A patent print poster of an Adding Machine invented by Willis A. Kropp and assigned to the Victor Adding Machine Company. The patent was issued by the United States Patent Office on June 30, 1939. An adding machine was a class of mechanical calculator, usually specialized for bookkeeping calculations and were pretty much found in every office until the 1970s.
Patent prints allow you to have a piece of history in your home, office, man cave, geek den or anywhere you wish to add an interesting touch.
