This is a wonderful old gadget I found 2 summers ago in an Antique shop in NC (Hendersonville, I believe). It works like a gem---you put the potato in and push the handle down and out pops the sliced potatoes.
If you bake them in the oven on parchment paper with your favorite spicy seasonings you don't even need oil!! It is one of my favorite snacks. They take about 20 minutes at 425-450 degrees. This is a wonderful time saving little gadget!! (However I always wonder about old gadgets--do they have lead??)