What we now call Improvised Explosive Devices have had different names over the centuries that they have been used. Here’s one you may not have heard of. The word “caisson” has a range of meanings derived from the “sealed box” of its original meaning. Today a caission is associated with either the ammunition box used in support of an artillery piece, or a sealed box like structure sunk in water to allow engineering work to take place. But in 1778 “caisson” had this meaning, according to a military dictionary published that year:
