The elusive Columbiad

this is a bit OT, but educational: could someone explain to me what a
'columbiad' is? i sort of assumed it was an epic journey to Columbia,
probably written in iambic pentameter :).

A Columbiad was, in the American artillery vernacular of the 1840-60's,
a
smoothbore cannon, mostly of 8 and 10 inch caliber capable of firing
explosive shell as well as solid shot.	In the British service such
weapons
were generally refered to as Paixhan guns after the French designer who
pioneered the shell firing gun.  By the time of the Civil War things get
really confusing with Columbiads, Rodmans, and Dahlgrens (the last two
similar to Columbiads but of improved "coke bottle" shape), Parrot
rifles,
Brooke Rifles, Armstrongs and Whitworths, Napoleons and on and on...