EXPLANATION OF THE PLATES.
373
every two or three hours, which cold
water, having to be brought up to the
boiling point, causes a considerable waste
of fuel to take place.
4. In injection engines, the boilers will,
after every precaution is taken, become
coated with hard scale of considerable
thickness ; this being a bad conductor of
heat prevents the free transmission thereof
from the fires to the water, causes the
boilers to burn and wear out very
rapidly, and greatly increases the con
sumption of fuel.
5. In order to prevent the boilers of
injection engines from burning and wear
ing out with a rapidity that could not be
submitted to, it is necessary in long
voyages to suspend the working of the
boilers in order to empty and cool them,
for the purpose of clearing away and
chipping off the scale that firmly adheres
to them, which operation considerably
injures the boilers.
6. In injection engines, the oil which
is put into the cylinders, stuffing-boxes,
slides, &cc., is speedily carried away by
the injection water into the sea; the time,
therefore, of its being in the engines is so
short that nine tenths of it is wasted and
does but little if any good, and it does not,
as in the patent engines, enter the boilers
and protect them from the corrosive ac
tion of hot salt water.
7. In injection engines, a portion of the
salt contained in the water is carried over
mechanically along with the steam into
the working cylinders, slowly corroding
and wearing the slides, valves, and other
The patent boilers of the engines will
be perfectly clean not only for many
voyages but for years, and their dura
bility will be very much greater than
that of boilers supplied with salt water,
and a comparatively small consumption
of fuel will also be the result.
In the patent engines, all delays and
inconveniences arising from the empty
ing and clearing of boilers are entirely
superseded, for by their permanent clean
ness, the water they contain entirely de
fends them from the action of the fire,
and as no deposit takes place, they are
not subjected to the injury caused by
chipping off scale, as in injection engines.
In the patent engines, not a particle of
the oil which is given to the internal parts
of the engine, &c., is washed away into
the sea or lost, but it is all carried into the
boilers, whereby they are protected from
corrosion, and an ample lubrication of the
engines is effected at scarcely any cost, as
hereafter mentioned.
In the patent engines, a portion of oil
being always, as before stated, introduced
in commixture with the pure water into
the boilers, it passes over mechanically
along with the steam in minute parti-