The Fragile Forts
Thanks, I will look for that one.
Off the top of my head, my favorites include, in no particular order,
Peterson, ROUND SHOT AND RAMMERS
Manucy, ARTILLERY THOUGH THE AGES (avl on web)
Tucker, ARMING THE FLEET
Ripley, ARTILLERY AND AMMUNITION OF THE CIVIL WAR
Miller, volume ??, one of famous 10 vol series FORTS AND ARTILLERY
Blackmore, THE ARMOURIES OF THE TOWER OF LONDON
who? GUNS, AN ILLUSTRATED HISTORY OF ARTILLERY (see recent post for details)
Muller, A TREATISE OF ARTILLERY (avl in reprint and paperback)
Toussard, AMERICAN ARTILLERISTS COMPANION (classic 3-vol set, reprint by Greenwood press, one large one of plates, vol 3, just the plates volume is well worth getting if that's all you can find)
Kiley, Kevin NAPOLEONIC ARTILLERY
Abels, Robert CATALOG OF THE BROWN COLLECTION of cannons (thin paperback on slick paper has a few large and hundreds of small cannons from wealthy Mr. Brown's collection that Abels was selling off in 1970's as I recall, long out of print but many copies floating around, it is well worth $20-$40 in my opinion)
South Bend Replicas CATALOG of replica ordnance (any edition, catalog has enough small pictures of cannons around the world for me to consider it a valuable reference book in itself, it even has pictures of stuff in my collection)
there are more but that's all I have time to put here now, that'll give you a start anyway.