ting a portion of the enemy line with case-shot fire, covered
the assault so effectively that columns of cavalry and infantry
reached the gap without striking a blow!

After Napoleon, the history of artillery largely becomes a record of
its technical effectiveness, together with improvements or changes in
putting well-established principles into action.

UNITED STATES GUNS OF THE EARLY 1800's

The United States adopted the Gribeauval system of artillery carriages
in 1809, just about the time it was becoming obsolete (the French
abandoned it in 1829). The change to this system, however, did not
include adoption of the French gun calibers. Early in the century cast
iron replaced bronze as a gunmetal, a move pushed by the growing
United States iron industry; and not until 1836 was bronze readopted
in this country for mobile cannon. In the meantime, U. S. Artillery in
the War of 1812 did most of its fighting with iron 6-pounders. Fort
McHenry, which is administered by the National Park Service as a
national monument and historic shrine, has a few ordnance pieces of
the period.

[Illustration: Figure 10--U. S. 32-POUNDER ON BARBETTE CARRIAGE
(1860).]

During the Mexican War, the artillery carried 6- and 12-pounder guns,
the 12-pounder mountain howitzer (a light piece of 220 pounds which
had been added for the Indian campaigns), a 12-pounder field howitzer
(788 pounds), the 24- and 32-pounder howitzers, and 8- and 10-inch
mortars. For siege, garrison, and seacoast there were pieces of 16
types, ranging from a 1-pounder to the giant 10-inch Columbiad of
7-1/2 tons. In 1857, the United States adopted the 12-pounder Napoleon
gun-howitzer, a bronze smoothbore designed by Napoleon III, and this
muzzle-loader remained standard in the army until the 1880's.

The naval ironclads, which were usually armed with powerful 11- or
15-inch smoothbores, were a revolutionary development in mid-century.
They were low-hulled, armored, steam vessels, with one or two
revolving turrets. Although most cannonballs bounced from the armor,
lack of speed made the "cheese box on a raft" vulnerable, and poor
visibility through the turret slots was a serious handicap in battle.

[Illustration: Figure 11--U. S. NAVY 9-INCH SHELL-GUN ON MARSILLY
CARRIAGE (1866).]

While 20-, 30-, and 60-pounder Parrott rifles soon made an appearance
in the Federal Navy, along with Dahlgren's 12- and 20-pounder rifled
howitzers, the Navy relied mainly upon its "s