022 
Height of 
Of the air 
Proportion of 
Height 
water in 
compress - 
air .r clasti- 
of the 
air-bar. 
cd. 
city. 
spout. 
h 
* 
2 
33 
§• 
* 
3 
66 
i 
■f 
4 
99 
A 
T 
* * 
5 
132 
, f 
i 
6 
105 
■■ T 
7 
7 
193 
* • 
* 
8 
231 
* 
* 
9 
264 
t’o 
T*d 
10 
297 
n — 1 
n 
1 
n 
n (n — 
1) 33 
Various alterations and improvements have 
been made from time to time in the con- 
struction of fire-engines. The contrivers of 
-some of thesii improvements, as Messrs. Bra- 
mah, Dickenson, Simpkin, R own tree, and 
Philips, have secured their inventions from 
infringement by patents, the specifications 
ctf most of which may be seen in the Reper- 
tory of Arts and Manufactures. In the year 
1785, the silver medal and 20 guineas were 
conferred by the Society for the Encourage- 
ment of Arts, Ac. on Mr. Thirst, as a reward 
tor his contrivance to increase the effect of 
engines in extinguishing fires ; of which the 
following is a short description: From a 
platform rises an upright pole or mast, of such 
height as may be judged necessary ; a gaft 
slides upon it in an ascending direction, and 
along both is conveyed the leather hose from 
the engine. The branch or nose-pipe of the 
engine projects at the extremity of the gaft; 
towards which an iron frame is lixed, whence 
two chains are suspended ; and from these 
hang ropes, which serve to give an horizontal 
direction to the branch; while other ropes 
that run through proper pulleys, and are thus 
conveyed down the mast, serve likewise to 
communicate a vertical motion to it. Bv 
these means the branch or nose-pipe of the 
engine is conducted into the window of any 
room where the fire more immediately rages’; 
and the effect of the water discharged is ap- 
plied in the most efficacious riTanner to the 
extinguishing of the flames. 
A very cheap and simple fire-engine is that 
invented in America by Mr. Benjamin Dear- 
born, who communicated it to the American 
academy of arts and sciences, from whose 
Memoirs for 1794 we extract the following 
particulars : 
Fig. 2. AB and CD are the edges of two 
planks, confined by four bolts; ah and cd 
are two cylindrical barrels, in each of which 
a piston, with a valve, is fastened to the spear 
e, and is moved up and down alternately by 
the motion of the arms EE. Beneath each 
barrel a hole is made through the plank AB, 
which is covered with a valve. The arms 
EE are suspended on the common centre/: 
there are also arms parallel to these on the 
opposite^ side: gg are the ends of handles 
which are fastened across the ends of the 
arms. At It a bolt goes across from arm to 
arm, to which the piece ik is affixed, and on 
which it plays ; the lower end of this piece is 
fastened to the spear e. G lj is a standard 
for the purpose of supporting the arms, to 
which there is a correspondent one on the 
opposite side: both are notched into the 
edges of the planks, where they are secured 
by a bolt, which passes through them at /, 
, ENGINES. 
and has a nut or fore-lock on the opposite 
side. HI, HI, are square braces, answering 
the purpose of ducts, through which the wa- 
ter ascends from the barrels, passing through 
the plank at m. KL, KL, are irons in the 
form of a staple, in order to confine the 
braces : the lower ends of these irons meet, 
and are secured by a bolt passing through 
them, and MN uv, which is a piece that goes 
up through a mortice in the centre of the 
planks. Tins piece is square from the lower 
end till it reaches the top of the braces; 
whence they become cylindrical to the top, 
the upper end being perforated sufficiently 
low down in order to communicate with the 
braces. OP is an iron ring that surrounds 
the tube, and lias two shanks which ascend 
through the head, which screws on the top at 
PQ- 
Fig. 3. is the same engine; the arms and 
standards being taken off, in order to deli- 
neate more clearly the mode of securing the 
braces ; an object which is completely ef- 
fected by a wedge driven into the mortice a : 
beneath the upper plank b is a hole for ad- 
mitting a passage to the bolt, which secures 
the standards. In this figure a side view of 
the head is given, with the pipe in a perpen- 
dicular direction. 
'File machine is confined within a box, set 
on wheels, as in the common fire-engines. 
The whole is made of wood, excepting the 
spears of the pumps, and a few bolts, &c. 
The advantages of this machine are, that it 
can be made in any place where common 
pumps are manufactured; the interior work 
will not exceed one-fourth of the price of 
those which are constructed on the usual 
plan; and they are incomparably more 
easy to work than the common ones: cir- 
cumstances which strongly recommend the 
American fire-engine to the attention of the 
public. 
Since the construction of engines for the 
extinguishing of tires has long been consider- 
ed of very great importance, it is no wonder 
that many persons have devoted much of 
their time and talents to this subject. 
Engine, pile, a machine by which piles 
are driven into the earth for the foundations 
of piers and other structures. 
In pile-engines the contrivance consists in 
drawing up a great weight, called a ram or 
hammer, to a moderate height, and then let- 
ting it fall freely with a considerable momen- 
tum upon the head of the pile. In the most 
simple pile-engines the ram is drawn up by 
men pulling at a cord running over a fixed 
pulley, and suffering the cord to slip from 
their hands when the weight is sufficiently 
elevated. Among the more complex engines, 
the best are those invented by Mr. Vauloue 
and by Mr. S. Bunce. 
Description of Vauloue' s pile-engine. (See 
Plate Engines, fig. 4.) — A is a great upright 
shaft or axle, on which are the great wheel 
B and the drum C, turned by horses joined 
to the bars S,S. The wheel B turns the 
trundle X, on the top of whose axis is the 
fly O, which serves to regulate the motion, as 
well as to act against the horses, and to keep 
them from falling when the heavy ram Q is 
discharged to drive the pile P down into the 
mud in the bottom of the river. The drum 
C is loose upon the shaft A, but is locked 
to the wheel B by the bolt Y. On this drum 
the great rope HH is wound ; one end of 
the rope being fixed to the drum, and the 
other to the follower G, to which it is convey- 
ed by the pulleys I and K. In the follower 
G are contained the tongs F, that take hold of 
the ram Q by the staple R for drawing it up. 
D is a spiral or fusee fixed to the drum, on 
which is wound the small rope T that goes 
over the pulley U, under the pulley V, and 
is fastened to the top of the frame at 7. To the 
pulley-block V is hung the counterpoise W, 
which hinders the follower G from accele- 
rating as it goes down to take hold of the ram ; 
for, as the follower tends to acquire velocity 
in its descent, the line T winds downwards 
upon the fusee in a larger and larger radius, 
by which means the counterpoise W act- 
stronger and stronger against it; and so al- 
lows it to come down with only a moderate 
and uniform velocity. The bolt Y locks the 
drum to the great wheel, being pushed up- 
ward by the small lever3, which goes through 
a mortice in the shaft A, turns upon a pin in 
the bar 3, fixed to the great wheel B, and 
has a weight 4, which always tends to push 
up the holt Y through the wheel into the 
drum. L is the great lever turning on the 
axis m, and resting upon the forcing-bar 5,5, 
which goes through a hollow in the shaft A, 
and bears up the little lever 2. 
By the horses going round, the great rope 
H is wound about the drum C, and the ram 
Q is drawn up by the tongs F in the follower 
G, until the tongs come between the inclined 
planes E ; which, by shutting the tongs at the 
top, opens them at the foot, and discharges 
the ram, which tails down between the guides 
bb upon the pile P, and drives it by a few 
strokes as far into the mud as it will go ; aft t r 
which the top part is sawed off close to the 
mud by an engine for that purpose. Imme- 
diately after the ram is discharged, the piece 
6 upon the follower G takes hold of the ropes 
ua, which raise the end of the lever L, and 
cause its end N to descend and press down 
the forcing-bar 5 upon the little lever 2, 
which, by pulling down the bolt Y, unlocks 
the drum C from the great wheel B; and 
then the follower, being at liberty, comes 
down by its own weight to the ram ; and the 
lower ends of the tongs slip over the staple 
R, and the weight of their heads causes them 
to fall outward and shut upon it. Then the 
weight 4 pushes up the bolt Y into the drum, 
which locks it to the great wheel, and so the 
ram is drawn up as before. 
As the follower comes down, it causes the 
drum to turn backward, and unwinds the 
rope from it, whilst the horses, great wheel, 
trundle, and fly, go on with an uninterrupted 
motion; and as the drum is turning back- 
ward, the counterpoise W is drawn up, and 
its rope T wound upon the spiral fusee D. 
There are several holes in the under side 
of the drum, and the bolt Y always takes the 
first of them that it finds, when the drum 
stops by the falling of the follower upon the 
ram, until which stoppage the bolt has npt 
time to slip into any of the holes. 
The peculiar advantages of this engine are, 
the weight, called the ram or hammer, may 
be raised with the least force; that when jt 
is raised to a proper height, it readily disen- 
gages itself and falls with the utmost free- 
dom ; that the forceps or tongs are lowered 
down speedily, and. instantly of themselves 
again lay hold' of the ram and' lift it up. 
