Columbiad

This feature enabled the columbiad to fire solid shot or shell to long ranges, making it an excellent seacoast defense weapon for its day.

Although some Second System forts were armed with this weapon, the Army did not widely adopt early columbiads due to initial high costs of manufacture.

[1]: 61 Just prior to the American Civil War, Ordnance Corps officer Thomas Jackson Rodman developed an improved version of the columbiad, which became known by his name.

The process involved ensured the iron cooled evenly from the inside out, and resulted in what we might call today a "soda bottle" shaped casting with smooth, tapered exterior.

The smaller-bore columbiads shared similar range factors to the older weapons, but the fifteen-inch (381 mm) models weighed over 25 tons and could fire 400-pound projectiles out to 5,000 yards (4,600 m).

Strapped for funding, the post-war army continued to carry smooth-bore columbiads on inventory lists until after the Spanish–American War, when modern breech-loading rifled cannon replaced them.

The cannon is then loaded with 400,000 pounds (180,000 kg) of "pyroxyle" (gun cotton) to give the projectile sufficient velocity to leave Earth's atmosphere and reach the Moon.