Patent models from the Smithsonian

From an article at Salon:

Visitors to the nation’s capital were once able to stroll through the halls of the Patent Office, oohing and aahing over the tiny models inventors were required to submit as part of their patent applications. While the vast majority of these models — which at one point numbered in the hundreds of thousands — have since been destroyed in fires or otherwise lost to history, a small portion remains. An even smaller selection (32 in all) will be on display in Washington through November 2013.

At the top is the model of what appears to be a humane live trap for mice.  And here is a surpringly (to me, at least) complex mechanism for manufacturing horse shoes (?):

Salon includes a gallery of 13 examples.