Rodman guns

Rodman, Thomas Jefferson (1815—1871). An American who was graduated from West Point (1841) and was appointed to serve in various Arsenals where his expts in the manuf of guns soon brought him into prominence. His method of casting guns on a hollow core, the metal being cooled by a stream of w, was adopted in 1847... 

Rodman published Properties of Metals for Cannon and Qualities of Cannon Powder in Boston in 1861. In his expts with the 15-inch gun that bears his name he developed the principle of special powders , ie, that there is a certain definite relation between the size, form and d of a powder that would give the best powder for a given gun in other words, a powder that would give the highest velocity for a given pressure. 

Lieut. Metcalfe s device is to measure the recoil by substituting for springs a material of uniform resistance, such as copper or lead, and measuring the recoil by means of a cut made in the material by a Rodman knife Interposed between the metal and the butt of the gun. 

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