which Astronomers call the Diluculum and the Crepusculum, that is, both the Dawning of the Day, and the Twilight in the Evening, the one beginning about two Hours before the Sun rise, and the other ending about two Hours after the Sun is gone down. For if that Crepusculum were not there, we should have no Light, until the Body of the Sun were above the Horizon, and should have no Light after the Body of the Sun is set. This Sphere is unalterable, and without accresce or decrease, but the Atmosphere is not so, by reason of the Vapours coming to it, and decreasing again. Next, the Refraction, which makes the Sun or Star to appear above the Horizon higher, than really it is, is caused by the Atmosphere. 'Tis observed by Shepherds, that if the Sun appear sooner above the Horizon, than ordinary, the Day following shall be Rainy. They see indeed the Image of the Sun, a little before he rise, which is caused by the Refraction, or thick Medium of the Vapours, which lie about the Horizon. For example, Let a man so fix his Eye, upon a wide Vessel, with an open mouth, with a piece of Money in the bottom, he shall not see it, till the Vessel be filled with Water. For Water being a thick Medium raiseth the Image of the Money, and brings it to the Eye by a broken and crooked Line, which is Radium refrangere, or rather refringere.  
It may be further inquired, Why the Clouds are sustained, or what keeps them up from falling down? This is a considerable Question, and well worthy of a Divine Answer. The Lord says to job, Dost thou know the balancing of the Clouds, the wondrous works of him who is perfect in Knowledge? The Clouds than are suspended, not miraculously, yet wonderfully by Natural Causes; for as a Ship is sustained from sinking by an even Balance with the Water, so are the Clouds keeped up, by an even and equal Balance with the pressure of the Air, which really sustains them. If they be light and thin, they go further up, but if they be heavy and black, they come nearer to the Earth, but are still in an equal Balance, with the pressure of the Air. And as the loaded Ship goeth further down in the Water, than the Ship, that's not burdened; so do the black and heavy Clouds swim lower, than the light and white Clouds. But when there is a great convocation of Clouds together in one place, each one presseth upon another, and so like Honey-Combs they distil their Drops upon the Earth. Note, That the greatest Ship in Europe, with all her Furniture for War, is but the just and exact weight of the Water, thrust out of its place by the Ships Water-draught.  
It may be yet inquired, How far are these Clouds from the Earth, which send down the Rain? I answer, The surest way to know, is by the Thunder. Observe then, how many Seconds of Time, do pass, between the first seeing of the Glance, and the hearing of the Crack. If the Noise be strait up, five or six will pass, which make an English Mile. In Mountainous Ground, which lieth higher, three at the most will intervene, about five hundred pass. To know exactly a Second of Time, whereof 3600 make an Hour, follow this method. Take a small Chord of thirty and seven Inch and a half exactly. To which append a Lead-bullet of seven or eight Ounce. Hang it so, that it may swing to and fro of its own accord. Each one of these Swings are a Second of Time.  
But may it not be affirmed, that the greater pressure of the Air, which raiseth the Quicksilver, is caused by the weight of the Clouds, which swim above us: and that the falling down of the Quicksilver is caused by the dissolution of these Clouds into Rain? I answer, This cannot be: for when the Heavens are most serene and clear, the Mercury is furthest up; and when the Heavens, are nubilous, and covered with Clouds, the Mercury many a time is furthest down.  
It may be inquired, Whether the cracking of Thunder, maketh any alteration upon the Weatherglass? I answer, There are three things to be considered in Thunder, First, The Lightning. Secondly, The Crack. Thirdly, The Thunderbolt: which three are lively represented to us by the shooting of a Cannon; for the Fire coming out of the Muzzle, represents the Lightning; the Report, represents the Crack; and the Bullet, the Thunderbolt. But there is a more lively representation of Thunder, in Aurum fulminans, which like the Thunderbolt carrieth its stroke downward, three Grains of which, though never so little made hot, takes Fire, and gives a greater Report, than two Ounces of Gunpowder, so stupendious is it. But there is nothing here, which can make any alteration upon the Wether▪ Glass.  
It may be inquired, If the Winds make any alteration upon it? I answer, Winds are nothing but Air agitated; nor Tempests, but Air-floods, or violent Agitations of the Air. These do really influence the Weatherglass, not only in causing the Quicksilver subside, and fall down, but in causing the top of the Mercury tremble, and make some visible reciprocations up and down, especially, when the Wind blows very high. Next, Winds which come from the South and South-west, by reason of much moistness, which they bring alongs with them, influenceth the Quicksilver much indeed. But Northerly Winds, which are more drying, have less influence. Nay Easterly and North▪ east Winds even with Rain, keep up the Mercury, and suffers it not to fall down so far, as other Winds. Because such Winds come from the Great Continent, bringing with them many Earthly Particles, and Atoms, which being dry, have not that influence upon it, as moist Winds from the South and West.  
It may be inquired, If the Weatherglass doth foretell Winds, as it doth Rain? I answer, It doth not so much foretell Winds, as it is actually influenced by them. Yet, if a man were a diligent Observer of the Winds, before they blow, and took narrow inspection of the Weatherglass, he would surely foresee them approaching, by some alteration or other in it.  
It may be inquired, Whether Mist or Fog, doth affect the Weatherglass? I Answer, Yes, for I have observed, when the Mercury has been up at Fair, the falling down of a Fog, hath brought it down three or four Degrees.  
It may be inquired, When the Mercury i●… at the highest Station, in the fairest Wether, as above Long Fair, how many Days doth it prognostic Rain, before it come▪ I Answer, When it first begins to alter, it must fall down to Long Fair, half an Inch; next to Fair, another half Inch. Thirdly, To Changeable, as much: And lastly, To Rain. This Motion is slow, and therefore it foretells, sometimes three Days, sometimes four, sometimes less▪ But this is sure, it cannot fall down in one Day so much bounds, nor in two, neither in three. I have seen it fall down from Long Fair to Fair, and then halt, by reason of some stirring Winds, or by reason, of some small change of Wether, in some County near hand. When it's far up, as at Long Fair, or above it, it is next to impossible, that either Wind or Rain can be.  
Some, who are not acquaint with the Weatherglass judge it erring, when they see the Mercury at Rain, and yet no Rain. I confess it may be so, if it be not rightly adjusted, at the first setting up; but if it be set, according to Art, the Mercury cannot be at Rain, but there must be Rain, either here, or some place near hand.  
It may be inquired, If Snow and Hail have the same effects upon the Weatherglass, which Rain have? I answer, Yes; for they are both from the same cause, namely moist Vapours. I have 〈◊〉 s the next adjacent Hills covered with Snow, when there was neither Rain nor Snow in the Valley Country, and the Mercury down at Rain, though it had been always up before the Snow fell. And many times it is found, that Rain falling in the next Shires, or Counties, though none here, have made the Quicksilver fall down to Rain. The last year 1687, in November, I have seen the Quicksilver, below Much Rain, and yet the Days going before, or following, have been pretty fair. But the Wether, was under a strong disposition, and inclination to be Tempestuous and Stormy, which soon followed. 'Tis observable, that the Quicksilver, is never so high in the Weatherglass, as about the hinder end of the Month of October, or rather in the Winter Season. In Rainy Years, I have not seen the Mercury further up than Fair, and that seldom.  
Might the Weatherglass be useful in Ships? I answer, Yes; but the commotion of the Ship, (you say) renders it useless. I answer, it might be so suspended, that it might hang always perpendicular. And though this were not, yet the Nature of it is such, that it can recline without hurt, as much as the Ship can●…ly, either to Starboard, or Larboard, and fall right again, when the Helm is righted. In a word, whatever advantage a man might have by it, in his Chamber, he may have as much, by having it in his Cabin.  
There is a person of Honour, and great Learning, who hath written lately in Natural Philosophy, and among other things, hath not omitted to show the reason of this marvellous Phenomenon, whereof I have been Treating. He toucheth it briefly in 9 or 10 Lines, and says, Id autem mirum satis videtur, etc. 'Tis a strange thing (says he) that in Rainy and Windy Wether, when the Air seems to be heaviest, yet the Mercury is furthest down. The reason (says he) is taken from the temperament of the Air, where the Clouds are; for when the Clouds are grosser, tho much elevated, they intercept the Rays of the Sun, and are thereby melted, and turned into Rain. And the Air being eased of the burden of these Clouds, and being rarified above, by the Sunbeams, is becomes lighter, and so bears less down the surface of the stagnant Mercury in the Cistern. But when the Air is nubilous and Cloudy, the weight of the Air, is augmented, by the weight of the Clouds, which make it press with greater weight upon the stagnant Mercury in the Cistern.  
I dare not oppose any thing to the Opinion, of such an eminent man, though I might, he being a hundred Stages beyond many. Yet there are not some wanting, who male-apartly set at nought his Philosophical System, as insufficient both for Matter, and Form; whereas among all the Learned Abroad, his Writings are held in great Estimation.  
There is one of the Professors of Philosophy at Aberdeen, whose public Theses the last Year, came to my view: yet I shall adventure to say something anent them. The Author, (whom I have not the favour to know) seems to be well acquaint with the new Philosophy, and a good Scholar. He confutes rationally Malebranch, and Spinosa, two wild Philosophers. He seems to be a Cartesian in his Philosophy, yet affirms that the Demonstration (as he calls it) of God's Existence, by the Idea, being abstract and Metaphysical, goeth far beyond the capacity of the Vulgar, and therefore being compelled by Reason, he averreth, that the Apostle Paul reasons far better in the first to the Romans.  
He speaks honourably of the late Lord Precedent in confuting some of his Doctrine, for which he deserveth more thanks for his good Estimation of him, than for the strength of his Reasonings against him. He hopes the Lord Stair, will hold him excused, if he do not acquiesce to his Decisions. This seems to be jestingly spoken. Casting my Eye further thorough, I found somewhat anent the Causes of Winds, Tempests, and Rain, and the reason why the Atmosphere, is sometimes lighter, and sometimes heavier. But he hath not touched the Nail upon the Head.  

Some Notes upon the Parisian Weatherglass.  
THere is a New Invention of a Weatherglass, which cometh from Paris (facile est inventis addere,) set in a curious gilded Frame, more specious to behold, than profitable and useful. It is liable to several Abatements. The first makes it a dumb Weatherglass, wanting the whole Theory of the Wether, so that when a man looks to it, he knows not whether it shall be Fair or Foul. A man seeth indeed the sides of the Frame, divided by French Measure into Inches and half Inches; but these Measures have no signification of the Wether. When a man looks upon it in the Morning, he sees the Tinctured Liquor at such a height; and in the Afternoon, he observes again, and finds it higher or lower. This is all it signifieth. And if perhaps he be informed that in Fair Wether, the Liquor descends, and in Foul Wether it ascends, than he may conclude, observing it further down than it was, that it is probable to be Fair.  
The second Abatement is, that there are two Oval-Glasses, which rather ought to be Cylindrical. Now unless there be a just and exact measure in height, between the top of the one Oval-Glass, and the bottom of the other, it cannot be un-erring, or between the middle of the one, and the middle of the other. Because the Mercury cannot raise the Liquor in the right side, by equal portions, since the rising of it depends essentially upon the falling down of the Mercury from the left Oval-Glass. For the Glass being in form of a Pullet's Egg, more Mercury falls down, whilst it is terminate about the middle, being there wider, than whilst the Mercury, is near either of the extremes, which are narrower. And I believe the Contriver hath foreseen this.  
The third Abatement is, that the Tinctured Liquor is subject to Corruption, the Orifice of the Glass being open, suffering Evaporation, by which means, the whole Contrivance is rendered useless.  
The fourth Abatement is, that the Orifice of the Glass, upon the left Hand, must be Hermetically Sealed, which few or none can do.  
The fifth Abatement is, if it be once Mounted, and set a going, it cannot be well Dismounted, for the end which is Hermetically Sealed, must be opened, and cannot be well Sealed again.  
Lastly, The Glass is brought Home from Abroad, not without hazard of breaking, the Glasses being very small and slender.  
But there are none of these Difficulties found in the Perpendicular Glass. For it may be set up, and dismounted, as oft as you please, and transported from one place to another. And the excellency of it is, that it sets itself; for whatever weight of Mercury it once takes, the same will suffice it for ever. And which is marvellous, the Mercury falls down always according to the Nature of the Wether, and there halts, whether it be Fair, or Foul.  
There is a second sort of Weatherglass much in use, called the Sealed Weatherglass, whose use is only to show the Heat and Coldness of the Air. It hath a round Glass below, about two Inch in Diameter, and a Stem going up from it, about a Foot and a half in length, but slender and narrow within. This Glass is filled with the finest Spirit of Wine, three or four times distilled, so in effect, being full of fiery Spirits, the least Heat or Warmness in the Air, rarifieth it, and the least Coldness contracteth it. When the Ball is once full, and the Stem too, the open Orifice above is Hermetically Sealed, and coming to the cold Air, from the warm place it was in, the Liquor creeps down towards the Ball, and by this means, it demonstrats by its creeping up, the warmness of the Air, and by creeping down it shows the Degrees of Cold. It is Hermetically Sealed, that the outward▪ Air, may have no influence upon it. It is set in a curious gilded Frame, with the several Degrees of Heat and Cold affixed to it. They come from Paris, and London, not without hazard of breaking by the way.  
There is a third sort, specially different from the rest, called the Water Weatherglass. It hath a round Head above, with a long Stem going down from it, and the Mouth below remaining open, is drowned among Tinctured Water. To set it a going, they use to warm the Head, and Body of it, at the Fire, and then to thrust the open end among the Liquor in the Cistern. When the heat begins to abate in the top, the Air within, begins to contra●… itself, and so the Water follows up, and hangs about the middle of the Stem. This in cold Wether creeps up, and in warm Wether creeps down. It creeps up for fear of Vacuity, as was maintained long since, before the pressure of the Air was known by the Torricellian Experiment. This Weatherglass was esteemed infallible; but now it is known to be most fallacious, and uncertain. The reason is, because it is acted and moved, not only with Heat and Cold, but with the greater and lesser pressure of the Air. If it be demanded, how shall I know, whether it be the coldness of the Air, or the greater pressure of the Air, which causeth the Water to ascend: and whether it be, the warmness of the Air, or the jesser pressure of the Air which causeth the Water to descend? I answer, It is difficult to know; for both do sometime concur, that is, the weight and greater pressure of the Air, and the coldness too. And sometime the lesser pressure of the Air with warmness, make the Water fall down. And sometime the greater pressure of the Air raiseth the Water, without any addition of Cold: And sometimes the addition of Cold, without any alteration in the Air, as to more weight, will raise it. And though by this means it be fallacious, yet many notable Phenomena do appear from it. By the help of this, and the Mercurial-Weather-Glass, and the Sealed one, and by the help of the Hygroscope, which marvellously shows the least alteration in the Air, as to Moisture and Dryness, and by contemplating the Heavens, the Sky and the Clouds, and considering the Winds, how they blow, and the various Aspects of the Planets one to another, (as Stargazers do affirm) men might come to foretell the Wether particularly.   

The Theory of the Wether, according to the Mercurial-Weather-Glass.  
THE Theory of the Wether, is either Engraven upon Brass-Plates tichtly polished, or upon a piece of Lombard-paper, wrought in the Taliduse-press. The Brass, or the Paper, is divided into Six half Inches; and every half Inch into Five Degrees; or every whole Inch into Ten equal parts. I call the upmost Station, Long Fair; the second half an Inch under it, Fair: the third, Changeable: the fourth, Rain: the fifth, Much Rain: the sixth, Storm●…; and if you please to add the seventh, call it Tempests. These six or seven, contain the whole Alterations, which use to be in the Wether. When the top of the Quicksilver is at Long Fair, it toucheth exactly the Line under it. If it fall down, it is said to be one Degree under Long Fair, or two or three, accordingly as it falls down, till the top be at the Line under Fair, and then it is Fair Wether, and so of the rest of the Stations. It may be asked, At what height, must Long Fair be affixed? I answer, The Situation of the place must be considered, and the Climate under which we live: for a Glass appropriated to this Parallel, will not serve in the Braes of Athol, or Annandale. And if there be not a just, and exact height, to a Hairs breadth, of all the Stations from below, it cannot be un-erring. The several Stations are found out, not by Algebra, or any Mathematical Demonstration, but by many years' Observations. Whosoever taketh upon him to mount a Weatherglass, without the knowledge of these Praecognita, he plays but the Fool.  
There are many other things necessary to be known, which every Fallow, which hath no more in his Scull, but a Bag-pudding in stead of Brains, is not capable to understand.  
I shall briefly run thorough the several Stations, with some Observes upon each one of them. In the first and upmost, is Long Fair, or most pleasant Wether. I have seen the Quicksilver sometimes above it, yet seldom doth this fall out, but in extraordinary Seasons. The Mercury being at this height, it is next to impossible, either to be Wind or Rain. Nothing for several Days, but settled calm Wether. Sometime the Heavens are covered with dry and grey Clouds, but not the least appearance of Rain.  
The second ●…tation, half an Inch lower, is Fair. The Mercury being here, I have observed a small Shower of Rain to fall, from the lowest Region of the Air, as a th●…ck Dew or Mist, but immediately after, the Day became Clear and Fair. The whole year 1686 almost, it was a rare thing to see the Mercury up at Fair, but frequently below Rain, and Changeable, because of the frequent Rains, which fell out that year. And which is observable, all that Summer, the Hygroscope went not once about, whereas in dry Summers, it goeth twice about, sometimes more and sometimes less.  
The third Station half an Inch lower, is Changeable. That is, sometimes Fair, sometimes Foul, sometimes Frost, sometimes Thaw, sometimes Sleet, and sometimes Snow, sometimes Wind, and sometimes Calm.  
The fourth Station is Rain, not actually Rain, but a stormy inclination in the Air to be Rain, and sometimes Rain. Nay, sometimes the whole Day will be Fair. But still the Rain is approaching, or hath been Rain, either here, or some place about.  
The fifth Station is Much Rain, the worst of Wether almost, as in the Summer, or Winter Season, when Rain is accompanied with stormy South-west Winds, or westerly Winds. This last October, or November, I have seen the Mercury below this Station, and yet no Rain in the mean time, nor all the Day, but the Sky black, and tempestuous, thick Clouds lying about the Horizon. Above Fife, great Heaps of them: some like Castles and Towers, others like ragged Rocks, hanging over each one another. All of them forerunners of Rain.  
The sixth Station, Stormy, extraordinary Foul Wether.  
In the last place, I have subjoined Tempests, or Hirricano's, which do not fall out in this Country. If it be asked, Why doth not the Mercury fall down to Tempests? And why doth it not go half an Inch above Long Fair? I answer, There are here two Tropics, namely Storms, the nethermost, and Long Fair the upmost. Above this, the Air is not able to press, except some few Degrees. And at Storms the pressure is least. The length of the Tropics then, are about three Inch.  
General Rules. The further the Mercury goeth up, the Wether inclines to be the Fairer, and the further it falls down, it inclines to be the Fouler. Secondly, When the Mercury is highest, Fair Wether seems to be universal; when it is lowest, Foul Wether seems to be universal. Thirdly, It is not so much Foul Wether actually, which influenceth the Mercury, as it is the Disposition and Inclination of the Wether to be Foul: so that the Mercury will be many times at Rain, when it is not actually Raining, which is wanting when the Quicksilver, is at Fair, or Long Fair. Fourthly, Not only Foul Wether in this County or Shire, maketh the Mercury fall down, but Foul Wether, in the next adjacent County, though there be none here: as the Weatherglass at Edinburgh, will be altered, with Rain in Tweeddale, or in Lammer-moor. And as it shows the Nature of the Wether, so it predicts and foretells, sometimes a Day, sometimes two or three, if so be the Mercury hath been far up. But if it hath been only at Changeable, or below Fair, it predicts some few Hours, before it be Rain, by falling down a Degree, two or three, or four. When it is a falling down, the top of the Mercury is flat and level, but when it is a rising, it is somewhat round.  
'Tis said, that the Ladies, and Gentlewomen at London do Apparel themselves in the Morning by the Weatherglass. Whatever be in this, 'tis certain, that when a man riseth in the Morning, he may know infallibly, what sort of Wether will fall out ere Night.  
It is most useful for the Husbandman, both in Seedtime, and Harvest, and for winning of Hay. It is useful for taking a Journey, for when I see the Mercury up at Fair, or Long Fair, I may be confident, there shall be no Rain for eight or ten Days, chiefly when it's up at Long Fair.  
There are many other uses, for which it is profitable, which are needless here to repeat. It is always infallible, because guided by God in Nature, though to our apprehension it seems to err. There are so many Changes, and Alterations in the Air, that a particular Rule cannot be assigned for each one of them. But the general Observations which are affixed, are sure. If any man would find out all these Intricacies, he must diligently observe, the Changes, and Quarters of the Moon, and the several Aspects of the Planets, and the Winds how they blow, comparing them with the Changes and Alterations of the Weatherglass. Neither can it be subject to Corruption, though it stand an hundred year. The Glass cannot fail, neither the Quicksilver, which are incorruptible by Nature. Neither can the Frame decay, for many years, being made of Oak.   
FINIS.   

Postscript.  
To Buoy up a Ship, of any Burden, from the Ground of the Sea.  
THE Art of Diving hath not been much known, but of late; for it depends essentially upon the knowledge of the pressure of Fluid Bodies, which knowledge hath not been further known to the generality of Learned Men, than by name: though some ignorantly have averred, that the hydrostatics, is a Science long ago perfected. Among the first, who have essayed in this Nation, was the late Marquis of Argile, who having obtained a Patent from the King, of one of the Spanish Armado, which was sunk in the Isle of Mull, anno 1588., employed james Colquhoun of Glasgow, a man of singular knowledge, and skill, in all Mechanical Arts and Sciences. This man, not knowing the Diving Bell, went down several times, the Air from above, being communicated to his Lungs, by a long Pipe of Leather. He only viewed, and surveyed the Ship, but I suppose buoyed nothing up. About the year 1664, when this Art became more perfected, and was advanced, by the Practice, and Invention, of Learned Men. The late Lord Argile did employ a most ingenious Gentleman, the Laird of Melgim, who went down with a Diving Bell, and made a further inquiry. After some pains, and labour, he buoyed up three Guns, one of Iron, judging it to be of some other Metal, one of Copper, and one of Brass, about eight Foot long apeice, and eight Inches of Diameter. The third Essay was made by the late Earl of Argile himself, several years after, who did more. There was one Captain Smith, who undertook after that, yet more, who thought himself so sure of the Spanish Gold, that he would not suffer a Carpenter with himself: but this Interprize turned to nought. To effectuate the Proposal, I shall offer these six Propositions, which with small pains may be made evident, from Hydrostatical Principles; and next infer some Conclusions, needful for the design in hand.  
First, The whole Ship, with all its Loadning, is the just and precise weight, of as much Water, as the lower part of the Hull expels, or is expelled by the Ships Water-draught.  
Secondly, When the Ship becomes heavier than the said quantity of Water, it sinks.  
Thirdly, Water doth not weigh in Water. This is evident, for when a man pulls a Bucket full of Water from the bottom of a Well, he finds no weight thereof, till it come to the Surface.  
Fourthly, Nothing lighter in specie than Water, or of the same weight with Water, can sink. Hence, neither Timber, Wine, Bear, nor Oil, can tarry at the Sea Ground, but must be buoyed up of necessity.  
Fifthly, By how much, the whole Timber of the Ship, is lighter in specie, than as much Water equal to it in bulk, by so much is it the more able to buoy up. Imagine, the whole Timber of the Ship, reduced to a Cube of so many Foot, and a Cube of Water given of the same quantity. Now I say, as many Pounds, as this Cube of Water, is heavier, than that of Timber, so many Pounds of Iron, Led or Stone, will the Ship buoy up, or support, even though full of Water.  
Sixthly, A heavy Body, as Iron, Led or Stone, weighs as much less in Water, than in Air, as the quantity of Water it expels. A Square Foot of Lead, which I suppose weighs in the Air 728 Pound, weighs but 672 Pound in the Water, less by 56, the weight of a Square Foot of Water.  
From these Propositions, I infer, that when a Ship is to be buoyed up from the Ground of the Sea, nothing of her weighs, save her Ballast. By Ballast, I understand, taking the word largely, every thing in the Ship, heavier in specie, than Water, as Guns, Ankers, Bullets of Iron, and Led, Iron-bolts, Nails, and all manner of Ironwork. Next, That the whole weight of the Ballast, doth not preponderate or weigh down. Lastly, That the Timber of the Ship, and all things in it, lighter in specie, than Water, concur for buoying up the Ballast.  
The best expedient for raising of Ships entirely, are Arks of Wood, applied either to the sides of the Ship without, or just above the Orlop. These Arks must be so close, on all sides, that neither Air, nor Water, can pass. The Ark, to describe it more particularly, must have four Sides, and a Cover above, but open completely below. At every Corner, next to the Mouth, must be fixed, a strong Iron-Ring. Four likewise above, that is, one in each Corner, answering to the four below, which are for fixing a second Ark above the first, if need be. If the Ship, which is to be raised, be twenty Foot over, make your Ark twenty Foot wide, and as much in height. Bring it just over the place, where the Ship lieth, and filling it with Water, that it may sink without difficulty, thrust it down, till it come just above the Orlop, and fasten it within five or six Foot of the same, with Ropes passing thorough the four Rings, and the Beams or Balks of the Ship. The Arks being thus fastened to the Ship, by a Diver, the next work is to beget a power, or force within it, which shall be able to buoy up the Ship from the Ground of the Sea. This may be done, either by sending down Buckets full of Air, with their Mouth foremost, one after another, from the Surface of the Water, and then cause a Diver receive them, and thrusting them somewhat within the Mouth of the Ark, turn up the Orifice, by which means, the whole Air in it, shall ascend up thorough the Water of the Ark, and rest above, next to the top. This Device being often repeated, will at last expel, the whole Water of the Ark, and fill it completely with Air. This is so sure an Experiment, that none needs to call it in question. Or by communicating Air to the Ark from above, by the help of a pair of large Bellows, and long Pipes of Leather, going down within the Mouth of the Ark. Or thirdly, By the multiplication of Bladders full of Wind, filling the Ark within, which may be done more easily. The Ark being oncefull of Air, will have a considerable pull with it, which is more, and less, according to the dimensions thereof. For knowing this, you must consider, that whatever t●…e dimensions of the Ark are, it will buoy up, as much weight as the Water weighs, which fills it. I●… then, the Ark be twenty Foot wide, and as much in height, it must contain eight thousand Square Foot of Water; and since every Square Foot of Water thereof weighs fifty six pound Trois, the whole must be 448000. An Ark then of twenty Foot Square, will buoy up, four hundred and forty eight thousand pound weight, the weight of 58 Cannons Royal, each one whereof, I suppose weighs 8000 pound. Or the weight of 74 Demi-cannons, or the weight of 97 Culverings: or of 149 Demi-culverins: or of 298 Sakers, each one of this sort weighing 1500 pound. Or lastly, the weight of 250 Tun of Wine, reckoning four Hogsheads to a Tun, and each one of these weighing 448 pound.  
If you fasten a second Ark above the first, by the help of the Rings upon the top, which I mentioned, both will buoy up together 896000 pound, the weight of 112 Cannons Royal. But if your Ark be 30 Foot in all its dimensions, it must contain twenty and seven thousand Square Foot of Water, which will weigh, one million, five hundred and twelve thousand pound weight of the weight of 189 Cannons Royal, or the burden of 252 Demi-cannons, which is the weight of 844 Tun of Wine. But supposing the Ark to be more in quantity, the one way than the other, that is 40 Footlong, it shall be able to buoy up, two million and sixteen thousand pound, the weight of 252 Cannons Royal, or the weight of 1125 Tun of Wine, or Water.  
If the Arks be applied to the sides of the Ship, you must fix, as many upon the one side, as upon the other, which need not be so large, as those which are fastened upon the Orlop. I shall suppose, that upon each side, there are four Arks, each one 10 Foot Square. If this be, every single Ark, must contain 1000 Square Foot of Water, which will weigh fifty six thousand pound. All of them together, therefore must buoy up 448000 pound weight, the burden of 56 Cannons Royal.  
To know, how to proportion the quantity of your Ark, to the burden of the Ship, which is the great secret, follow this Method. Consider first, that neither the Timber of the Ship, nor the Water which is in her, nor any other thing, which is lighter in specie than Water, (that is, any thing which floats upon the Surface) or of the same weight, with it, preponderats, or weighs down, but only what is heavier in specie, than Water, as Guns, Ankers, Iron-bolts, Iron-nails, and such like, the just quantity, or very near, may be found. Calculate then, as near as you can, and supposing the weight of all this Ballast, to be about 448000 pound; you must next consider, what the dimensions of the Ark, must be, which is able to buoy up so much weight, which may be found out thus. Divide the just account of your Ballast by 56, and the Cubique Root of the Product, gives you the just dimensions of the Ark. For example, Divide 448000 by 56, and you will find 8000, the Cubique Root whereof is 20, the quantity of your Ark within.  
If you judge▪ it more convenient to apply lesser Arks, namely to the sides of the Ship, ye may have eight, by dividing this into so many parts, four for each side, and every single Ark 10 Foot Square, which are equivalent. Remember, that though the whole Ballast, weigh 448000 pound, yet this whole weight is not to be buoyed up by the Ark, seeing heavy Bodies weigh less in Water, than in Air, according to the sixth Proposition.  
As for fastening the Arks, either to the sides of the Ship, or just above the Orlop, several ways may be thought upon, which I leave to the Invention of others, who are skilful in building of Ships. Let it suffice, that I have made it probable, if not evident with Reason, that the greatest Ship may be buoyed entirely up from the ground of the Sea, which was the thing to be demonstrated.  
If it be Objected, That the strong pressure of the Water, will put the Ark in hazard of bursting, when its full of Air. I answer, There is here not so much hazard, as every one may believe. The Reason is, because the pressure within the Ark, is very near equal, to the pressure from without. This I add, because the top of the Ark within, is more pressed up by the Air within, than it is pressed down with the Water without. The pressure upon the sides, is more uniform, and so there is the less hazard there. In a word, if the Ark be able to support, as much Water, as fills it, without bursting, it shall go down thorough the deepest Water imaginable without trouble. That is, hang it by Ropes in the Air, full of Water. If the bottom be able to support this weight, there shall be no hazard of bursting, when it's full of Air within the deepest Water.  
From this unequal pressure, which the top of the Ark suffers, it follows of necessity, that if there be any Rift, or Leck in it, the whole Air will go out by degrees, and so render the Ark useless. I answer, this endeavour, which the Air within, hath to be out, is just the same, with that, which the Water within, hath to be out, when the Ark is full, and hung in the Air with Ropes. If Art can cure the one, it may find a remedy for the other also. But I leave this to such as are skilful in Calking of Ships.  
Tho I seem to insinuate, that the Arks must be Cubical or Foursquare in their form, yet there is no necessity for that; for they may be made under what fashion or form you please, provided they contain, as much Air as will be sufficient to raise the Vessel. And though I mention Arks of 20 or 30 Foot Square, which will go near to buoy up the greatest Ships, as Men of War; yet for ordinary Vessels, Arks of far less size will suffice.  
Some may imagine, that a Ship sunk (for example) with Coal, is as difficult to buoy up, as to raise her out of a dry Harbour. But this cannot be, since a pound of Coal, will not weigh three or four Ounce in the Water. A Ship loadned with Wine or Oil, weighs nothing at all in the Water, but may be very easily buoyed up, if the Ballast be considered, as I said. Many Ships have been buoyed up entirely, by thrusting down empty Hogsheads, and putting them below the Deck. But here occurs a difficulty, if the Water exceed eight or nine Fathom, the strong pressure of it crusheth the sides of the Hogshead together. But here is a sovereign cure against that trouble. Bore a small Hole in any part of the Vessel, where you please: for the Water entering, brings the Air within, to press equally with the Water without.  
Tho this Invention, may seem difficult to some, to be made practicable, yet to such who are intelligent, and know well the Principles of the hydrostatics, it appears plain and easy. But the very Speculation of it wants not its own pleasure, being founded upon infallible and sure Conclusions, drawn from the surest grounds in Nature.  Labour improbus omnia vincit.