MECH 
pumps are brought into one by bolting them together at 
the top, and are fufpended from the beam or lever, as be¬ 
fore mentioned. They are made of wood, the lengths 
being united together by iron joints; but even thele in 
deep mines are of fuch great weight as to require a fecond 
beam or lever, placed on the oppofite fide of the pit to 
the engine, and having a balance-weight at the outer end ; 
becaufe it would be too great a weight for any beam to 
bear, if a fufficient balance were put upon the oppofite end 
of the fame working-beam that bears the (train of working 
the pumps ; if they are of light wood, a confiderable por¬ 
tion of their weight is taken oil by their being immerfed 
in the water which the pumps contain. 
A plan which is common in the mines of Cornwall, 
obviates the necedity of thus balancing the pump-rods ; 
it is by employing forcing-pumps inftead of lift or fuc- 
tion pumps. In thefe the engine is employed to lift the 
weight of the rods ; and their defcent is the power that 
raifes the. water in the pump, by prelung down the piiton 
or forcer, and expelling the water from the barrel at the 
bortom through a valve into a pipe which afcends the pit. 
The conflruftion of the pump is varied from that in com¬ 
mon ufe, though its principle is the fame. Inftead of the 
barrel being bored correftly withinfide, and fitted with the 
leathered forcer, the forcer is made rather longer than the 
(broke of the pump ; and, being made true and fmooth on 
the outiide, is fitted in a collar of leather at the top of 
the barrel of the pump. By this means, when the piiton 
is moved up and down, it increafes and diminifhes the ca¬ 
pacity of the barrel, which being provided w ith valves at 
the bottom and at the foot of the pipe, it will raife or force 
up the water in the fame manner as the force-pump before 
defcribed. 
The fmSlion-pumps before-mentioned ufed in mining, 
are always made of caft-iron, in lengths of fix or eight 
feet, (crewed together at the flanches, forming a long tube, 
■which is called the pile or pillar of pumps. The working- 
barrel of each lift of pumps, or that length of pipe in 
which the bucket moves, is ufually fourteen to twenty 
feet above the bottom ; and has at its upper end a wider 
part, and a cover, which, like that above mentioned, 
takes off by (crews, to new-leather or to repair the buc¬ 
ket. The bottom length of mine-pumps is called the 
wind-bore, ufually enlarged at two or three feet from the 
bottom, and diminilhing thence to a point like that of an 
egg, which part is full of rows of holes three quarters or 
an inch in diameter. The upper row of thefe holes is 
plugged up with deal plugs, which the miners can open 
or ltop as the water increafes or otherwife, and according 
to the going of the engine. When a pit or mine is firlt 
linking, it becomes neceflary to contrive the means of 
drawing the water completely from the bottom, that the 
men may not have to (tand in the water to work, which, 
befides its inconvenience, prevents them ufing gunpowder, 
if the bottom is rocky. Sometimes, inftead of the plugs 
of wood, the holes of the wind-bore are furrounded by a 
circular apron of Wrong leather, made fall and tight above 
to the pipe; which apron the miners can from time to 
time turn up or down like the cufF of a coat, fo as to re¬ 
gulate the accefs of water, and prevent, as much as polfi- 
ble, the drawing of air by the pumps, as this deranges the 
motion of the engine. In finking pits, the lower lift of 
pumps (liould (land in the deepelt hole which has been 
made in the bottom of the pit, and for this purpofe, when 
a new hole has been made, either by picking or Waiting, 
near to the pumps, they are levered towards, and let to 
(ink into, fuch new hole. In long lifts and heavy pumps, 
this lowed and moveable length of tlie pump is wholly or 
in part fufpended by Wrong ropes attached to the great 
wimllafs, which is, in all fuch cafes, provided near the 
(haft for drawing the pump-rods, or the pumps themfelves, 
in cafes of need. As the (haft is deepened, new lengths 
of pump-barrels are added at the top of the lower lift, 
generally about a yard at a time, and the pump-rods are 
lengthened as the pump requires. This, which is the 
Vul. XIV. No. 1010. 
ANICS. 753 
common mode of working in finking pits, has many in¬ 
conveniences : i. As it is neceflary for the pumps, whilH 
finking, to keep the water very low in the pit, the engine 
frequently goes too fait, in confequence of the pump draw¬ 
ing up air, and carries up by the violence of the current 
fmall pieces of (tone, coal, or other fubllances, and lodges 
them above the bucket upon the valves; which nmft con- 
fiderably retard the working of the pump, and wear the 
leather, z. When the engine is fet to work, (after hav¬ 
ing been (topped whilft working upon air, and confe- 
quently a quantity of air remaining in the pump-barrel, 
with the fmall (tones, &c. depofited on the valves of the 
bucket,) it often happens that the compreflure of the air 
by the defcent of the bucket, is not fufficient to over¬ 
come the weight of the bucket-valves fo loaded with rnb- 
bifh, and the column of water in the Wand-pipes: the 
pump is hereby prevented from catching its water. The 
ufual remedy for this is to draw the bucket out of the 
working-barrel, until a quantity of water has efcaped by 
its fides to difplace the air: this evil often arifes from the 
unneceflary magnitude of the fpace between the bucket 
and clack. 3. The pumps being fufpended in the pit by 
capftan-ropes for the purpofe of being readily lowered as 
the pit is funk, the firetching of the ropes (efpecially when 
finking in foft IIratn) occafions much trouble, by fufler- 
ing the pumps to reft on the bottom, and choke. But the 
molt (erious evil is, that the miners, in (hifting the pump 
from one place to another, that they may dig in all parts 
of the pit, throw them very far out of the perpendicular, 
thereby caufing itnmenfe friction and wearing in all parts, 
befules endangering the whole apparatus, by breaking the 
bolts and (lays, and (training the joints of the pipes. 
Mr. William Brunton, of Butterly iron-works in Der- 
byfliire, has prefented to the Society of Arts, an improved 
pump for mining, which obviates all the above difficulties. 
To avoid the pump drawing air, he has introduced a fide- 
pipe, connecting the parts of the working-barrel which 
are above and below the bucket, which pipe lias a (top- 
valve, that the miner can regulate with the greatelt eafe, 
fo as to keep the engine to its full (troke, without draw¬ 
ing air, by letting down the water from the upper part of 
the barrel into the lower, fo that it is working again in 
its own water. Inftead of having the whole weight of the 
lower lift of pumps Handing on the bottom, it is fixed in 
the pit by crofs-beams, and the miner lias only to lift and 
move an additional pipe or wind-bore, which Hides upon 
the lower length of the pump like a telefcope, to lengthen^ 
down ; and this additional wind-bore is befides crooked, 
and turned afide like a fiiort crank, which, by the facility 
with which it turns round in the leathered collar above the 
nofe of it, can ealily be removed into every frefli hole 
which is made in the bottom by the miners. The pumps 1 
are fupported in the pit by beams placed acrofs at proper 
diltances, fo as to fuit the lengths of the pipes, or lengths 
of the pump, which are nine feet. Short pieces are laid 
acrofs thefe, with half-circular holes in them, which, being 
put round the pump, juH beneath the Handies, firmly fuf- 
tain its weight, but may quickly be removed when it is 
required to lower the pumps in the pit; and, as they are 
not fafiened by any bolt, they do not prevent the pumps 
being drawn upwards, if it becomes neceflary to take them 
out when the pit is full of water. The pumps by thefe 
means remain Hationary, and the fuftion-pipe lengthens 
as the pit is funk, until it is drawn out to its full extent; 
the whole column is then lowered to the next flanches, 
and another pipe is added to the top. The pumps beins- 
thus kept Hationary till nine feet are funk, the pipe at the 
top will of courfe deliver the water at tiie fame level at 
all times; and, inllead of being obliged to lengthen the 
column every yard funk, it will only be neceflary every 
nine feet. 
Fig. 78 explains the conflruftion of Mr. Brunton’s 
pump, being a fiction through the centre of the workim.. 
barrel and luction-piece. A is the door which unferews 
to get at the clack of the pump ; B is the working-barrel, 
9 F with 
