A refined form of Grape Shot, Canister Shot was seen in the late 18th Century. Designed as a metal container primed with gunpowder, the construction held multiple iron small slugs or balls (as little as 40 and as many as 110). When fired, (and at the desired elevation), the timed fuse would ignite. The resulting explosion would release the balls in various directions. Maximum casualties were inflicted by The Canister Shot. Another example of a “Shotgun” burst device, Canister was very effective against infantry and cavalry charges. Navies adopted The Canister as a more effective projectile (over Grape Shot). A tactic known as “Double Canister” involved the addition of a threaded screw hole applied to the top of the shell. Multiple shells could then be attached and fired – creating an enormous projectile of mass destruction.