What is it? Game 39

This week's collaboration with What is it? Blog brings us this strange contraption - can you guess what it is?

Since no one guessed correctly in last week's game, we'll carry over the prize (a Free Live! Pro Webcam by Creative). It's not the latest gizmo, but hey - it's free!

Contest rule is darned simple: place your guess in the comment section. One guess per comment, but you can guess as many times as you'd like. Please post no URL - let others play. The first person who guessed correctly will win the webcam. If you live outside of the US or Canada, however, the prize is a Neatorama T-shirt instead.

For more clues (like dimensions and such), check out the What is it? Blog.

Come on, people! Let's win something already... Good luck!

Update 9/28/07 - The answer is:

Mechanical lifting jack for use on wagons and carriages. The rack-plate on the right is the fulcrum, while the one on the left serves as a catch.

From the patent:

...principally intended to be used for elevating and supporting either end of the axles of various kinds of vehicles prepatory to removing the wheels therefrom for the purpose of applying some lubricating material to the journals of said axles.