the chemist Russell S. Penniman invented "ammonium dynamite", a form of explosive that used ammonium nitrate as a substitute for the more costly nitroglycerin. Ammonium nitrate has only 85% of the chemical energy of nitroglycerin.

It is rated by either "weight strength" (the amount of ammonium nitrate in the medium) or "cartridge strength" (the potential explosive strength generated by an amount of explosive