Gatling Gun –
Richard Jordan Gatling of the United Kingdom patented the gatling gun in 1862.
Gatling guns were produced by Colt Mfg from 1866 to 1909.
Gatling Guns came in 5, 6, and 10 barrels and 25 different calibers
This Gatling Gun, serial number 1152, was made in 1903.
The Gatling Gun is not a machine gun but a semi-automatic repeating rifle.
Reference obtained from The Gatling Gun Notebook by James B. Hughes

