756 MEC I-I A 
{bat of increafiag (he quantity of water which the ma¬ 
chine will raife, unlefs it were in a confiderable degree ; and 
indeed the very bed pumps will not raife a much greater 
proportion with the lame power. The only alteration 
which has been made in Mr. Cole’s pump, lince its firlt 
introduction near thirty years ago, is that they now omit 
the lower fprocket-wheel altogether, the afcendmg and 
defcending pipes being lo united by a curved metal tube, 
that the chain pad'es better than if a wheel was ufed. 
The cranks are made to takeoff, and apply when wanted, 
that they may not be in the way; they are long enough 
for thirty men to work at once. 
The hand-pumps for (hips, are thofe which aft with a 
barrel and bucket, worked by a lever or brake. Thofe in 
common ufe are fucking-pumps, made in the rudelt man¬ 
ner, with a wooden bucket and valves; but feveral im¬ 
proved con (tractions have been propofed, and are now 
adopted in the navy. Mr. Cole made great numbers of 
hand-pumps, which had brafs chambers, or barrels, fitted 
into the wood where the bucket worked. The valves 
were made of brafs, and fitted into a conical feat, and a 
door was provided in the lower part of the pump, to give 
accefs to the lower valve when requifite; it was clofed by 
a hoop furrounding the pump, and wedged tight. The 
brake, or lever of the pump, had a crofs handle at the 
end, of fufficient length to allow feveral men to work 
together; and on occafion other men could apply their 
(Length, by (landing on the deck below, and having a 
rope defcending through the upper deck from the end of 
the brake. 
Mr. Smeaton, in 1765, invented a hand-pump for fea- 
fervice, in which, befides the advantage that he expected 
to obtain from better niechanifm and proportion of the 
parts, he had the following objects in view. The com¬ 
mon (hip’s pump, in general, delivers its water upon the 
main deck, which, according to the (ize and conftruClion 
of the (hip, is four, five, or fix, feet above the furface of 
the fea, or load-water line, at the fame time that this line 
is not above from 14 to 18 feet above the (hip's bottom; 
it therefore appears that the ordinary pumps lift the wa¬ 
ter from one-third to one-fourth higher than the level at 
which the water might be delivered, and thereby require 
one-third or one-fourth more power to do the fame work, 
or with the fame power they dolefs work than they might 
do by one-third or one-fourth, in cafe the water was de¬ 
livered at or juft above the water-line. For this purpofe 
he ufed wooden trunks or pipes, proceeding horizontally 
from the uptight trunk of the pump, to carry off the 
water through the (hip’s iide, being fitted at the other 
ends into boxes, or fliort wooden tubes, let in through 
tlie (hip’s fide, and caulked juft above the load-water line. 
Thele fide-pipes were clolely jointed with the boxes in 
the (hip’s iide' at one end, and at the other end into 
(trong planks, which were bolted againft the (ides of the 
pump, in order that the (kite-pipes might be got our and 
in without diffurbing the pump, which was a fucking- 
pump, with its bucket worked by a lever or brake, upon 
the deck over the pump. From the top of the pump a 
{land-pipe was carried up to the main deck, or as high as 
was thought necefiary, to prevent the water reverting and 
running back into the (hip-over the top of the pump, when 
the fea rofe above the orifices of the fide-pipe, or when, 
from the (hip being in diltrefs, they were under her load- 
water line. By this, even when both boxes and pipes 
were wholly under water, it would no ways interrupt the 
action of the pump ; for, whenever the water in the (land- 
pipe rofe above the level of the water without, the preffure 
of tiie'column in the (land-pipe would caule it to make 
its way through tile fide-pipes, to that in this cafe no level 
was loff; and, though the pump was at red, no water 
could revert down the pump, becaufe there were the 
vaives'of both bucket and fixed box or clack which pre¬ 
vented it. Tiie working- baprel was of brafs, and very 
.truly bored, the bucket and fixed box being of the fame 
N I C g; • 
conffruflion as thofe ufed in fteam-engines; and the pump- 
rod was made of greater bulk than was neceflary, not 
merely for flrength, but by way of weight, that, when the 
brake was lifted up, the pump-rod (hould readily defeend 
by its own weight. The brake of the pump had a branch 
fixed on rather obliquely at each fide, fo as to form three 
handles, for four men to work at once; they flood one on 
each Iide the middle (tern of the brake, and one on the 
outfide of each of the branches; and every quarter of an 
hour they could relieve themfelves by changing hands, 
which was done by changing places. They were intended 
to make no more than 25 llrokes in a minute, moving the 
pump-rod 17J inches, up and down, at each ftroke, the 
barrel being a nine-inch bore; this was much better than 
making (hotter ftrOkes and quicker, as .they ufually do. 
Their hands moved up and down about four feet fix 
inches; and, by working with tiiis (troke at a moderate 
rate, fo as to hold it an hour, four men would in that 
time deliver 20 tons at the height of 22 feet. This was 
upon a fuppofition of railing the water fo the ufual height 5 
but, when, by the application of tire maxim before de- 
ferihed/this perpendicular was (hortened to 16 or 17 feet, 
then nearly the fame delivery could be made by three 
men, or proportionably more by four men, that is, as 
17 : 22 :: 20 : 26 tons at 17 feet. The foot of the pump 
was let through the (hip’s inner planking or ceiling, be¬ 
twixt two of the floor-timbers, and did not touch the 
bottom or. outfide planking within z\ inches, the lower 
end being rounded within-fide like a trumpet-mouth, it 
being a bad plan to have the pump (landing upon its 
lower extremity, with holes bored to let in the water, as 
it is thus very liable to be cboaked by dirt. A plank of 
the ceiling was made to lift up near the pump’s foot, that 
a man could occalionally get in his arm, to clear away any 
chips, fand, dirt, or other matter, that (hould happen to 
be drawn thither. 
Mr. Noble has furniffied a great number of hand-pumps 
for the navy. His invention is reprefented at fig. 84. It 
confifts of a working-barrel AB, with two piftons C and 
B, which are moved up and down alternately by the rods 
fixed to the lever EMN. The rod of the pifton B pafies 
through the pifton C, and the pilton C moves upon the 
rod AB. When the piilon-rod B is deprefled and ele¬ 
vated, it will make the water rife in the barrel A, in the 
fame way as in the fucking pump, whether the valve C 
be moveable or not. Let us now luppofe that the water 
is raifed to A. Then, if the pillon B is elevated by de¬ 
prefling the extremity N of the lever, the water at A will 
be raifed higher in the barrel, and ifl'ue at the (pout P; 
and, when the fame pilton B is deprefled by elevating the 
end N of the lever, the pifton C is evidently raifed, and 
the water above it will be expelled at P. This pump, 
therefore, will give a continued Itream; for, as the piftons 
afeend and defeend alternately, one of them.muff always 
be forcing the water out at P. The piftons are elevated 
and deprefled by means of toothed arches, c and d, work¬ 
ing 5 'n the teeth of a rack, at the extremities a , b, of the 
pilton-rod. A pump of this kind will require no lower 
valve, unlefs by way of precaution, in cafe either bucket 
(hould fail ; and then it would become a Angle pump. 
The idea is ingenious; but the complication of the ftuf- 
fingfbox in the upper bucket prevents their being readily 
taken out, if the pump choaks up, as all (hips’ pumps are 
liable to do from chips or loofe ballad; and hence it has 
never been in favour with the feamen, although it acts 
very well when in order. 
The pump invented by Mr. Buchanan is fliown at 
fig. 85. In the vertical feifion DGA, A is the fuflion- 
barrel, D the workingTarrel, E the pifton, G the (pout, 
B the inner valve, and C the outer valve. Thefie valves 
are of the kind called clack values , and have their hinges 
generally of metal. It is eafily (ten that, when the pifton 
E is railed, the water will rile through the fuflion-barr.el 
A, into the working-barrel D, in the lame way as in the 
fucking- 
