.36-caliber revolver, with 3.5", 4.5", 5.5" or 6.5" barrel length and 5-shot cylinder. Has blued finish, wood grips and peculiar hump in its backstrap. First model has a safety device, which blocks the spur trigger. This device is found on serial numbers 1-100. Markings are: "C.R. Alsop Middletown, Conn. 1860 & 1861" on barrel; cylinder, "C.R. Alsop" & "Nov. 26th, 1861"; side plate, "Patented Jan. 21st, 1862".