Designed by Christian Sharps (or Sharps rifle fame), the Sharps & Hankins carbine was a light and handy rimfire carbine intended for military use. It was a single-shot weapon with an unusual action to lever the barrel forward off the frame, and several interesting technical feature. Most significantly, it used a floating firing pin in the frame, instead of one directly connected to the hammer – a common practice today but novel in the 1850s and 60s.
This example is one of the carbines purchased by the US Navy, which included a distinctive leather sheath on the barrel. This was to protect against salt spray, although these days they are more of a liability for trapping moisture against the barrels, since few owners today expose the guns to ocean spray.