Origin of the Cannon.
The shotgun and rifle, the familiar weapons of the sportsman and the
foot-soldier, are not the ancestors of the cannon, as might be surmised.
On the contrary, the cannon was the predecessor of the musket and its
successors. The rifle, however, antedated the rifled cannon, the type of
modern artillery. We do not know when cannon first appeared, but it may
have been soon after the discovery of gunpowder in Europe. This
explosive seems to have been known in China long before knowledge of it
reached the west, but we do not know to what extent it was developed and
used in that country.
[Illustration: THREE-INCH FIELD GUN UNDER TEST AT FORT RILEY, KANSAS
In the trials conducted by the Board of Ordnance and Fortification of
the United States Army. This gun and carriage, complete, weighs 2,020
pounds. Charge, 18.5 ounces of smokeless powder. Weight of projectile,
15 pounds. Muzzle velocity, 1,800-foot seconds.
_Courtesy of the Bethlehem Steel Co._]
The earliest cannon of which we have any knowledge were clumsy
contrivances, at first wider at the mouth than at the chamber, and made
of wood, and later of iron bars, hooped together with iron rings, a
system of the same type as that now in use in the wire-wound cannon.
They at first seem to have fired balls of stone, iron balls coming
later. A doubtful statement exists to the effect that cannon were used
at the siege of Belgrade in 1073, and it is said that Edward III used
them against the Scotch in 1327. Other dates of their use are 1338 and
1346, in which latter year Edward III employed them against the French
at Crecy. For this we have the authority of Froissart. They were known
under the varied names of bombards, serpentines, etc. Twelve cannon cast
by Louis VII were named after the twelve peers of France, and Charles V
gave twelve others the names of the twelve apostles. Other titles came
later into general use, the royal or carthorne, carrying 48 pounds; the
culverin, 18 pounds; the demi-culverin, 9 pounds; the basilisk, 48; the
siren, 60, etc. In still later times cannon became known by the weight
and the balls they carried, 6-pounders, 12-pounders, etc. But they are
now usually called after the size of their bores, as 6-inch, 8-inch, or
12-inch cannon. The oldest example still in existence is “Mons Meg,”
preserved at Edinburgh Castle. This is one of the iron-bar type, hooped
by iron rings. It is supposed to have been used by James II of Scotland,
at the siege of Threave Castle in 1455.
[Illustration: THREE INCH NAVAL LANDING GUN, CARRIAGE AND LIMBER
Weight of gun and mechanism, 675 pounds. Length of gun, 74.35 inches (25
calibers). Weight of projectile, 13 pounds. Travel of projectile in
bore, 62.9 inches (20.97 calibers). Weight of charge, 18 ounces of
smokeless powder. Muzzle velocity, 1,650-foot seconds. Muzzle energy,
246-foot tons. Weight of gun, carriage, limber, drag ropes, tools, etc.,
and 60 rounds of ammunition, complete, 3,420 pounds. The carriage and
limber have each two removable interchangeable ammunition boxes for 12
rounds each, with a box for 12 rounds below the axle of the limber.
_Courtesy of the Bethlehem Steel Co._]
Louis VI used bombards of great length and power against the Flemish in
1477, while as early as 1401 bronze cannon had been cast in several
cities of West Prussia. Iron cannon were not cast until near the end of
that century. Coming down to the seventeenth century, we are told of the
great Bijapur cast-iron gun, the “Lord of the Plain,” cast by the Mogul
emperor Auremgzebe or by his foes the Mahrattas. This huge gun was 14
feet long, 28 inches bore, and fired a ball of 1,600 pounds weight.
Smooth-bore cannon and mortars of cast-iron and bronze are still
retained in some fortresses, though rifled cannon are the only type now
made. As late as 1864 smooth-bore 100- and 150-pounder wrought-iron guns
were made for the British navy and a few bronze rifled guns were made in
1870 for service in India, but all such guns are now obsolete.
[Illustration: TWENTY-EIGHT TON AUSTRIAN SIEGE HOWITZER WHICH FIRES A
THOUSAND-POUND PROJECTILE
The Germans borrowed a large number of these great siege pieces from the
Austrians and used them in the reduction of the Belgian defenses. Huge
shells filled with high explosives from these mammoth guns rapidly
destroyed the most modern and powerful fortifications known at the
beginning of the great war. It is known that against such weapons of
offense no fortifications can last and that the employment of such
weapons has forced both armies to depend on their trenches as their main
defense.]
[Illustration: CONQUERING THE ALPS.
Immense labor and great ingenuity were required to haul the monster
Italian guns up the steep mountain sides to their positions.]
[Illustration: THE MOST FORMIDABLE OF THE FRENCH ARMY’S TRENCH ARTILLERY
80-m.m. mountain gun loaded with air-mine weighing 130 pounds. These
mines can be thrown for a considerable distance and create havoc in the
enemy’s trenches if the aim is true.]
[Illustration: THE BENNETT-MERCIER MACHINE GUN
This new automatic machine gun has been adopted by the United States
Army, Navy and Marine Corps. It is handled by two men, one to aim and
fire it, the other to feed the cartridges which are held in brass clips
of 30 each. The complete gun weighs only about 35 pounds, fires 400
shots per minute, using regular 30-caliber Springfield rifle cartridges,
with a maximum range of 3 miles and an effective range of about 2,000
yards. The weapon is air cooled and can be fired steadily for about 10
minutes without undue heating.]
[Illustration: THREE-INCH FIELD GUN, LONG RECOIL CARRIAGE AND LIMBER
Weight of gun, carriage and limber complete, including 36 rounds of
ammunition, 4,200 pounds; ground clearance, 22.5 inches. Seats are
provided on axle of carriage for two gunners in transportation, one of
whom operates the road brake.
_Courtesy of the Bethlehem Steel Co._]
The development of the rifle from the old smooth-bore musket, by cutting
grooves or channels in the form of a screw in the interior surface, was
found so advantageous in increase of precision of aim and length of
range, that the rifling of cannon in time followed and is now
universally used. Breech loading has also replaced muzzle loading,
another vast advantage in the use of artillery. A form of breech-loading
cannon was introduced in the sixteenth century, but the advantageous use
of this device is of late invention. An important result of these
changes is the use of elongated instead of round balls, this permitting
of the employment of much heavier projectiles for the same width of
bore.
Modern Cannon.
Until 1888 the largest cannon in use was the 119-ton Krupp, made in 1884
for Italy; but in 1888-90 the same house produced a 135-ton gun for
Cronstadt. The heaviest British gun at that time was of 111-ton weight.
This threw a projectile of 1,800 pounds with a muzzle velocity of 2,216
feet per second. But there later came a reaction in favor of lighter
guns and quick firers. The heavy cannon of recent times are not cast, as
of old, but are made of forged-steel by what is known as the building-up
process. The different parts of these are called the tube, jacket,
hoops, locking rings, trunnion rings, wire winding, etc.
Cannons are subject to great stress in firing, this being of two kinds.
One is the longitudinal stress, acting in the direction of the length
and tending to pull the muzzle away from the breech. The other is the
circumferential or tangential stress, which tends to split the gun open
in lines parallel to the axis of the bore. These stresses are results of
the longitudinal and radial pressures of the gas developed by the
ignition and explosion of the powder. Such destructive forces have to be
guarded against in the building of a cannon and have led to a great
development over the old-time casting processes. As long as projectile
velocities under 1,500 feet per second were employed cannons cast in one
piece sufficed, but when greater velocities were sought, the pressure
grew so extreme that no cast or forged metal tube would stand the
strain.
[Illustration: THREE-INCH MOUNTAIN GUN AND CARRIAGE
Weight of gun, 206-1/2 pounds. Length of gun, 37.25 inches (12.4
calibers). Weight of projectile, 12 pounds. Travel of projectile in
bore, 27.55 inches (9.2 calibers). Weight of charge, 12.5 ounces of
smokeless powder. Muzzle velocity, 1,224-foot seconds. Muzzle energy,
123-foot tons. Weight of gun and carriage complete, 726 pounds. This gun
and carriage break up into four loads of approximately 200 pounds each.
The equipment carries 16 complete rounds of ammunition with it, which
are divided equally among four boxes. The saddles are so made that the
load will go on any saddle.
_Courtesy of the Bethlehem Steel Co._]
How Cannon are Now Made.
It was found that the inner surface of the tube stretched more than the
outer surface, and that after the inner surface had been stretched to
its limit of elasticity the outer part failed to add to its strength, so
that further thickness was of no benefit. To do away with this
condition cannon were constructed on the principle of varying
elasticity, the metal with the greatest elongation within its elastic
limit being placed next to the bore, yet in high-powered guns this
system failed to yield the result desired and it was replaced by what is
known as the initial tension system. This comprised two methods: the
plain built-up gun and the wire-wound gun. In the latter certain parts
of the gun were wrapped with wire in the form of a ribbon.
[Illustration: RAPID-FIRE GUN
Six-inch rapid-fire gun equipped with patented two-handed elevating
gear, consisting of two hand wheels on opposite ends of the same shaft,
the handles being 180 degrees apart. The pointer uses both hands in
elevating and depressing the gun. The electric firing trigger _A_ is
worked by the index finger of the right hand without releasing the
handle. There is a second firing handle _B_ attached to the slide, for
firing either electrically or percussively.
_Courtesy of the Bethlehem Steel Co._]
Built-Up and Wire-Wound Guns.
A built-up gun is made of several layers of forged steel. The parts of
such a gun are known as the liner, the tube, the jacket and the hoops.
The liner is a single piece which extends the length of the bore and is
intended to contain the rifling and the powder chamber. This is inclosed
by the tube, which is also in one piece, surrounding the liner
throughout its length. Outside this is the jacket, made in two pieces
and shrunk on the tube. Over the jacket lie the hoops, six or seven of
these being used in a big gun. Like the jacket, these also are shrunk
on. All these parts are made of the finest quality of open-hearth
steel.
[Illustration: FIVE-INCH NAVAL GUN AND MOUNT
The latest type of gun used in the U. S. Naval Service in the secondary
batteries on a battleship.]
[Illustration: COAST DEFENSE GUN
A modern 14-inch coast defense gun at Sandy Hook. The gun is mounted on
a disappearing carriage, which lowers it out of sight behind the
breastworks after firing. This is one of the most powerful guns in the
world, firing a projectile which would pierce the armor of a battleship
more than five miles away.]
[Illustration: _Copyright by Underwood & Underwood, N. Y._