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VENTILATION

SCHOOL HOUSES.

BOSTOlSr:

J. H. EASTBURN CITY PEINTER.

(

REPOETS

OTHER DOCUMENTS

*■' -^ * ^ 1

RELATING TO THE

YENTILATI

^ ^..' * ^ .:^

SCHOOL HOUSES

CITY OF BOSTON.

BOSTOMIA itf
COSDITA^. ^^

^„ 1830. -^^

BOSTON:

1848.

JOHN H. EASTBURN CITY PRINTER.

PREFATORY NOTE.

At a meeting of the School Committee, December 9, 1847,
the Committee on Ventilation made their second and final Re-
port, which was ordered to be printed.

At a subsequent meeting the following Order was passed :

"CITY OF BOSTON.

" In School Committee, December 29, 1847.

" Ordered, That the Committee on Ventilation, be instructed to
append to their late Report on Ventilation, such parts of their
previous Reports on the same subject, and such special directions
to the Masters, as they may think advantageous.
"A true copy.

"Attest, S. F. McCleart, Secretary."

In February, 1846, a Sub-Committee of the School Commit-
tee, consisting of Messrs. Clark, Loring, and Brooks, was appoint-
ed, in the words of the Order, " to consider the subject of Ventila-
tion of the School houses under the care of this Board, and to
Report at a future meeting, some method of remedying the very
defective manner in which it is at present accomplished.

"And said Committee are authorized to ventilate, as a matter of
experiment, any two School houses in such manner as they may
deem expedient."

In December of the same year, (1846), this Committee made a
Report, containing their views upon the subject, and the result of
their investigations of the condition of the School houses, &c., from
which the following passages, after undergoing some necessary
revision, have been extracted.

It is believed, that these Reports, with their accompanying doc-
uments, now contain information upon all points necessary to be
understood, in order to ventilate any School house in a perfectly
satisfactory manner.

Boston, December, 1847.

Men, and women, und liUle children, husband. anC 1
mdfalever^jy^, „„„, a„d ,„oO.«ri, were h.nped uboui ih*
>nderry, o.Hoor of the calun in disorder, some wiih then

with

^ Uij ! . i ' : i;.L^ :. i)ucainber,adreadral

loiik pluctj UQ board llic aleemer Londoi

her p!i*«ag« from Sligo to Liverpool, by wliich op clothes torn from iheir backs in lailers, soniB
wards of seventy person., men, w..men, and chil 'heir bands and face, laceriiled. f""'° 7/*"/;'"''
, . .V, ■ I «r .- 't\ features tro.iden into u muni.i.y by the jron-shod

drtn.lon iheir lives l-y^^ffocjlion. Ihc particu |«^^^'°;^^^^ , ^^ their fellow-sufferers; here a father
lar. are thui related : /"%> ^^ ^ lomk^d in the armrt of hi. daughter; ihero a sisie-

"It appears that about four o'clook on the cve-<.|ineini? la the eorpso of her brother, their counte-
ning of the 1st Dccenibur, the steamboat London- n,npt.g black and distorted with the convulsions
icrry left the barbur of Sligo. There were on board produced by suffocation.

hor Ibreo cabin passengers, a numt)er of ehoep ami 'ii,e followMi(i; is a description of the scene which
ox.n, and about 150 emigrants. The vt-ssul was met the eye of th»i mats whfn a sieeras* passenger
crossing over to ihis port, whence the majority oi ^^(,o had, ui last, forced liis way out, coiiimouicaled
the untortunato passengers intended to proceed m- jq him the terrible intelligence :
einigraiiis to Ain<rica. Towards nightlull a heavy 'The mate instantly became alarmed, and ob-
gale cume on, and at last blew with so much vio- tainin" a lantern, went down to render aesistance
lence, that bhortly afier midnigbt, or rather towarda jjuch "however, was tha foul state of the air in the
one o'clock on Sjtu.day iiiornin< -■ ■ ■
cleared of all except the seamen

iengers, perhaps one hundred and fifty in number, guished. At length, on the tarpaulin be.ng com-
wcie crowded into the (ore cabin, men, women and pletely removed, and a free access of air admitted,
<:hildren, all wore driven below —driven, we say, ihe real nature of the catastrophe exhibited itself —
because several struggled against those who forceu There lay, in heaps, the living, the dying, and the
them down the companion ladder. j^j^j one frightful mass of mingled agony and d'-aih.

After some ditliculty, however, many remonstran- ji spectacle enough to appal the stoutest heart. Men,
ces, and much opposition, the poor emigrants were «yomen, and children were hpddled together, bUck-
crammod into the narrow compass oftho fore-cabin, ^ned with sulTocation, distorted by convuleions,
it coQipariment little moro than eighteen feet long bruised and bleeding from the desperate straggle for
hy eleven feet wide, and seven (eet high. The existence which preceded the moinent when ex-

ing, the decks were cabin, thnt the light was immediately extinguished
en. The steerage pas- a second was obtained, and ii, too, was extin

pace was capable only of accomiiiodaling about for-
ly passenger!), and here were nearly one hundred
-ind bfiy of both sexes, huddled together indiscrimi-
nately, the old and the young, the robust and the
sickly, the adult and the infant. Meanwhile, the
sea was running hi^h in the' channel, so ^hat tbt-
waves repeatedly broke over the steamer. Then ii
was that, through the negligence of ihorO who wen
responsible for the lives ul the people on boaid. a
measure of momentary convenience waa adopted
which led to a catastrophe the like of which Ims on-
ly occurred before in the notorious prison of Culcut
la. 'l"he companion, the only aperluru by which
the fore-cabin received ventilation, was closed, ami
)ver the companion was nailed down a piece of tar-
paulin!

1 his was at about midnight between Friday and
r^atarday. The result proved to be only such as*
coiiiiiiun sense would mil every one was inevitable
The dizzinetis and qualms of aea-sickness were verN
«oon forgotten in unendurable sensations of sufibca-
tion. ElFirts were made to force a way out of the
confinement: they were found to be unavailing
^houts were raised to attract attention; they whip
drowned in the roaring noise of the storm. And
then, according to the description of the few cur
vivors, ensuiid a npnctacle sucti as sets the imagina-
tion of evi;n the most moibul at defiance. The
.iieamer drove bravely through the tempest, whil.
ilio.e who directed her remained wholly unconscious-
ol the frishiful conllint for life and death wllkh was
ihen raging in her vtiry entrails.

The trampling and Ix-aiii g sounds within the cab-
in were rendered inaudible by the throbbing ol ih)
pistons, and the shrieks and ^rouiis of ihe sullererk
(inly died away with the gale towards moriiin{i
Not until ilifu were tlin seamen awatn of the Irage
dy which had burn enacted under their feet. Oui
of the one hundred and tifly passengers who had
been driven down the companinn-lidder a few hi>ur>-
before, seventy-two were found lo have perished !

blasted nature resigned the strife. After some-time
',he living were separated from the dead, and it was
'.hen found thtt the latter amounted lo nearly one-
"lalf of the entire number.'

■ Captain Johnstone appears at length to have been
iiade aware that he had become a main actor in a
scene of the most horrible calamity. But he was
uncertain what to do. He put hi* steamer into
Lough Foyle. but it was twelve hours before he
could make np his mind to paaa up to the quay at

\ The coroner's jary have found Alexander John-
Itone, captain, Richard Hughes, first mate, and
Ninian Crawford, second mate of the Londonderry,
fcuiliy of maii^laujihter, and have expressed in the
stronaBSt terms their abhorrence of the inhuman
conductor the other seamen oa board, throughout
this unhappy transaction."

The steamship America Capt. Loitch, from Wew
York, Nov. 22d, arrived in the Mersey afternoon ol
4ih in'st., having made the passage in about 12 days.
I The steamship Acadia, Capt. Stene, arrived at Liv-
erpool 12ih A. M., in les. than thirteen days from
! Boston. The steamship Washingion, Capt. John-
; ston from Now York, 20ih ult, arrived at Southamp-
ton on the 5ih inst.

The steamship Herman, Capt. Crablree, sailec
I from tjouthampton. on the I2ib December, for New
Vortf wah «!».«.--• (jnd a large freight list.

->»'

«!•'

Death from Asthra'cite Coal Gas. AW'
old man named Ttiomas Fitzpairick died yester .
day at his residence in 7lh street below Wharton,
from the effects of Anthracite Coal ?as inhaled
hy him during Saturday night. His son was
likewise nffected hy it, but is in a fair way of re-
covery. It seems that on Saturday ni<!;ht, before
5oin!? 10 bed, they made up a fire and turned the
damper o( the stove, so thai in a short lime
(hereafter, the fitincs must have spread through
their apartment and rendered thein unconscious.
On Sunday about ten o'clock, they were d srover-
ed almost lifeless. Dr T. S. Reed was called in
the afternoon to see the suflcrers, but it was too
\nv<^ »n do :iny eaod in the case of the father.
^phUa^'i^'--. „Jr-^?,.te,Jan23d. , ^^A

"- - Ti„.,„„„,c' The

ch /^^/

Important Discovery in Ventilation.
The London Literary Gazette announces a verj
impQriani discovery in ventilation. The inventor,
Dr Ghowne, has taken out a patent for it. It is
based upon a principle of the syphon, hitherto
unnoticed. It is found that air rushes into the
short leg of the syphon, and out at the long, in-
cessanilv. The application of this principle, to
the purp'oses of ventilation, will suggest them-
selves to every mind. The discovery is one of
great importance, without doubt. Every room,
connected with a chimney, can have an appara-
tus constituting the short leg of the syphon, leav-
ing the chimney ior the long leg.

REPORT ON VENTILATION,

PRESENTED TO THE SCHOOL COMMITTEE, DEC. 30tJi, 1846.

The Committee, to whom the subject of Ventilation
was referred, ask leave to

EEP O RT:

That, during the early part of the present year,
they have visited, and carefully examined, all the
School houses under the care of this Board, in obe-
dience to the Order herewith prefixed.

Your Committee do not deem it advisable or ne-
cessary, to enter upon the discussion or description
of the various systems of ventilation which have been
proposed from time to time, or to consider their
comparative merits. Many of them, no doubt, are
excellent ; and, if properly arranged, must be effi-
cient. But we believe, that the distinguishing ex-
cellence of any method must consist in, and be in
exact ratio to, its adaptedness to meet the peculiar
requirements of each case to which it is applied.
Nor do we think it possible for any plan to succeed,
which does not include the architecture and situa-
tion of the structure to be ventilated, and the num-
ber and necessities of those who are to occupy it.
Nevertheless, a suitable attention to the laws of life,

6 VENTiL.VllON OF

and of the physical agents which are concerned with
it, will always ensure ready indications of the best
course of procedure, and, at the same time, furnish
a basis whereon to found it, which will be sufficient-
ly firm and comprehensive. Your Committee, there-
fore, desire to call the attention of this Board to the
consideration of such general and well-established
Physiological and Philosophical principles, as have a
distinct and intimate relation to the subject of this
Report, or may be useful in its elucidation.

In doing this, there are two things of which they
hope to satisfy the Board.

First. The necessity of a system of Ventilation,
which shall furnish, for all the pupils in the Public
Schools of Boston, at all times, an abundant supply
of an atmosphere entirely adapted, in its purity and
temperature, to the purposes of respiration.

Secojidlij. The entire failure of the measures here'
tofore adopted to accomplish this desirable end.

The function of Respiration is that process, by
whose agency and constant operation, the atmos-
pheric air is admitted to the internal surface of the
lungs, for the purpose of effecting certain changes in
the blood which are as essential to the continuance
of life, as to maintain the integrity of the bodily or-
gans. During this process, the air is constantly los-
ing its oxygen, which is carried into the circulation,
while, at the same time, it is becoming overcharged
with tlie carbonic acid gas, which is continually
thrown off from the lungs by respiration. This effete
and deadly jjoison spreads itself rapidly into all parts
of the room.

" M. Lassaigne has shown, by a series of inves-
tigations, that, contrary to a common opinion, the air
in a room which has served for respiration without

SCHOOL HOUSES. 7

being renewed, contains carbonic acid alike in every
part, above as well as below ; the difference in pro-
portion is but slight ; and where appreciable, there
is some reason to believe that the carbonic acid is in
greater quantity in the upper parts of the room. These
experiments establish the very important fact, that
all the air of a room must be changed in order to
restore its purity."*

LeBlanc — who examined many public and private
buildings, in France and elsewhere — speaking of the
Chamber of Deputies, where sixty-four cubic feet of
fresh air per minute were allowed to each individual,
states, that of 10,000 parts escaping by the ventila-
tor, twenty-five were carbonic acid ; while the quan-
tity of this gas ordinarily present in the atmosphere
is but TfftoT).

Dr. Wyman makes the following remarks on this
point : " Although carbonic acid is a much heavier
gas than atmospheric air, it does not, from this
cause, fall to the floor, but is equally diffused through
the room. If the gas is formed on the floor, with-
out change of temperature, this diffusion may not
take place rapidly. In the celebrated Grotto del
Cane, carbonic acid escapes from the floor, and rises
to a certain height, which is pretty well defined to
the sight on the walls ; below this line, a dog is des-
troyed, as if in water ; above it, he is not affected.
An analysis of the air above and below a brazier has
been made, and it was found equally contaminated,
— the former containing 4.65 per cent., and the lat-
ter 4.5 per cent, of carbonic acid.

" From the experiments of M. Devergie, who has
devoted much attention to the poisonous effects of

* Silliman's Journal, for September, 1846.

8 VENTILATION OF

these gases, it appears, that the heat disengaged
from the comlnistion of charcoal, produces an equa-
ble mixture at all elevations in tlie apartment ; and
this state of things continues as long as the room
remains warm ; but after twelve hours or more, the
carbonic acid sinks, and while that near the ceiling
contains only a seventy-eighth, that near the floor
contains nearly four times as much, or a nineteenth."*

If further proof be needed to establish this posi-
tion, we have other testimony. It is known that a
considerable quantity of vapor is discharged from the
lungs during respiration. With regard to this, Mr.
Tredgold says : " If the air did not contain this mix-
ture of vapor, it would not rise when expelled ; and
we have to admire one of those simple and beautiful
arrangements, by which our all-wise Creator has pro-
vided against the repeated inhalation of the same air ;
for a mixture of azote, carbonic acid gas, and vapor,
at the temperature it is ejected, is much lighter than
common air even at the same temperature. Hence,
it rises with such velocity, that it is entirely removed
from us before it becomes diffused in the atmos-
phere. But as all gaseous bodies and vapors inti-
mately mix when suffered to remain in contact, we
see how important it is that ventilation shoidd be
continual ; that the noxious gases should be expel-
led as soon as generated ; and that the ventilation
should be from the upper part of a room."t

If, to the foul effluvia ejected from the lungs, and
accumulating in an apartment as badly ventilated
as one of our School rooms, be added the fouler mat-
ter thrown into the air from the insensible perspira-
tion of so many individuals, many of whom are of

" Prncticnl Treatise on Ventilation, p. 77.

f Tredgold on Warming and Ventilating Buildings, p. 70.

SCHOOL HOUSES. 9

uncleanly habits in person and apparel, it is appa-
rent, that, in a very limited period of time, the air
in a perfectly close room would become so entirely
unfit for respiration, that, to all who were exposed
to its influence, submersion in water could not be
more certainly fatal.

The terrible effects of continued exposure to car-
bonic acid gas in a concentrated form, have been
graphically described by Howard, in his account
of the Black Hole of Calcutta. Of one hundred
and forty-six persons, shut up in this place, for only
ten hours, without any other means of ventilation
than one small opening, but twenty-six were found
alive, when it came to be opened ; and most of these
suffered afterwards from malignant fevers.

The fainting of feeble persons in crowded assem-
blies, and the asphyxia so often produced in those
who descend into deep wells without suitable pre-
caution, are familiar examples of the same noxious
effects of this poison.

It has been usually estimated, that every individ-
ual, by respiration, and the various exhalations from
the body, consumes or renders unfit for use, at least
from four to five cubic feet of air per minute. This
is probably a low estimate ; but authors of good re-
pute differ considerably on this point. Mr. Tred-
gold's remarks, in this connection, are interesting
and pertinent. " The Physiological Chemists," says
he, " have placed in our hands a more accurate
means of measuring the deterioration of air in dwell-
ing-rooms, than by the best eudiometer; for they
have shown, by repeated experiments on respiration,
that a man consumes about thirty-two cubic inches
of oxygen in a minute, which is replaced by an equal
bulk of carbonic acid from the lungs. Now, the

10 VENTILATION OF

quantity of oxy«?cn in atmospheric air is about one
fifth ; hence it will be found, that the quantity ren-
dered unfit for supporting cither combustion or ani-
mal life, by one man, in one minute, is nearly one
hundred and sixty cubic inches, by respiration only.
But a man makes twenty resj)irations in a minute^
and draws in and expels forty inches of air at each
respiration ; consequently, the total quantity con-
taminated in one minute, by passing through the
lungs, is eight hundred cubic inches."* The other
sources of impurity, which should be considered, will
increase the estimate to the amount above stated.
The amount of vapor discharged from the lungs, and
thus added to the impurities of the air, is said to ex-
ceed six grains per minute. It has also been shown,
that air which has been some time in contact with
the skin, becomes almost entirely converted into car-
bonic acid.t

In estimating the amount of fresli air to be supplied
we ought not merely to look at what the system will
tolerate, but that amount which will sustain the high-
est state of health for the longest time. Dr. Reid
recommends at least ten cubic feet per minute, as a
suitable average supply for each individual ; and
states that his estimate is the result of an " extreme
variety of experiments, made on hundreds of diff"er-
ent constitutions, supplied one by one with given
amounts of air, and also in numerous assemblies and
meetings, where there were means for estimating the
quantity of air with which they were provided." J

These calculations refer to adults ; but the greater
delicacy of the organization of children, and their
feebler ability to resist the action of deleterious agents,

* Treilgold on W'urniing and Veiililaling Buildings, p. GO.
' Cniikshanka makes it twenty-three grains per minute.
\ Illustrationa of Verjtilatjon, p 175

SCHOOL HOUSES. 11

together with their greater rapidity of respiration, de-
mand for them at least an equal supply. Proceeding
upon this basis, and multiplying the amount required
per minute, by the minutes of a school session of three
hours, we have eighteen hundred cubic feet for each
pupil, and for two hundred and fifty pupils — the
average maximum attendance in one of our large
school rooms, — 450,000 cubic feet, as the requisite
quantity for each half-day. The rooms contain about
22,500 cubic feet only : so that a volume of air, equal
to the whole cubic contents of each room, should be
supplied and removed, in some way, ten times every /v^*-*^^ .
three hours, in order to sustain the air in them at
a point which is perfectly healthy and agreeable.
For such a purpose, the present means are so entirely
inadequate, that it was found that the air of a room
became tainted in ten or fifteen minutes. In ordi-
nary cases, four per cent, of the air expelled from
the lungs is carbonic acid. The presence of five or
six per cent, will extinguish a lamp, and with diffi-
culty support life. It is therefore certain, that the
air would become deprived of all its best properties
in one school session.

The very earliest impressions received by your
Committee, in their visits to the school houses, satisf
fied them of their lamentable condition in regard td)
ventilation. In some of them, they found the air so
bad, that it could be perceived before reaching the
school rooms, even in the open entries ; for we no-
ticed that the clothes and hair of the children who
passed us on the stairs were perceptibly impregnated
with the foetid poison. And these circumstances ex-
isted in houses, whose open windows testified, that
the Masters had endeavored to improve the atmos- .
phere by all the means placed at their disposal. To this

K VEXTILA'l'IOX OF

custom, — that of openiiui windows in school hours^ —
the Instructers are compelled to resort for relief; this
expedient being certainly the lesser of two very great
evils. Yet this dangerous and injurious practice
only mitigates the e^■ils of bad air, by creating others.
It produces colds and inflammatory complaints, and
the air still remains impure, offensive, and highly
deleterious ; sufficiently so, to affect the delicate or-
ganization of childhood, to blight its elasticity, and
destroy that healthful physical action, on which de-
pends the vigor of maturer years.

We have referred to some of the more violent and
sudden effects of exposure to air highly charged with
these noxious gases. There are others, which, al-
though more remote and hidden, are not therefore of
less importance. The grave consequences of long-
continued exposure to an atmosphere but a little be-
low the standard of natural purity, although not im-
mediately incompatible with life, can hardly be over-
stated. These effects are often so insidious in their
approach, as scarcely to attract notice ; it is therefore,
the more necessary to provide against them in ad-
vance.

Children, who are confined in the atmosphere of
these schools, soon lose the ruddy and cheerful com-
plexions of perfect health which belong to youth,
and acquire the sallow and depressed countenances
which might reasonably be expected in over-worked
factory operatives, or the tenants of apartments
which are never blest by the cheeiful sun or the re-
iving air.

Although the atmosphere in the different school
houst's varied very much in particular cases, either
owing to the time of the visits, or from the amount
of attention and intelligence of the ^Masters, vet in

SCHOOL HOUSES. 13

none of them was it at all satisfactory ; not one of
them was furnished with any useful or systematic
means of ventilation.

All of the rooms are provided with registers, in or
near the ceiling, ostensibly for the purpose of dis-
charging the foul air, but which are entirely useless.
The openings through the roof into the open air,
where they exist, are so small, as to be quite inade-
quate to relieve the attics ; so that the bad air must
accumulate there, and, after becoming condensed, be
gradually forced back again, to be breathed over by
the same lungs which have already rejected it. The
condition of the apartments, after undergoing a repe-
tition of such a process, for any length of time, can
easily be imagined.*

It may be deemed a matter of surprise, that the
subject of ventilating our school rooms has not long
ago received the consideration necessary to remedy,
or even to have prevented altogether, the evils of
which we at present complain. But these evils have
not always existed. It should be recollected, that
the stoves and furnaces now in common use, are of
comparatively modern date ; and moreover, that the
ample fireplaces which they have displaced, always
proved perfectly efficient ventilators, although, it is
true, somewhat at the expense of comfort and fuel.
But in closing the fireplaces, and substituting more
economical methods of warming, evils of far greater
magnitude have been entailed upon us.

It is evident, that, in order to carry into operation
any complete system of ventilation, there must be
connected with it some apparatus to regulate the
temperature of the air to be admitted, as well as to

* See Diagram, p. 15,

14 VENTILATION OF

ensure its ample supply. Your Committee have ac-
cordingly examined, with much care, this part of the
subject.

A majority of the buildings are furnished with
" hot-air furnaces," situated in the cellars ; the re-
mainder with close stoves, placed in the school rooms
themselves.

In our endeavors to introduce in this department,
the improvements which seemed to us absolutely es-
sential, we have encountered serious difficulties.
Most of the furnaces possess great heating powers,
— indeed much greater than are necessary, if the
heat generated by them were properly economized,
or could be made available; — but, as now con-
structed, they are worse than useless, consuming
large quantities of fuel, and, at the same time, so
.overheating the air which passes through them, as to
deprive it of some of its best qualities, and render it
unsuitable for respiration, although it is difficult to
define, with precision, or by analysis, the changes
which take place in air subjected to the action of
metallic surfaces, at a high temperature.

It has been ascertained, by repeated examinations,
that the temperature of the air, when it arrives at
■^a^" the rooms, through the very small warm air pipes
now furnished, is often as high as 500° and 600"
Fahrenheit. Of course, it is entirely impossible to
diffuse air, thus heated, in the parts of the room oc-
cupied by the pupils. Much of it passes rapidly out
of the windows, which may be open ; the rest to the
ceiling, where it remains until partially cooled, grad-
ually finding its way down by the walls and closed
windows, to the lower parts of the room. The con-
sequence is, that while much more caloric is sent
into the apartment than is requisite, many of the pu-

SCHOOL HOUSEa

pils are compelled to remain in an atmosphere which
is at once cold and stagnant.

A reference to the subjoined diagram will explain
at once, the present state of the Ventilation of the
school houses.

a. Heated air from furnace.

b. Hot air escaping through open window.

c. Cold air entering through open window.

These difficulties are inherent in the structure of
the furnaces ; and they cannot well be obviated, by
any other method than by rebuilding or replacing
them.

The boxes, which admit the cold air to the fur-
naces, are much too contracted ; some of them being
only a few inches square, when their capacity ought
to be nearly as many feet. The air enters the " cold
air" chamber of the furnace, at its top, whence it is
intended to be carried down between thin brick walls,
(which should be cold, but which are often heated to
300° Fahrenheit,) to the lower part of the furnace,
and thence into the " hot air " chamber, and so on
to the rooms above. It is obvious that the " hot-
air " chamber must be heated to a temperature far
beyond that of the " cold air " chamber, in order to

16 VENTILATION OF

compel the air, against its own natural tendencies,
to pass into it with any velocity or volume, and the
very attempt to accomplish this, almost defeats it-
self; as, by driving the fire for this purpose, the
" cold-air " chamber becomes still hotter, so that at
iKst the contest is decided only by the greater calor-
ific capabilities which the iron plates possess over
the brick wall. At any rate, the temperature of the
iron fire pot is frequently raised to a red or even a
white heat^ by running the furnaces in the ordinary
way. This soon destroys them, and they require
consequently to be frequently renewed.

Your Committee arc satisfied, that the present
state of the school houses daily impairs the health of
the pupils and Instructors, and the efficiency of the
schools for the purposes of instruction ; that its
continuance will produce, not only immediate dis-
comfort and disease, but, by its effect upon the con-
stitutions of the children, who must pass in them a
large portion of those years most susceptible to
physical injury, will directly and certainly reduce
the amount of constitutional vigor hereafter to be
possessed by that large mass of our poi)ulation,
which now and hereafter is to receive its education
in these schools.

With regard to the expenditure necessary- to com-
plete the improvements which your Committee re-
commend, they are of tlie opinion, that the alarming
evils referred to in this Report, may be at once, and
entirely and permanently removed, at an average ex-
pense of two hundred and fifty dollars for each
school house, now built. And by availing ourselves
of some recent improvements, which have been
made in this Citv, in the fonn and construction of a

SCHOOL HOUSES. 17

part of the necessary apparatus, we hope to reduce
its cost, and at the same time increase its efficiency.
But the Committee have no douht, from actual
experience of the effects ah-eady produced by the
experiments which they have superintended, in two
school houses, that all the expense of any alterations
which may be required, to warm and ventilate our
school houses upon rational principles, and in a tho-
rough manner, will be more than saved to the City,
in two or three years, in the item of fuel alone, if
the system which they propose is adopted, and faith-
fully carried into operation.

[The Eeport then details some experiments upon
the Eliot School house, and describes the plans
adopted to ventilate the Endicott School house.
These can be omitted here, as all their essential
features are comprised in the diagrams which illus-
trate the final Eeport. The following drawing is
given to show the mode adopted for introducing and
supplying warm air to the houses and apartments,
such as recitation rooms, primary school rooms, &c.,
which we found heated by close stoves?\^

The drawing (page 18) exhibits a section of a stove,
enclosed by an outward casing of sheet iron, or tin,
so as to make a large chamber around it, into which
the fresh air may be admitted and warmed. The
arrows show the course of the air through the stove.
It is supplied from an air-box opening under the
inner cylinder and connecting with the fresh air by
means of an aperture cut through the outer wall of
the building. The suspended top regulates the tem-
perature, and gives a lateral direction to the warm air.

VENTILATION OF

The Committee propose the following as an outline
of the best general plan for warming and ventilating
the school houses.

1. The air must be taken from a pure source and
from the higher parts of the building, if any impuri-
ties are found to exist near the surface of the ground.

2. In order to ensure a constant and abundant
supply, the air shaft when carried above the building
must be surmounted with a cowl or hood of some
kind, with its mouth turned towards the wind.

3. The fresh air should in all cases be carried
entirely beneath the furnace. If the cellar is wet
and the situation low, the underground culvert, or
channel, should be of brick, laid in cement.

4. The furnace chamber should be so large that
it can be entered at any time, without the necessity
of taking down walls, for the purpose of repairs, or
to observe the temperature. A large earthen pan
for the evaporation of water should not be omitted.
This should be kept ])erfoctly clean, and the water
required to be frequently cliauged.

SCHOOL HOUSES. 19

5. A thermometer should be constantly at hand,
and the temperature in the ivarm-air chamber should
never he allowed to exceed that of boiling water. A
still lower temperature is often desirable. If this
point is secured, the hot air can be conducted with
perfect safety into any part of the building.

6. The openings for the admission of the warm
air into the rooms, should be as numerous as possi-
ble. The long platform occupied by the teachers,
might be made an excellent diffusing surface.

7. Openings of ample size must be made in the
highest points of the ceiling, to be connected at the
top of the roof with a turn-cap or louvre, the former
being always surmounted with a vane. It is better
that the ceiling should be perforated at its centre,
and there is no objection to running the ventilating
shaft, at first, horizontally, if the perpendicular and
terminal portion of it is of considerable length.*

8. It is well to have a power of some sort, ivithin
the apparatus at its top, for the purpose of compelling
constant action and of increasing the force of the
apparatus, whenever the state of the weather, or the
crowding of the room, renders it necessary. For this
purpose, the most convenient and economical means
are furnished by a gas burner, an argand lamp, or a
stove ; and one of these may be in constant readiness
for use, when neither the velocity of the wind, nor the
low temperature of the external atmosphere, are
sufficient to produce the desired effect.

9. All the openings and flues for the admission of
pure air, and the discharge of the foul air, should be
of the maximum size ; that is, they should be calcu-
lated for the largest numbers which the apartment is
ever intended to accommodate.

* See page 31 of Final Report.

90 VENTILATION OF

10. Valves must be so placed in the flues as to
be easily regulated without leaving the rooms into
which they open.

11. The best average temperature for school-
rooms, is from 64^ to 68° Fahrenheit ; this range
including that of the healthiest climates in their best
seasons.

12. For the purpose of summer ventilation, and
for occasional use in moderate weather, fireplaces of
good size may be constructed in the new houses.
They should always be double, and furnished with
chambers communicating with the open air.

13. Each story of the building must be warmed
by a Furnace or Stoves, appropriated exclusively for
its own use.

Before concluding this Report, your Committee

cannot avoid expressing the confident belief, that a

\ suitable consideration of the evils, whose existence

i they have proved, is only necessary to ensure their

speedy removal.

It has been already shown, that healthy blood is
essential to the proper vital action of the organs of
the human body, and that the healthy condition of
the blood, depends entirely upon the act of respira-
tion ; that, t o breathe air d e])ri yed of its oxy gen,, or »
containing any thing which prevent s the necessary
changes in the blood, is to_bi -eathe disease and death .

We can subsist without food, for days, or even
weeks. We might spend our whole lives, under
some circumstances, without clothing or shelter; and
yet, while almost all the energies of civilized society
are exerted to obtain these things, in their various
forms of comfort or luxury ; with a most surprising
disregard of the dictates of common sense, and a

SCHOOL HOUSES. 21

want of discretion which is no where else exhibited,
we exclude from our best houses, by every means in
our power, that vital fluid, without which no respi-
ratory being can exist for a single hour.

HENEY G. CLAEK,
EDWARD G. LOHING,
CHAELES BEOOKS.

Boston, December 30, 1846.

CITY OF BOSTON.

In School Committee, December 30, 1846.

Ordered, That the Committee on Ventilation be
and hereby are directed to adapt to each School
room of the Common Schools such apparatus, if any,
as may be required to secure to them proper venti-
lation in Winter and Summer, and make such alter-
ations and arrangements of the furnaces as may be
required.

Attest, S. F. McCleary, Secretary/.

9i VENTILATION OF

In order to obtain the requisite means for carrying
out the intentions of the School Board, the Commit-
tee on Ventikition memorialized the City Council.
The subject was referred to a Special Joint Commit-
tee, who made thereupon a Ilq)ort, as follows :

The Joint Special Committee to whom was re-
ferred the petition of the Sub-Committee of the
School Committee, asking an appropriation to im-
prove the ventilation of the Grammar School Houses,
have attended to the subject, and ask leave to

REPORT.

The petitioners appeared before the Committee,
and set forth the great importance that attaches to
the subject of having pure air where great numbers
are congregated — especially where those masses are
constituted of children. They stated that in two of
the Grammar School Houses, they had caused a ven-
tilating apparatus to be constructed, which had been
in operation nearly a year.

The experience of this period authorized them to
state, first, that the air of the rooms had been greatly
improved, — and in the second place, that the expense
of warming the rooms was diminished one half, be-
sides a great saving in the consumption of the cast-
ings of the furnace.

Such were the representations of the petitioners.

In order to be fully satisiied, the Committee visited
the Endicott School, where the apparatus was in
operation. The day was exceedingly wet and disa-
greeable, and yet the air of the rooms was found in
an unobjectionable condition. The masters fully sus-
tained the representations of the petitioners ; and

SCHOOL HOUSES. 23

from their statements, as well as from their own ob-
servations, the Committee were satisfied of the bene-
ficial efiects of said apparatus.

In order, however, to have a more full investiga-
tion of the matter, the Committee, on a subsequent
day, visited the Johnson School and the Boylston
School. The day was dry and cold, and they found
the air in the Johnson School in a tolerably good
condition. This is a girls' school; and it is well
known that the pupils in such schools are neater,
and attend in cleaner and more tidy apparel, than
the pupils in the boys' schools.

In the Boylston School, however, the Committee
found the air very disagreeable and oppressive ; and
they could not but feel the importance of executing
some plan of relief.

From the earnest representations of the petition-
ers, and from the result of their own examination,
the Committee are of the opinion that the prayer of
the petitioners ought to be granted ; and they there-
fore recommend the passage of the following order ;
all which is respectfully submitted.

BILLINGS BEIGGS, Chairman.

Ordered^ That the sum of Four Thousand Dollars
be appropriated for the purpose of improving the
ventilation of the Grammar School Houses — the
same to be expended under the direction of the Joint
Committee on Public Buildings — and be chai'ged to
the appropriation for School Houses.

In Common Council^ Jan. 21, 1847.
Passed.

Sent up for concurrence.

GEO. S. HILLARD, President.

In the Board of Aldermen, Jan. 25, 1847.
Read and concurred.

JOSIAH QUINCY, Jr. Mai/or.

FINAL REPORT, ETC.

In School Committee, December' 9, 1847.
The Committee upon Ventilation respectfully

REPORT:

That in obedience to the order of this Board, and
in pursuance of the plans laid before it in a former
Report, your Committee have diligently applied
themselves to the duty of ventilating the School
Houses — a labor, whose difficulties, could they have
been fully anticipated, might have prevented its ac-
complishment, at least by the members of this Com-
mittee. Although the members of the building
Committee of the City Council have personally ex-
tended to us every reasonable courtesy, yet we can-
not avoid the impression that the provisions of the
Charter which deprive this Board of the control of the
plans of the School Houses were framed with a very
unwise disregard of the best interests of the Schools.

But notwithstanding the intrinsic difficulties of
this undertaking^ increased as they have been by the
causes last named, your Committee cannot deny
that it is with much satisfaction they now announce
its completion. For we think it is no more than
just to express our sincere opinion that the Grammar
School Houses of Boston are now in a better condi-
tion, in respect to their ventilation, than any other
public Schools in the world.

We have said that the work was complete. It is
so substantially — for although many things still re-
quire to be done, in order to make every house in

26 VENTILATION OF

all points equal with the best, yet, with the examples
we have given, and the plans and specifications we
shall submit, accompanying this Report, it is a mere
mechanical work, as time and opportunities offer, to
make each one in all points all that can be desired.

The plans, to which we refer, have been adapted
in various ways, and with a variety of apparatus, as
the circumstances in each case seemed to require, to
sixteen Grammar School Houses, the buildmg occu-
pied by the High and Latin Schools, and besides
these, to twenty-five large rooms used for Branch
or Primary Schools. To all of these we have caused
to be affixed the necessary flues, tops, and other ap-
paratus for discharging the foul air ; and they re-
quire nothing more for that purpose. We have al-
tered, enclosed, or rebuilt, twenty-one stoves and
furnaces, and set and supplied with the ducts, valves,
&c., twenty-six of the new ventilating stoves, herein-
after described. A few houses still require stoves or
furnaces or alterations of the same, of which a list
is herewith appended.

The diversity of arrangement and the modifications
in our plans into which we have been compelled by
circumstances, have had their advantages, and ena-
bled us to arrive at the best results, and to satisfy
ourselves entirely in regard to the particular set of
apparatus which we can recommend with confidence
for future use as decidedly the most effective and
convenient.

We have therefore furnished drawings and specifi-
cations of the set of apparatus wiiich we recommend.

Furnaces. — The only Furnaces belonging to the
Scliool Houses which we have thought worth re-
building are those of ]\Ir. Preston. They are very
substantial, require but little repairing, and are easily
managed. They are open to sufficient objections.

SCHOOL HOUSES. 2T

however, we think, to make it undesirable to furnish
any more where new ones are to be supplied ; and
they are simply these : The whole radiating surface
is of heavy cast iron : it is therefore slow in becoming
warmed so as to affect the air chamber ; and the fur-
naces, for the same reason, are not economical as con-
sumers of fuel. The fire-place is of brick, and in this
respect it is very much superior to most other fur-
naces in which the iron fire pot itself is made the
principal means of heating the air.

The other Furnaces which have been in use in some
of the houses are so objectionable, on account of the
frequent bursting of their pots and the escape of the
deadly gas into the air chamber, as well as for other
reasons, that we have thought the matter of sufii-
cient importance to be made the subject of a special
communication to the Committee of Public Buildings.

Your Committee have made themselves acquainted
not only with all the Furnaces which have been man-
ufactured in this place, and its neighborhood, but
with all those which have been exhibited here recent-
ly. Most of them show much ingenuity of contri-
V9,nce and excellence of workmanship ; but are all,
so far as we can judge, inferior in many respects, to
the one, a model and plans of which we now exhibit,
and recommend as superior to all others.*

It is simple in its structure, easily managed, will
consume the fuel perfectly, and with a moderate fire.
It is fitted for wood or coal. The fire place is broad
and shallow, and is lined with soapstone or fire-brick,
which not only makes it perfectly safe and durable,
but modifies very materially the usual effect of the
fire upon the iron pot.

The principal radiating surfaces are wrought iron,
of a suitable thickness for»service, while at the samis

* Invented by Mr. Chilson. (See page 2S.) Also, Appendix, D.

VENTILATION OF

time the heat or the smallest fire is communicated
immediately to the air chamber. The mode of set-
ting this Furnace we consider essential ; more espe-
cially the plan of admitting the air to the furnace at
its lowest point, as it then rises naturally into the
apartments above. This process commences as soon
as the temperature is raised even a single degree.
The outer walls remain cold ; the floor above is not
endangered, and the whole building is rapidly filled
with an atmosphere which is at once salubrious and
delightful. The proprietor of this Furnace very lib-
erally offered to make such improvements upon its
original forai as your Committee thought necessary
or desirable, at his own cost. He has also allowed
one to be set in the Mayhew School House under our
direction, where it may be seen in contrast with one
of the old furnaces set in the old way.*

Sertion of Old Furnace. Sec p. 15.

r|*nv«./^^ '^'>^>a •* Since the nbove w.is lend, the p r o jui'-tcr.-i of the old furnace have re-
placed the old pot, (wiiiih had cracked) and enlarged the air box to three

times its former bIzs.

SCHOOL HOUSES.

The cold-air channel to this furnace is four feet by
nearly tivo — and the warm-air flue, which is of brick,
lined with cement, is ahout three feet, by one and a
half (See Appendix D.)

For the -houses which we found without the Hot
Air Furnaces, as also for the Eecitation and other
single Eooms, the invention of a Stove which should
answer the same purpose became essential. One was
therefore contrived ; and having been found in its
earlier and ruder forms to be of great utility, it has
since been improved in its appearance, as well as in
the convenience of its management.

Elevation and Section of the Ventilating Stove.

Elevation.

Section.

These Stoves are composed of two cylinders, the
inner containing a fire chamber, which is lined with
soap stone or fire brick, while the outer constitutes a

30 VENTILxVTION OF

chamber for warming the air, which is introduced in-
to it l^encatli tlie inner cylinder, from an air box di-
rectly connected with the external atmosphere.
They possess the following advantages : —

1. They are in fact furnaces^ having distinct and
capacious air chambers.

2. They insure, when properly set, that supply of
fresh air, which is indispensahle to the proper ventila-
tion of any apartment.

3. The Regulating Distributor, which is movable
or fixed, as may be desired, determines Mith great
accuracy the amount and temperature of the admit-
ted air.

4. The outer cylinder is never hot enough to bum
the person or clothing, or to be uncomfortable to
those who are situated in its immediate vicinity.

5. They are constructed with the utmost regard to
efficiency, durability, compactness, and neatness of
appearance.

These Stoves have been furnished to the Schools
whenever your Committee have required their use,
and at manufacturers' prices, without any profit what-
ever to the Inventor and Patentee.^

They may be used with advantage in the largest
rooms, when the cellars are unfit for Furnaces, or
when it is preferred to have the fire in the room it-
self The Johnson, Wells, Ilawes, and Winthrop
School houses are warmed entirely by them.

Ventiducts. The discharging ventiducts have been
made in various ways — some of wood, some of metal,
and others of " lath and plaster." Some have opened
at the ceiling only, und in but one part of the room,
while others have been equally divided at opposite
sides of the apartment. Our rule is this : — If the
Heating Apparatus is at one end of an oblong room,

SCHOOL HOUSES. 31

the ventiduct is placed at the opposite. If the store
or furnace flue is at the middle of the longest side,
the ventiducts are placed at each end, and are of
course reduced to one half the size of the single one.

The hest manner of constructing them is shown by
the drawings, and described on page 33.

There is great economy in carrying the boxes to
the floor in all cases. In this way the room can be
kept warm and the air pure in the coldest and most
windy days.

The registers at the top and bottom can be used
separately or together, as may be desired. (See Ap-
pendix A.)

It is necessary and advantageous to apply some
kind of cap or other covering upon the ventiducts
where they terminate above the roof It is necessary
as a protection from the rain and the down blasts of
wind, and it is also very advantageous to be enabled
in this way to avail ourselves of the power of the
wind to create an active upward current. We used
at first the turncap or cowl invented by Mr. Espy,
and with satisfactory results. It is undoubtedly the
best movable top known ; but is noisy and somewhat
liable to get out of working order. These objections
to the movable tops have long been known, and va-
rious stationary tops have been invented and have
been partially successful. An improved Stationary
Top, or Ejecting Ventilator, as it is called, has been
invented during the past year by Mr. Emerson, and
is the apparatus to which we referred on page 16,
of our first Report. It is shown in the drawing, and
consists of a frustrum of a cone attached to the top
of a tube, open in its whole extent, and surmount-
ed by a fender which is supported upon rods, and
answers the double purpose of keeping out the rain

VENTILATION OF

and of so directing or turning a blast of wind upon
the structure, as that in whatever direction it falls,
the effect, that of causing a strong upward draft,
will be very uniform and constant.

EJECTING VENTILATOR

lNJErTI\(; Vn\Tll,ATOR.

Being satisfied that this Stationary Ejector pos-
sessed all the advantages of the best tops hitherto
known, without the disadvantages of either of them,
we have adopted it for several of the houses last ven-
tilated, and find it in all respects satisfactory. We
therefore recommend it for general use.

The Injector may generally be dispensed with, but
in situations unfavorable for introducing air, it may
be sometimes found convenient, or even necessary.

SCHOOL HOUSES.

iiiiiiii!iiiiuiii:ii]i;i

Elevation of Ventiducts.

The discharging ventiducts should
be situated at the part of the rooms
most distant from the stove or reg-
ister of the furnace, and should al-
v^ays, if possible, be constructed in
or upon an interior wall or parti-
tion, and an outer brick wall must
if possible be avoided. They should
be made of thoroughly seasoned
sound pine boards, smoothed on the
inner sides, and put together with
two-inch iron screws. The outside
finish may be of lath and plaster,
or they may be projected back-
wards into a closet or entry, as
^^^ shown in the Section.* They must
be carried entirely to the floor, and
should be fitted at the top and bottom
with a swivel blind, or register,
whose capacity is equal to that of
the ventiduct into which it opens.
This blind may be governed by
stay rods or pulleys. The eleva-
tion in the margin gives a view of
the ventiducts for a building of three
stories, and shows the best mode
of packing them, so as to avoid in-
juring the appearance of the rooms-

These ventiducts must be he^^t
entirely separate to the main dis-
charger at the roof, as any other
arrangement would impair or des-
stroy their utility.

fU^

* See page 35.

.^. UfV^^Ji^

>%b^

VENTILATION 0¥

Xlf

fn:

V^^

n. Cold nir duels.
IT. Smoke flue*.

The size of the ventilators
and ventiducts must corres-
pond to the capacity of the
room, and the number it is
intended to accommodate.

A room containing sixty
Scholars is found to require a
discharo-infi: duct of fourteen
inches in diameter./ A room
for one hundred Scholars re-
quires the tube to be eighteen
inches ; and a room for two
hundred Scholars requires it
to be twenty-four inches.

The fresh air ventiducts
should exceed iJicajMcifj/ those
for carrying off the impure
air by about fiftj/ per cent. ;
so that there will then always
be a surplus or plenum sup-
ply, and the little currents of
cold air which press in at
the crevices of the doors and
windows will be entirely pre-
vented.

The Section shown in the
margin exhibits a very con-
venient mode of bringing the
cold air to the ventilating
stoves in a three story build-
-insr in connection with the
smoke flues.

• • • . ^ " / '* ^ •

SCHOOL HOUSES.

The following Section and Plans (See page 36)
exhibit at one view an example of a building of two
stories warmed and ventilated by the apparatus and
in the manner recommended.

Jl. Chilson's Furnace.

B. The Boston School Stove.

C. Emerson's Ejector.

a. Cold or Fresh air ductg,

h. Warmed air ducts.

c. Impure air ducts.

d. Smoke flues.

VENTILATION OF

Plans of first and second floors. The letters on
the plans correspond to those in the Section.

FIRST FLOOR.

SECOND FLOOR.

A. Furnace.

a. a. a. Fresh air ducta.

b. b. b. Warm air registeri.
e. e. c. Impure air ducts.

SCHOOL HOUSES. 37

In the first Eeport it was estimated that the sum
of j^250 would be sufficient to ventilate each School
house. Our experience has justified this estimate —
but we have found in the basement stories of these
houses Branch or Primary Schools to the number of
twenty-five, all of which have been ventilated. Al-
lowing ^100 each for these, or charging oiF the cost
of supplying and repairing heating apparatus, which
we have been obliged to do, or discontinue our
labors, and we shall still be much within our estimate.
There are a few furnaces which require altera-
tions, and one house, the Franklin, has not been
ventilated, so that we think ^750 more should be
asked for in addition to the ;^2750, the sum which
is required to settle the bills for ventilating the rooms
named above.

We have appended to this Report directions for
the management of the Stoves, Furnaces and Venti-
ducts, to which the attention of the masters of the
Public Schools is requested, in conformity to the
rule of this Board which requires their attention to
the Ventilation of the School houses under their
care.*

We request the passage of the accompanying or-
ders.

All which is respectfully submitted.

HENRY G. CLARK,
EDWARD G. LORING,
CHARLES BROOKS.

,«, * See Appendix A.

CITY OF BOSTON

In School Committeey Dec. 9, 1847.

The Committee on Ventilation made a Report —
to which was subjoined the following orders, viz :

Ordered^ That the modes of ventilation and heat-
ing specified in the foregoing Report, be and hereby
are recommended to the City Government for the
use of the Boston Schools.

Ordered., That the City Council be requested to
make an appropriation of ^3500 ; the said sum, or
such part of it as may be necessary to complete the
Ventilation of the School houses, to be subject to the
order of the Sub-Committee of the School Committee
upon the Ventilation of School houses.

Read, accepted, and the orders passed by a unani-
mous vote, and 500 copies ordered to be printed.

Attest, S. F. McCleary, Secretary.

APPENDIX.

Rules relative to the use of the Stoves, Furnaces and
Ventiducts.

1. To warm the room. Close the upper, and open the lower
registers of the ventiducts ; close the upper door of the stove or
furnace and open the lower door.

2. After the room is warmed. Eaise the distributing top of
the stove from three to six inches ; close the lower door of the
stove or furnace and open the upper door ; open all the registers
of the ventiducts about half their width.

3. If the room is too warm. Open the registers full width,
and raise the cover of the stove, keeping the upper door of the
stove or furnace open, and the lower door closed.

4. If the room becomes too cool. Close the upper registers, (for
a short time only ;) close the upper door of the stove and open
the lower door ; drop the cover down within two inches of the
sides.

5. Never close the top of the stove entirely down, while there
is any fire therein.

6. At night, on leaving the room, let the cover of the stove
down within one inch of the sides ; close the lower door of the
furnace or stove and open the upper one ; place all the registers
open about half their width.

7. The valves in the cold air ducts must never be entirely
closed while there is any fire in the stoves or furnaces to which
they lead.

8. TTie windows must not be opened to cool the room ; but the
fire should be diminished, or the principal door may be opened for
a short time.

40 APPENDIX.

B. See pages 14 and 27.

The following extracts are made from a note furnished by Dr.
Wjman* to your Committee at their request, and for which they
desire to express to him their obligations.

The answer to the first question, as quoted here, is a mere
synopsis of that given, but is in the words of Dr. Wyman. The
others are in full.

" Question I. The chemical changes produced in air exposed
in the chamber of a hot air furnace to an iron surface at a red-heat
(800«— lOOO'T.)?

"The changes produced under the circumstances stated in
the query would be, the dryness, and the products of the more or
less perfect combustion of animal or vegetable matter — carbonic
acid and the other constituents of smoke.

" Question II. Would there be any changes in such air which
would render it injurious to the health of persons who depended
upon it to supply their lungs for respiration ?

" The dryness would undoubtedly be injui'ious and produce many
unpleasant sensations, the most prominent of which would be dry-
ness of the lips and skin, and inflammation of the eyes. The pro-
ducts of the combustion of the inpurities of the air, if in sufficient
quantity, would produce the usual effects of carbonic acid gas,
head-ache and drowsiness ; the other products would produce irri-
tation of the eyes, nose and lungs.

" Question III. The consequences of letting into the air cham-
ber of a furnace large quantities of the gases produced by the
combustion of anthracite coal ?

" These consequences must be injurious in proportion to the
quantity of the gases admitted ; they are deadly poisons ; and
when mingled with the air passing through the furnace and as-
cending to the apartments which it supplies cannot but be injuri-
ous to those whose lungs they enter. Not long since a man and
boy in Salem lost their lives from entering a room into which the
gases from burning anthracite had been driven by the wind. Too
much care cannot be taken to prevent the escape of such gases
into the air-chamber.

" I am very respectfully,

" Your obedient Servant,

"MORRILL WYMAN.
« Cambridge, Nov. 19, 1847."

* Author of '• Practical Treatise on Ventilation."

APPENDIX. 41

The following note has been received from Mr. Hammond, a
Master Mason, who has had more experience in repairing and
setting Furnaces in the Boston School Houses than any other per-
son.

" Sir,

" In compliance with your request, I submit to you what
has come under my observation respecting the use of cast iron
Cylinders (fire pots) in furnaces.

" In the winter of 1845, I was called to put in two new Cylin-
ders at the Mather School House. Last winter, another was re-
quired ; and now it is necessary to put in two more.

" At the Dwight School House, in January, 1847, I set two
new Cylinders, and before the expiration of the winter they were
not fit for use.*

" The expense of a new Cylinder averages about *14.

" I remain, sir,

" Yours, with high respect,

"J. HAMMOND.

''Nov. 15, 1847."

' See pages 16, 27 and 28.

Extracts from a report on the Mayhew School Furnaces, made
to the School Board, by J. M. Wightman, Esq.

" The furnace of Messrs. Bryent & Herman is entirely of cast
iron — the fire pot is very thick, and armed upon the outside with a
number of projecting points to radiate the heat. The cold air box
and hot air tube are much smaller thap in Mr. Chilson's, and as
the air is admitted near the fire pot, which is generally red hot,
the room is warmed by the diffusion of a comparatively small
quantity of highly heated air passing into it.

" The furnace of Mr. Chilson is of thick plate iron, having a more
shallow fii'e pot of cast iron, lined with soap stone, which efFect-

* The Furnaces here referred to have been «lisplaced by order of the
Committee on Public Buildings.
6

42 APPENDIX.

ually prevents its becoming red hot. The air is let into the fur-
nace chamber, and from thence to the School room, in sufllcient
volume to supply the whole domaiul of the School for fresh air,
the air boxes being much larger than in any other furnace. By
this arrangement, an immense quantity of warmed air is constantly
passing through the School room, and the rapidity with which the
air is changed, and an equal temi)eraturc kept in the School, are
worthy of notice.

'' On Monday, the 27th instant, the weather being very cold, tlie
effect of the two furnaces in warming their several rooms was
very apparent. When the School commenced at 9 o'clock, the
temperature of the upper I'oom, warmed by Mr. Chilson's furnace,
was 68°, while that of the room warmed by the furnace of Messrs.
Bryent & Herman was at 55°. Both the fires were made at the
same time, and had been burning with a full draft. Mr. Chilson's
furnace wjis slightly red on the top ; but as the School was suffi-
ciently warmed, the draft of this furnace was shut off, while that
of Messrs. Bryent & Herman was kept on during the morning to
procure the necessary heat.

" Without entering further into a comparison of these two fur-
naces, the Committee would state that they fully concur with the
views of the " Committee on Ventilation," in giving the preference
to the furnace constructed by Mr. Chilson — and among other
reasons, because experience has shown that there is no danger of
the fire pot being broken or destroyed, so as to let the noxious gas
from the coal into the afr chamber — that they believe plate iron,
sudiciently thick to be durable, will more rapidly transmit the
lieat of the fire than cast iron, which must be much thicker —
and from their observations, the room is warmed much quicker —
the purity of the air is greater — and the Ventilation is more
perfect than with the other."

APPENDIX.

Elevation of Mr. Ghilson's Furnace referred to on page 27.

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