Mystery Item Answer--Mandoline

This is a mandoline or kraut cutter which is used to slice vegetables. 

 I used the one in the photo at the 1837 Hofauger House at Virginia's Explore Park in Roanoke, Virginia when I demonstrated fireplace cooking.  I used to tell visitors that it was the early "Veg-O-Matic!"

You might even have one in your kitchen right now, but it is probably made of plastic or metal.