NEED HELP INFO on French 58mm spigot mortar shell

does any one have any publications, photos, any info on the WWI era Trench mortars Thanks any help would be greatefully appreciated

jawasinger, this one is a French 58mm spigot mortar shell and the rod in the base is missing.
If I remember right the US had them also.

commons.wikimedia.org/wiki/Image … edoWWI.jpg

en.wikipedia.org/wiki/Image:Muse … G_0992.jpg