the only differences being the size of the gun. They were all smoothbore guns designed to fire spherical shot and shell, primarily against ships. The guns were elevated and depressed by means of a lever called the elevating bar. The point of this lever fits into ratchets on the earliest guns cast, or sockets on the later guns. The fulcrum, called the ratchet post, fit on the rear transom of the upper carriage. The ratchet post was cast iron and had several notches for adjusting the position of the elevating bar. Only one 13-inch Rodman gun appears to have been made, but it was placed in service. Two 20-inch Rodman guns were emplaced at Fort Hamilton, New York. A third, shorter 20-inch gun was cast for USS Puritan using the Rodman technology. One 20-inch Rodman gun remains in a park just north of Fort Hamilton, and another is at Fort Hancock, Sandy Hook, New Jersey. The other, smaller Rodman guns were placed in seacoast fortifications around the United States. It took 8 men to load and fire a 10-inch Rodman gun, and 12 men for a 15-inch Rodman gun. Over 140 Rodman guns survive today. They may be seen at coastal fortifications around the country. Use Rodman guns saw little action during the Civil War. Two 10-inch columbiads were used in 1864 and 1865 in Union operation against Fort Sumter. It seems likely, due to the time period in which they were used, that these were Rodman guns rather than earlier model columbiads. Other reports of the use of 8-inch and 10-inch columbiads may refer to Rodman guns. The 15-inch Rodman guns were never fired in anger; however, they were widely deployed in coast defense until replaced by Endicott Period fortifications 1895–1905. Some Rodmans of various sizes, along with Parrott rifles, were deployed shortly after the outbreak of the Spanish–American War in 1898 as a stopgap; it was feared the Spanish fleet would bombard the US east coast. The 20-inch Rodmans were only fired eight times in practice to determine the effect of the projectiles. It was nearly impossible to find a target that would leave enough evidence to measure the effect of hits. The first four shots were fired with charges of 50, 75, 100, and of gunpowder, reaching a bore pressure of . Four more shots were fired in March 1867 with charges of 125, 150, 175, and