Rick, I just dug out my copy of Ordinance and Gunnery, 1862, and it says that: "The stone mortar is employed in siege operations to precipitate a large mass of stones, or hand-grenades, upon the heads of the enemy in the advanced trenches, or, in like manner, to clear the breach of defenders, preparatory to an assault. Dimensions, &c. The diameter of the bore is 16 inches, and it's length is about 1 1/4 times it's diameter. It's chamber is conical and the charge of powder for 120 pounds of stones is 1 1/2 Lbs; and for fifteen 6-pdr. shells, it is 1 Lb. It is made of bronze, and mounted on a bed similar to that for a 10-inch mortar." All this from page 188 along with a note that the stone mortar has been removed from the list of New Cannons.
I have never read of an action where this type of mortar was used, although that is certainly possible. I also remember a comment from an artillery officer, in that, the employment of this type, loaded with a wicker-basket of short fused, 6-pdr. shells would most certainly be as dangerous for the gun's crew as it was for the enemy! Think about it!
I believe I saw one at West Point in 2004.
Regards,
Tracy
