I need recommendations for references on the processes of gun powder
production during the 18th and early 19th centuries.  Particularly helpful
would be diagrams, schematics, and drawings or pictures of
machinery/production equipment.  But I'd happily settle for a good book!
Many thanks.

Matthew S. Tomaso, M.A., R.P.A.
Coordinator, Center for Archaeological Studies
Director, Feltville Archaeology Project
Earth and Environmental Science Faculty