3Q2 F I 
top at pq: rs is a ferrule, nailed round the tube. The 
head and pipe are fo nearly fimilar to thofe of the pump- 
engine above-defcribed, that they need no farther de- 
fcription. The whole of the work is confined within a 
box fet on wheels, as is ufilial. It is all conftructed of 
wood, except the fpears of the pumps, and a few bolts. 
Engines on this plan-might be made in any place where 
•a common pump can; the inlide work will not be more 
than one quarter the ex pence of thofe on the ufual con- 
•ttrudtion ; and the labour of working them will be much 
lels than in the others: thefe conliderations certainly re¬ 
commend them to attention. 
A further contrivance for converting a common pump 
into a fire-engine, particularly on-board of (hips, has been 
recently invented by M. Robertfon Buchanan, of Roth- 
fay in Scotland, and for which he obtained the king’s 
letters patent, dated March 3 , 1796. We (hall give the 
particulars as fet forth by himfelf, viz. This pump, like 
the common pump, adts by the p re fibre of the atmo- 
iuhere ; but poflefles the following fuperior advantages : 
Firft, The water is difcbarged from this pump through 
two valves; tire one called the inner valve, fituated on 
the bore of the fudtion-piece, through which the water 
on raifing up the pifton firft partes, and thence is commu¬ 
nicated, by means of an aperture in the fide of the pipe, 
to the fecond or outer valve, which is placed at the bot¬ 
tom of the cittern, whence it pafies into the fpout. Se¬ 
condly, The outer valve is not only within the command 
ot a perfon’s hand, and may be at all times cleared, but 
is made fo as to afford a communication to clear the in¬ 
ner valve. Thirdly, thefe valves, not being confined to 
any particular dimenfions are made large enough to ad¬ 
mit any body or fubftance through them that is capable 
of palling through the fudtion-piece; and, being placed 
near to each other, and in an inclined pofition, gravel, 
dirt, or other things, cannot eafily lodge in the pump, 
and the water is thus refitted or wire-drawn as little as 
pottible in patting through the valves; and the pump is 
thus alfo made not liable to choke, or to have any un- 
necefiary wear of its parts; but the valves may alfo 
be placed horizontally, or in any other pofition, when 
circumftances require it. Fourthly, From the fize and 
fituation of the valves, they may be at all times eafily 
taken out, fo that they may without difficulty be readily 
repaired or renewed ; and hence this pump may be ef¬ 
fectually ufed as an engine for extinguifiiing fire. The 
following inftrudtions in regard to its conftrudtion, will 
more fully explain its nature and principle : 
This pump, in its body and parts, is made of wood, 
copper, caft-iron, or any other metal or material fuited 
to fuch purpofes, or partly of wood, and partly of me¬ 
tal ; but metal is particularly recommended for the parts 
above deck on-board (hips ; and it may be varied in form 
and dimenfions, as fituations and circumftances require. 
The valves beft fuited to the purpofes of this pump are 
of the kind called clack-valves. Their apertures are 
made of any form or ffiape, and of any dimenfions; but 
the elliptical form is the beft, becaufe it has been found 
that, where the apertures are of this fhape, the valves 
lofe lefs water at each (hutting than when they are of a 
circular form ; and the apertures ought to be made as 
large as the bore of the fudtion-piece, becaufe where the 
apertures of the valves are of the fame dimenfions with 
the bore of the fudtion-piece, the water will be thereby 
lefs refitted in parting through the valves. The valves 
may be made of any metal, but brafs is recommended as 
leatt liable to raft. A fiat piece of leather is fixed on 
the under part of the lid to render it elaftic. The lid of 
each of the valves turns upon two pivots, which have 
-freedom in their fockets to rife a little upwards, that 
any final 1 fubftance which happens to intervene near the 
hinge may not prevent the lid from lying clofe to the 
box. The bore of the fudtion-piece may be made of any 
fhape and dimenfions; but, for the reafon above-men¬ 
tioned, it is beft made of the fame fhape and dimenfions 
R E. 
with the aperture of the valves. For the purpofe of al¬ 
lowing a more eafy pafiage to the water, and for the bet¬ 
ter difeharge of oblong pieces of wood and other things 
which may be broug.htT.ip along with the water, the bore 
of the fudtion or lower pipe fnould, when the inner valve 
is inclined, receive a bended or curved form as it ap¬ 
proaches the inner valve, fo as to make its ultimate di¬ 
rection nearly at right angles to the inclined pofition of 
inner valve. From the lowed extremity to the fudtion 
or lower pipe, a reticulated grate, extending feme feet 
upwards on the outfide of the pipe, leaving a vacant 
fpace between the outfide of the pipe and the infide of 
the grate, may be fixed with advantage, in fituations 
where there is any danger that large quantities of dirr, 
chips, gravel, cr fuch like fttbftances, may lodge in the 
well, and choke the lower extremity of the pipe; for, 
where this grate is fo placed, although the lower extre¬ 
mity of it fhould be choked, the water will find a free 
pafiage through the openings of the grate above the dirt, 
gravel, or other fubftances, fo retained in the lower ex¬ 
tremity of the pipe. The inner valve is placed below 
the pifton ; that is, as near the lower extremity of its 
ftroke as the nature of the thing will admit, and is fixed 
by a rabbet, made in the periphery of the bore, or by any 
other means moll convenient ; and, when the pump is 
made of wood, it is introduced to its place by an aper¬ 
ture in the fide of the pipe, to allow the water a pafiage 
to the outer valve. The outer valve is, in this cafe, 
fixed in a frame of wood which covers this aperture, to 
which the outer valve is placed oppofite. The frame of 
wood containing the outer valve is inclofed by a ciftern, 
with or without a moveable lid, for the purpofe of keep¬ 
ing water above the outer valve when the pump is in 
adtion ; and the water is difeharged from the ciftern by a 
fpout, placed at a height fufficient to keep the outer 
valve covered with water when the pump is in adtion. 
A triangular piece of wood is fattened on each fide of 
the interior of the ciftern, to fecure or hold the frame 
of wood containing the outer valve; and the triangular 
pieces of wood are kept tight by interpofing tar, tallow, 
or any other fimilar fubftance. Thefe triangular pieces 
of wood are eafily removed as occafion may require ; and 
the frame of wood containing the outer valve may be 
taken off, when the inner valve is in need of repair, or 
when a more free accefs is wanted to it than the aper¬ 
ture of the outer valve admits of. The above is the 
mode of fixing the outer valve, when the pump is made 
of wood ; and, when made of wood, the working-barrel 
fhould be lined witb brafs to lefien the fridfion. But, 
when the pump is made of copper, caft-iron, or other 
metal, lining the working-barrel with brafs is unnecef- 
fary ; and the outer valve is fixed in the fide of the pipe, 
without being contained in a moveable frame of wood, 
and the triangular pieces of wood mentioned above are 
then unnecefiary ; but, in order to introduce the inner 
valve, and afterwards to get at it when in need of re¬ 
pair, the barrel is fattened immediately above the valves 
by means of a flanch. For the purpofe of letting fuch 
part of the air efcape (which is colledted in what is called 
fetching the water) as does not find its way through the 
outer valve, a fmall air-valve is placed, either in the pif¬ 
ton, or between the lower extremity of its ftroke and the 
inner valve ; but it is placed in the pifton with beft ef- 
fedt, for the purpofe of letting up a little water to aflift 
in keeping the pifton air-tight. This air-valve, however, 
is not abfolutely necefiary in either fituation; for, the 
pifton may be made fo pliant as to allow the remainder 
of the air fo colledted to efcape around its circumference; 
and, in all cafes where the water is to be raifed only to a 
fmall height, this air-valve is unnecefiary. Motion may 
be given to this machine by means of the common brake, 
or by what are commonly called bell-ropes, or by ropes 
led horizontally from a bended lever, or by any other 
method pradtifed in working the common pump, which 
it refembles. except in the particulars above-ftated. In 
order 
