A model of an electromagnetic engine.
Inventors today have got it easy. If they want to patent something, all they have to do is file some paperwork. Before 1880, however, if you wanted to patent a better mousetrap, you actually had to build it – or at least a miniature version to help patent inspectors understand why you actually deserve the patent…
2006 article about the Rothschild Patent Model Museum in Forbes
Photo above – Rothschild Patent Model Collection, Scherzi Photography