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guns and 45 batteries of heavy artillery (four guns to each battery),
including cannon provided for by Congress, and since then delivered.
There was an inadequate supply of ammunition for the heavy guns.

MUNITION SUPPLY AUGMENTED.

The ammunition supply was immediately augmented and field guns of
various calibers turned out as fast as possible, including 9-inch
howitzers.

A 3-inch field gun fires projectiles weighing 15 pounds, with a muzzle
velocity of 1700 feet per second.

A 4.7-inch field gun fires projectiles weighing 60 pounds, with the same
velocity.

A 6-inch howitzer fires projectiles weighing 120 pounds, with a muzzle
velocity of 900 feet per second.

The principal difference between the field gun and the howitzer is that
the latter can be pointed at a high angle, to assail infantry protected
by intrenchments, or for other purposes.

While reference has been made to siege guns, which were used by the
Germans in their attacks on the Belgian and French forts, the fact is
that the large caliber mortars and howitzers are what wrought the havoc.

The large caliber howitzers and mortars throw shells containing huge
charges of explosives, and are more adaptable in their application than
the ordinary siege guns or cannons.

One novelty which had not been used up to the entrance of the United
States into the war is a device invented by a Los Angeles man, which
makes a "periscope gun" of any ordinary service piece.

In trench warfare, as developed abroad, the periscope has been used by
the men in the trenches to observe the movements of the opposing forces
and watch for scouts without exposing themselves to the fire of
"snipers" or sharpshooters, who are always looking for a head or mark to
aim at.

The new device comprises two mirrors attached to the gun by a metal
frame in such manner that one mirror is above the range of vision and
reflects the image to be fired at upon the other mirror below the stock
or butt of the gun. The attachment enables the soldier sitting in a
trench or shelter to accurately aim his gun and conveniently shoot while
his head is kept below the safety line, or top of the parapet, or
properly built trench.

THE TRENCH PERISCOPE.

With this attachment, approved by the United States Ordnance Department,
a rifleman, from his concealed point of vantage, can survey a 30-foot
field at 200 yards. The attachment can be removed at will and the metal
bars and parts can be easily