Artificial leg was patented by Benjamin Franklin Palmer in 1846. His invention received patent number 4,834. Children can read about Palmer and his invention at: Palmer.
Cash register was patented in 1879 by James Ritty and John Ritty of Dayton, Ohio. They invented the cash register, called “Ritty’s Incorruptible Cashier,” because they felt employees were stealing money from them. Children can see the patent at the Google patent site at: Cash Register Patent.
Refrigeration apparatus was patented by Thomas Elkins in 1879. He received patent number 221,222. Children can see his patent at the Google patent site at: Refrigeration Patent.