===================+========================+===============
SIZE OF ENGINES. | CAPACITY. | WEIGHT.
-------------------+------------------------+---------------
Double Extra First | 1,300 gallons per min. | 10,800 pounds.
Extra First | 1,100 gallons per min. | 9,800 pounds.
First | 900 gallons per min. | 8,800 pounds.
Second | 700 gallons per min. | 7,800 pounds.
Third | 600 gallons per min. | 6,800 pounds.
Fourth | 500 gallons per min. | 5,800 pounds.
Fifth | 400 gallons per min. | 4,800 pounds.
-------------------+------------------------+---------------
The foregoing list of the sizes, capacities, etc., of the fire
apparatus now in general use, affords a very good comparison between it
and that which has, little by little, progressed for two thousand years
to its present high plane. _The application of electric power to the
operation of the pumps_ and the propulsion of the apparatus is yet in
too elementary a stage for present discussion in a work of this scope
for—
It is essential that the machinery relied upon for fire protection
should at all times be ready for instantaneous and effective service;
this, because both life and vast property interests are at stake,
_hence of all machines made, the modern steam fire engine is produced
with a niceness of finish and accuracy of fit equaled by no other_,
when size is considered; it approaches towards the perfection seen in
the mechanism of a fine watch.
[Illustration: FIGS. 390, 391.]
This degree of excellence has been arrived at by successive steps. The
illustration on page 92, Fig. 388 exhibits the fire-fighting tools of
the early Romans and similar apparatus was used in England as late as
the fifteenth century. The implements shown are a syringe, a sledge
hammer, two fire hooks and three leathern buckets conveniently arranged
against a wall. _The owners of houses or chimneys that took fire were
fined_; and men were appointed to watch for fires and give the alarm.
In 1472 a night bellman was employed in Exeter to alarm the inhabitants
in case of fire, and in 1558, leathern buckets, ladders and crooks,
were ordered to be provided for the same city; no application of the
pump seems to have been then thought of.
Syringes continued to be used in London till the latter part of the
17th century, when they were superseded by more improved machines.
They were usually made of brass and held from two to four quarts. The
smaller ones were about two feet and a half long, and an inch and a
half in diameter; the bore of the nozzles being half an inch. _Three
men_ were required to work each, which they achieved in this manner:
one man on each side, grasped the cylinder with one hand and the nozzle
with the other; while the third man worked the piston! Those who held
the instrument plunged the nozzle into a vessel of water, the operator
then drew back the piston and thus charged the cylinder, and when it
was raised by the bearers into the required position, he pushed in the
piston and forced, or rather endeavored to force, the contents upon the
fire.[A]
[A] NOTE.—We are told that some of these syringes are preserved in one
or two of the parish churches. It can excite no surprise that London
should have been almost wholly destroyed in the great fire of 1666,
when such were the machines upon which the inhabitants chiefly depended
for protecting their property and dwellings. If the diminutive size of
these instruments be considered, the number of hands required to work
each, beside others to carry water and vessels for them, the difficulty
and often impossibility of approaching sufficiently near so as to
reach the flames with the jet, the loss of part of the stream at the
beginning and end of each stroke of the piston, and the trifling effect
produced—the whole act of using them, appears rather as a farce. These
primitive devices were known as “hand squirts.”
[Illustration: FIG. 392.]
Figs. 390 and 391 show an early form of syringe. A description of it
translated from the original Greek, written by Hero of the ancient city
of Alexandria, reads thus—“A hollow tube of some length is made, A,
B; into this another tube, C, D, is nicely fitted, to the extremity
of which is fastened a small plate or piston; at, D, is a handle, E,
F. Cover the orifice, A, of the tube, A, B, with a plate in which an
extremely fine tube, G, H, is fixed, its bore communicating with A, B,
through the plate—as a vacuum is thus produced in A, B, something else
must enter to fill it, and as there is no other passage but through the
mouth of the small tube we shall of necessity draw up through this any
fluid that may be near.”
Fig. 392 is a copy of an old engraving (A.D. 1568) which shows an
“engine” of this type sufficiently enlarged to contain a barrel or more
of water and as a matter of necessity, placed on a carriage.
[Illustration: FIG. 393.]
To eject the water uniformly, the inventor moved the piston by a screw;
and when the cylinder was emptied, it was refilled through the funnel
by an attendant, as the piston was drawn back by reversing the motion
of the crank. When recharged, the stop cock in the pipe of the funnel
was closed and the liquid forced out as before. As flexible pipes of
leather, the “ball and socket” and “goose-neck” joints had not been
introduced, some mode of _changing the direction of the jet_ of this
enormous syringe was necessary. To effect this, it is represented
as suspended on pivots, fastened in two upright posts: to these are
secured (see figure) two semi-circular straps of iron, whose centers
coincide with the axis, or pivots, on which the syringe is balanced. A
number of holes are made in each, and are so arranged as to be opposite
each other. A bolt is passed through two of these, and also through a
similar hole, in a piece of metal, that is firmly secured to the upper
part of the open end of the cylinder; and thus holds the latter in any
required position. The iron frame to which the box or female part of
the screw is attached, is made fast to the cylinder; and it is through
a projecting piece on the end of this frame that the bolt is passed.
By these means, any elevation could be given to the nozzle, and the
syringe could be secured by passing the bolt through the piece just
mentioned, and through the corresponding holes in the straps. When a
_lateral_ change in the jet was required, the whole machine was moved
by a man at the end of the pole, as in the figure. Jointed feet were
attached to the frame which were let down when the engine was at work.
Fig. 393 shows an engine for extinguishing fires, which has come down
to us from the times of Hero, who thus describes it:
NOTE.—The siphons used in conflagrations are made as follows. Take
two vessels of bronze, A B C D, E F G H (Fig. 393), having the
inner surface bored in a lathe to fit a piston (like the barrels of
water-organs), K L, M N, being the pistons fitted to the boxes. Let
the cylinders communicate with each other by means of the tube, X O
D F, and be provided with valves, P, R, such as have been explained
above, within the tube, X O D F, and opening outwards from the
cylinders. In the bases of the cylinders pierce circular apertures,
S, T, covered with polished hemispherical cups, V Q, W Y, through
which insert spindles soldered to, or in some way connected with,
the bases of the cylinders, and provided with shoulders at the
extremities that the cups may not be forced off the spindles. To the
center of the pistons fasten the vertical rods, S E, S E, and attach
to these the beam A´ A´, working, at its center, about the stationary
pin, D, and about the pins, B, C, at the rods, S E, S E. Let the
vertical tube, S´ E´, communicate with the tube, X O D F, branching
into two arms at, S´, and provided with small pipes through which to
force up water, such as were explained above in the description of
the machine for producing a water-jet by means of the compressed air.
Now, if the cylinders, provided with these additions be plunged into
a vessel containing water, I J U Z, and the beam, A´ A´, be made
to work at its extremities, A´, A´, which move alternately about
the pin, D, the pistons, as they descend, will drive out the water
through the tube, E´ S, and the revolving mouth, M´. For when the
piston, M N, ascends it opens the aperture, T, as the cup, W Y,
rises, and shuts the valve, R; but when it descends it shuts, T, and
opens, R, through which the water is driven and forced upwards. The
action of the other piston, K L, is the same. Now the small pipe, M´,
which waves backward and forward, ejects the water to the required
height but not in the required direction, unless the whole machine be
turned round; which on urgent occasions is a tedious and difficult
process. In order therefore, that the water may be ejected to the
spot required, let the tube, E´ S´, consist of two tubes, fitting
closely together lengthwise, of which one must be attached to the
tube, X O D F, and the other to the part from which the arms branch
off at, S´; and thus, if the upper tube be turned round, by the
inclination of the mouthpiece, M´, the stream of water can be forced
to any spot we please. The upper joint of the double tube must be
secured to the lower to prevent its being forced from the machine by
the violence of the water. This may be effected by holdfasts in the
shape of the letter L, soldered to the upper tube, and sliding on a
ring which encircles the lower.
[Illustration: