The carronade was a short gun developed by the Carron Company , a Scottish ironworks , in 1778 for the Royal Navy. Also known as a smasher, it was a smoothbore, cast iron weapon, half the weight of an equivalent long gun, but could throw a heavy ball, for instance 68 pounds, over a limited distance. Carronades weren't counted in the ships rated number of guns.

Because of irregularities in the size of cannon balls and the difficulty of boring out gun barrels there was usually a considerable gap between the ball and the bore - often as much as a quarter of an inch - with a consequent loss of efficiency. This gap was known as the "windage". The manufacturing practices introduced by the Carron Company reduced the windage considerably.

The carronade was mounted on a sliding carriage with ropes to restrain the recoil. Lack of range against an opponent who could keep well clear and still use his long guns led to its disappearance in the Royal Navy from the 1850s with the development of steel, jacketed cannon by William George Armstrong and Joseph Whitworth. A few experimental ships were fitted with a carronade-only armament but suffered because enemies could stay outside their range.

Originally from http://www.cronab.demon.co.uk/gen1.htm, with the author's permission.