Cam-based Mathematics

This is an awesome old-school style video demonstrating how simple cam-based mechanical systems can be implemented to process numbers.

http://www.youtube.com/watch?v=-F7m02XDfvE

Calculating reciprocals, squares, and tangents using rotating disks:  it’s amazing stuff!  I wish I had seen (and appreciated) something like this as a young student.  It might have made me appreciate engineering a little more.

Be sure to check out the barrel cam at the end that is used to compute gun elevation.  I imagine something like this is at the heart of the mechanical calculators out there.