with a well-regulated cut-off, for practical men know now that the
essential points of excellence in the steam engine are a good boiler, which
generates the greatest quantity of steam for the least consumption of fuel;
and, secondly, a reliable cut-off, which uses the steam to the best
advantage, by admitting the proper quantity for the work required.

STEAM FIRE ENGINES.--Portable engines for the extinguishment of fires, are
an American invention, and to Messrs. A.B. & E. Latta, of Cincinnati,
working on the right principles, is due the credit which they claim in
their circular, as follows:

"We claim to be the _original_ and first _projectors_ of the _first
successful steam fire engine_ in the world's history. There have been many
attempts at making a machine of such construction as would answer to
extinguish fires; but none of them proved to be available in a sufficiently
short space of time to warrant their use as a fire apparatus. We hold that
a steam fire engine should be of such nature as to be brought into
requisition in as short a space of time as is necessary to get the machine
on the ground, and the hose laid and ready to work: that is, supposing the
fire to be within one square of the place where the steamer is located. The
object in locating a machine at any point is to protect that immediate
vicinity; and it is therefore absolutely necessary to have it available in
the shortest space of time, and that with unerring certainty. We think that
reliability is of the greatest importance to the protection of a city from
fire, as everything is dependent on the _working_ of such apparatus in
time; and for this reason no expense should be spared on this kind of
machinery."

Fig. 73 is a representation of one of the Messrs. Latta's fire engines, of
which there are many of different classes, according to the requirements;
they say that they can furnish engines as low as $1,000, and have made some
for $10,000.

The first peculiar feature of this engine is the boiler; it differs
entirely from all boilers now in use.

[Illustration: Fig. 73.]

The fire box or furnace is simply a square box or furnace of any required
dimensions; it is nothing more than a water space surrounding the fire,
stay-bolted as all water spaces are. It is made of boiler plate in the
usual manner. The water space extends only 2/3 of the height, the balance
being a single sheet. The bottom of this fire box is crossed by grate bars
to support