The Napoleonic Wargame by G W Jeffrey pub 1974 - definitely old school, complete with "bounce-sticks" and canister templates, but a worthwhile read which has made me think, particularly over how artillery batteries are represented on the wargame table.
I'm so happy I'm about to bust a gusset! Everything, including Windows 10 trying to load the cumulative update, fail and rolling back. All is right again in my little world. (Until I actually have to buy a new machine).