y means of heat. The invention consists of a
double furnace mounted on wheels, which are incased in the fire boxes of
the furnace, so that in use the entire apparatus, including the wheels,
will become highly heated, so that the snow and ice will not only be
melted by radiant heat, but by the actual contact of the hot surfaces of
the furnace and wheels. This apparatus was recently patented by the late
E. H. Angamar, of New Orleans, La.

[Illustration: APPARATUS FOR REMOVING ICE FROM RAILROADS.]

* * * * *

ERICSSON'S NEW SUBMARINE GUN.

The protracted trials conducted on board the Destroyer to test its
submarine gun terminated last week. Having, says the _Army and Navy
Journal_, in a previous issue described this novel type of naval
artillery, it will suffice to remind our readers that its caliber is 16
inches, length of bore 30 feet, and that it is placed at the bottom of
the vessel, the muzzle passing through an opening formed in the wrought
iron stem.

We have hitherto, in discussing the properties of the Destroyer,
referred to its offensive weapon as a "torpedo," a term not altogether
inappropriate while it was actuated by compressed air. But Capt.
Ericsson having in the meantime wholly abolished compressed air in his
new system of naval attack, substituting guns and gunpowder as the means
of producing motive energy, it will be proper to adopt the constructor's
term, _projectile_. It will not surprise those who are acquainted with
the laws of hydrostatics and the enormous resistance offered to bodies
moving swiftly through water, that the determination of the proper form
of projectile for the submarine gun has demanded protracted experiments,
commencing at the beginning of June and continued up to last week, as
before stated. The greater portion of these experiments, it should be
observed, has been carried out with a gun 30 feet long, 15 inches
caliber--not a breech-loader, however, as in the Destroyer, but a
muzzle-loader, suspended under the bottom of two wrecking scows, the gun
being lifted above the water, after each shot, by shears and suitable
tackle. The present projectile of the Destroyer is the result of the
extended trials referred to; its length is 25 feet 6 inches, diameter 16
inches, and its weight 1,500 pounds, including 250 pounds of explosive
materials. We are not at liberty at present to describe its form, but we
may mention that the great length of the bo