The national era. [volume] (Washington [D.C.]) 1847-1860, 1853-01-27
THE NATIONAL ERA WASHINGTON D. c. JANUARY 81, 1858

pands the air in the working cylinder is saved,
and made to do duty over and over again This
it is that produces the astonishing economy of
fuel, which is one of the great Characteristics
of the invention. In a steam engine the heat
is used but once ; it passes away, and therefore
has to be perpetually renewed In the caloric
engine it is economical This is an immense
advantage.
The apparatus is formed of iron wire lie of
an inch in diameter, woven into web dense
enough for the holes or meshes to occupy half
the surface. Fifty thieknesses, or disks, of this
wire cloth aSe used in each pipe connecting the
reservoir and working cylinders. Each disk is
feet long and wide, and contains half
million of meshes. They are placed close to-
gether in the pipe between the working cyliu-
der and the two valves, which let in the new
air and let ont that which has been used. Thus
all the air which comes in passes through the
meshes Of the wires, as does all that goes out.
Here lies the wonder of the invention. The
heated air in going out leaves its heat in these
wires, and the cold air in coming in takes it
up again. la the engines of the Ericsson the
air which comes out is but 80 degrees hotter
than the atmosphere, though before passing
through the wires it was 3S4 degrees hotter
Even these 80 degrees might be saved, says
Captain Ericsson, by increasing the number of
wire disks, but it is practically unnecessary.
This apparatus is called the regeneration.
Though the principle of it is essentially the
same as that of Davy's Safety Lamp the glory
of its application to mechanical purposes is
Captain Ercisson's forever.
As We said, there are four of these double
cylinders, four working and four supply Ac-
cordingly there are four furnaces, ingeniously
arranged. and set without any extraordinary
outlay of brick such MS has been reported In
these small fire is kept up with anthracite
coal, which is preferable to other fuel, because
it does not blaze-only its radiatng heat is en-
ployed, From the crate to the apex of the
cylinder bottom, which is arched, of course,
there is distance of five feet The cylinder
bottom is " J. inches thick. Before the engine
is put in motion it may get to a brown heat, but
at that distance 1t cannot get hotter. As soon
as the cold air is let in, it cools much below that
point Thus there is no danger either of flu
sion, cracking, or oxydizing of the cylinder
bottom, all of which have been predicted by
the skeptical. A cylinder-bottom will last five
years-as long as steam boiler; or, if it gives
out, can easily be replaced. The difference in
the cost of replacing cylnder-bottoms and
steam boilers would, in large ship, be from
thirty to forty thousand dollars in favor of the
former
The piston in the working cylinder is made
s feet deep from top to bottom, concave under
meath to fit the cylinder bottom, and fiat at the
top The top, as well as the sides, are of iron,
but the space between is filled with gypsum
and charcoal non-conductors Of heat Thus.
while the bottom has the temperature of the
hot air in the cylinder the top is perfectly ooor
The heat there is barely sufficient to keep the
tallow used for fabrication in a fluid state, not
to burn it. In fact, one can stand upon it as it
plays up and down, and many gentlemen amused
themselves yesterday by riding there This
enables the engineer at any time to grease
ust the part of it which he may desire; when
the ship is careening for instance, and the fric,
ton of the piston is all on one side that side
can be directly fabricated. This is point of
great practical Importance which cannot be
attained in a steam engine. Nor is there any
danger of burning the packing, for it is at the
top of the piston and never comes within less
than feet of the fire.
The cylinders act in pairs, and in each pair
the action is reciprocrating that is to say, as
the piston goes up in one it goes down in the
other.
The pressure for which the caloric engine is
calculated is 10 lbs. per square inch, and TO
obtain this, it is necessary to heat the air to
3S4 deg. By raising the air to $50 deg,
a pressure of Is lbs. could be obtained, but IL
is sufficient for. practical purposes, and more
convenient to manage. Capt. Ericsson is of
opinion that that will be retained as the max
imum pressure by future builders of engines
Yesterday, owing to the unfinished state of the
machine, and especially of the valves, it was
impossible to get more than lbs. pressure
With that, nine OF ten revolutions were obtain
ed per minute The full number of revolutions
to be had from the Ericsson's engines is reck-
oned at 10 and at that rate it is calculated that
she will make from 10 to I2 miles On hour.
This is the utmost that is hoped from her, and
we think rather more than will be obtained
Her engines are not powerful enough to make
her competitor in speed with the fast Collins
or Cunard steamers. For that, she must have
larger cylinders. The means of increasing
power is to enlarge the diameter of the cylin-
ders. When these engines were built, Captain
Ericsson desired to have cylinders of l6 feet
but no establishment would undertake to cast
them, and Ia were the largest he could get
Now Messrs. Hogg & Delamater are ready to
make them of any size required at their own
risk
The smoothness with which the engines
worked was remarkable. Capt. Ericsson said
that u ID. pressure was enough to move them.
The amount of friction he finds very much less
than he anticipated. The coal consumed by
the whole four furnaces is at the rate of tons
in "a hours 7 tons is the utmost limit of their
consumption. The engineer and one fireman
suffice to tend the whole mechanism There ia
no unpleasant smell, as about steam machine
ry There are two smoke pipes and two pipes
to carry off the escaped air. These pipes
are IL feet above the deck, and 80 inches in
diameter. They are painted white, with gilt
rim at the top, but there is not smoke enough
to suliy them. The amount of air passing
through these four cylinders in an hour Is
from so to rs tons This keeps the ship per-
fectly ventilated. 1t was cool and pleasant in
the Immediate vicinity of the furnaces.
Neu York Tribune