With Rodman's gun, the muzzle-loading smoothbore was at the apex of
its development. Through the years great progress had been made in
mobility, organization, and tactics. Now a new era was beginning,
wherein artillery surpassed even the decisive role it had under
Gustavus Adolphus and Napoleon. In spite of new infantry weapons that
forced cannon ever farther to the rear, artillery was to become so
deadly that its fire caused over 75 percent of the battlefield
casualties in World War I.
Many of the vital changes took place during the latter years of the
1800's, as rifles replaced the smoothbores. Steel came into universal
use for gun founding; breech and recoil mechanisms were perfected;
smokeless powder and high explosives came into the picture. Hardly
less important was the invention of more efficient sighting and laying
mechanisms.
The changes did not come overnight. In Britain, after breechloaders
had been in use almost a decade, the ordnance men went back to
muzzle-loading rifles; faulty breech mechanisms caused too many
accidents. Not until one of H.M.S. _Thunderer's_ guns was
inadvertently double-loaded did the English return to an improved
breechloader.
The steel breechloaders of the Prussians, firing two rounds a minute
with a percussion shell that broke into about 30 fragments, did much
to defeat the French (1870-71). At Sedan, the greatest artillery
battle fought prior to 1914, the Prussians used 600 guns to smother
the French army. So thoroughly did these guns do their work that the
Germans annihilated the enemy at the cost of only 5 percent
casualties. It was a demonstration of using great masses of guns,
bringing them quickly into action to destroy the hostile artillery,
then thoroughly "softening up" enemy resistance in preparation for the
infantry attack. While the technical progress of the Prussian
artillery was considerable, it was offset in large degree by the
counter-development of field entrenchment.
As the technique of forging large masses of steel improved, most
nations adopted built-up (reinforcing hoops over a steel tube) or
wire-wrapped steel construction for their cannon. With the advent of
the metal cartridge case and smokeless powder, rapid-fire guns came
into use. The new powder, first used in the Russo-Turkish War
(1877-78), did away with the thick white curtain of smoke that plagued
the gunner's aim, and thus opened the way for production of mechanisms
to absorb recoil and return the gun automatically to firing position.
Now, gunners did not have to lay the piece after every shot, and the
rate of fire increased. Shields appeared on the gun--protection that
would have been of little value in the days when gunners had to stand
clear of a back-moving carriage.
During the early 1880's the United States began work on a modern
system of seacoast armament. An 8-inch breech-loading rifle was built
in 1883, and the disappearing carriage, giving more protection to both
gun and crew, was adopted in 1886. Only a few of the weapons were
installed by 1898; but fortunately the overwhelming naval superiority
of the United States helped bring the War with Spain to a quick close.
[Illustration: Figure 15--Ranges.]
During this war, United States forces were equipped with a number of
British 2.95-inch mountain rifles, which, incidentally, served as late
as World War II in the pack artillery of the Philippine Scouts.
Within the next few years the antiquated pieces such as the 3-inch
wrought-iron rifle, the 4.2-inch Parrott siege gun, converted Rodmans,
and the 15-inch Rodman smoothbore were finally pushed out of the
picture by new steel guns. There were small-caliber rapid-fire guns of
different types, a Hotchkiss 1.65-inch mountain rifle, and Hotchkiss
and Gatling machine guns. The basic pieces in field artillery were
3.2- and 3.6-inch guns and a 3.6-inch mortar. Siege artillery included
a 5-inch gun, 7-inch howitzers, and mortars. In seacoast batteries
were 8-, 10-, 12-, 14-, and 16-inch guns and 12-inch mortars of the
primary armament; intermediate rapid-fire guns of 4-, 4.72-, 5-, and
6-inch calibers; and 6- and 15-pounder rapid-fire guns in the
secondary armament.
The Japanese showed the value of the French system of indirect laying
(aiming at a target not visible to the gunner) during the
Russo-Japanese War (1904-05). Meanwhile, the French 75-mm. gun of
1897, firing 6,000 yards, made all other field artillery cannon
obsolete. In essence, artillery had assumed the modern form. The next
changes were wrought by startling advances in motor transport, signal
communications, chemical warfare, tanks, aviation, and mass
production.