Click on search at the top of the page. Type in Grasshopper in the search window and the click on advance search. When the advanced search window opens scroll down and deselect search all, then click on Choose a board to search in, or search all when the list of places to search opens under black powder forums select only Blackpowder Mortar and Cannon Sponsored by Seacoast Artillery and then scroll down click search.
I got 4 pages of hits...but I don't know if what your looking for is in there.
You might also check Robert Muller's Treatise on Artillery.
