14^ 
FURNACE. 
well, or other convenient place ;) or by a tube, from an 
open cittern or refervoir, wiiofe height, aboVe the faid 
clofe refervoir, is fo high, that the water therein may be 
more than fiifficient to counterbalance the ftrength of tlie 
fleam in the clofe refervoir and boiler. The above-men¬ 
tioned tube has a cock or valve, to let the water into the 
clofe refervoir, or boiler; which cock is regulated by a 
float, or other contrivance. The water in the clofe refer¬ 
voir is made boiling hot, by placing the faid refervoir 
over the vents or chimneys of tlie furnace. The cells, or 
other contrivances, are fupplied with water from within 
the boiler by a fmall pump, placed within the boiler, by 
-t^ hich the water is raifed into a kind of open refervoir, 
v\ ithiii the boiler; from which it is conveyed, by tubes, 
or anen aquedufts, to thofe parts where it is wanted. 
The rod or fhaft of this pump, which adbuates its bucket 
orpiftoii, pafTes through a packed collar, in the centre of 
the boiler’s cover. Or, inflead of a pump, the water 
within the boiler is conveyed into the cells, or other con¬ 
trivance, by a kind of fpoons, or other fmall vedels, 
placed at the extremity of fmall pieces of iron, or other 
metal, cfofs-wife, or in a ftar-like pofition, where they 
are to adt as types. From the centre of thefe fmall pieces 
of ifon, where they crofs each other, is a rod or (haft, the 
lame as the pump, whereby the ftar-like arrangement of 
fpoons, or other fmall velfels, are made to defeend and 
afeend. By their defeent they are filled with water; and 
in their afeent they are emptied into the cells, cavities, 
aquedufts, &c, their tails or types ftriking againft a kind 
ot rim or hoop, or other contrivance, for that purpofe. 
The height of the water in the boiler is adjufted or regu¬ 
lated by a common balance-float, or other contrivance, as 
in cominon boilers belonging to fteam-engines. If the 
water in tlie boiler becomes too high, or too much in 
quantity, it is to be diminiflied by ftraightening tlie cocks 
or valves ot the tubesdefeending from the refervoir which 
lupplyit: and if the water is too low, they nut ft be 
widened. And, in cafe the water is much too high, 
(through inattention,) it is to be diminiflied by opening a 
imall cock or valve, placed near the bottom of the boil¬ 
er, or by means ot a fyphon, with its cock or valve. If 
the fize of the boiler is very large, the quantity or force 
of Ileam therein may be increafed by raifing its bottom 
ci'iicave next the fire, fo that it becomes conical, broad 
at its bahs, (viz. about two-thirds of the diameter of the 
boiler’s bottom,) and terminating at its apex in a fmall 
tube, pafling through the cover of the boiler, fo as to give 
the heat a little'vent, and terminating in the cavity under 
the clofe refervoir. 'I'he above contrivance may either 
be conical, pyramidical, angular, &c. according to the 
ftiape of the boiler ; around which are placed cells, cavi¬ 
ties, aquedmfls, tubes, &c. the fame as thofe round the 
inner extremity of the boiler, and I’upplied with water 
either from within or without the boiler, by the fume 
pump, or refervoir, placed a fufficient height above the 
boiler, as above obferved. 
“ Steam, produced by means of the above-mentioned 
philofophical boiler, is applicable to fteam-engin'Cs, and 
other mechanical purpofes, and to various branches of 
pharmacy, by it.s being admitted into double pans, Hills, 
or other proper velfels. The furnace in which the philo- 
lophical boiler is fixed, is of the fame ftiape as the boil¬ 
er, and about four or five inches,- more or lefs, atcording 
to the lize thereof, wider in diameter; fo that the boiler 
may liang therein by its top or rim, leaving a kind of ca¬ 
vity, or narrow flue, for tlie heat to a£l: uniformly round 
the whole of the boiler to its top or rim. From the above 
flue the heat is to afeend, by four or more flues or chim¬ 
neys, in oppofite directions, clofe by the top or rim of 
the’ooiler. Thefe flues orchimneys are to incline arch- 
wife over the top of the boiler; where, meeting, they are 
to form an opening or cavity, in which the clofe or under- 
moft refervoir is to be hung; from which the heat is to 
afeend by three or more fmall flues or Vents, placed iu 
an angular or oppofite diredlion, clofe by the rim or top 
of the refervoir, until they rife above it, w here they are 
to meet, and form one common chimney. Theafli-hcle 
and fire-place are made fo that the air may not enter in 
at the front, or on one fide of the alh hole only, as is 
common ; but in different directions, fo as to meet under 
the centre of the fire, which is to be directly under the 
centre of the boiler’s bottom. Where the furnace is ufed 
as a ventilator, there need only be one opening in the 
front of the afti-lioie, which muft have a door, the fame as 
the fire-place ; both of which are to (hut as clofe as pofli- 
ble, to prevent the accefsofair; the fire being wholly 
fupplied therewith by tubes in difi'erent parts of the alh- 
hole, w ith their ends inclining, to prevent the allies, &c. 
from entering. The lower ends of thefe tubes join a, 
larger tube, at the outfide of the afli-hole ; the lower end 
of which terminates in the pit, mine, &c. where it rs di¬ 
vided into a number of fmaller tubes, extended to diffe¬ 
rent parts thereof, fo as to attraCf or draw air and va¬ 
pours therefrom ; a cock or damper being placed near the 
top of the large tube, to regulate the airneceiTary for the 
fire. It may at times be neceffary to open the door of tlie 
afti-hole a little, to aftift in fupplyiiig the fire with more 
air. If the engine, to which tlie above philofophical 
furnace and boiler are applied, raife a confiderable quan¬ 
tity of water, the faid water is made to aftift in the act of 
ventilation, by letting it into a clofe veffel, having three 
tubes from its upper part; one to let in the water from a 
refervoir, into which tlie engine has raifed it ; another to 
let out the air; and the tliird, which defeends into the 
pit, mine, &c. to draw air and vapours tlierefroni; alfb 
another tube, from its bottom, to let out the water ; each 
of which tubes lias a cock. Suppofe the above veffel 
empty, and the cocks clofed : open the cocks of two of 
the uppernioft tubes, viz. that for letting in the water 
from the refervoir, and the other for letting out the air, 
and the water will enter the veffel, and difeharge the air 
by the other tube. When the veffel is full of water, clofe 
the cocks of the two tubes laft mentioned, and open tliofe 
of the otlier two; fo will the water run out of the veffel, 
which will be filled with air and vapours, from the pit, 
mine, fee. The above cocks are opened and doled by 
the affioii of the engine, or otherwife ; hence, by two or 
more of the above veffels, aconftant and regular difeharge 
of air and vapours is effected. Where the water, railed 
by the engine, is not employed in the att of ventilation, 
it may be applied to the following adtuaiing wheel, of a 
kind of tubular Gonftrudtion, as follows: A tube of cop¬ 
per, or other fubftunce, wliofe diameter and length is ac- 
cording to the quantity of water raifed and the height of 
its fall, being widef't at its top, to receive the water as it 
(lands perpendicular on the point of an axis, paffing 
through its centre. Tlie bottom of the (aid tube is, to¬ 
wards its extremity, cut into a number of divifions, or 
kind of fans, refembling the fly of a fmoke-jack, or com¬ 
mon ventilator, placed in windows, doors, &c. The W’a- 
ter pafling through the openings, betv. een the fans, canfes 
tlie tube to have an horizontal motion. Above the tube, 
on its axis, is a (mail wheel, applicable to pumps, or 
any other devices which require motion.” 
A very ingenious method of applying an elementary or 
pliyfical power to blaft furnaces, has been lately fuggefted 
by Mr. Robert Hindniarfh, of Walworth, near London; 
for which he obtained the king’s piatent, and lets forth his 
invention as follows : “ It is well known that ilie pveffure 
of water and other fluid bodies, in any containing veffel, 
is in proportion to the altitude of the fluid, without any 
regard to the quantity. Thus, if a cylindrical or other, 
wife figured veffel, whofe bottom, for example, is three 
feet in diameter, have a clofe top, with a tube twenty feet 
high fitted into it, and the veffel and tube, wlien tull, 
contain only one pint of water, which weighs only one 
pound, yet the preffure of this water upon the bottom of 
the faid veffel, will be equal to 10737 lb. which is' the 
fame 
