The Puckle Gun 1700s
While rapid fire weapons are generally thought of as a 19th Century invention, James Puckle patented a rapid fire gun in 1718!
Check out this image of the gun from his patent: http://www.wedmore.org.uk/puckle/James.htm A bit more information on the gun can be found at http://www.ccrkba.org/pub/rkba/news/PuckleGun.htm