http://www.rockislandauction.com/viewitem/aid/1025/lid/2194

Made in Naubuc Connecticut, the Hammond Bulldog was an interesting single-shot rimfire .44 caliber pistol. It used an unusual rotating breechblock, and had the potential to be a fairly strong action. Reportedly prototypes were made in a wide variety of calibers, including a carbine version with a wire-frame shoulder stock, but the vast majority were .44 caliber rimfire pistols like this one.