Last week I wrote about the Eyeballing game, an applet that tests your visual accuracy. It was created by a woodworker.

Well, as I was perusing his website I found another neat mathematical creation. He made a binary marble adding machine. He created this video showing it in action.

I encourage you to visit his website. He has built many other intricate wooden machines, such as a combination lock, tank treads, tripods, an apple grinder, a pipe organ and other marble machines.