This is the Strandbeest mechanism developed by Dutch artist and engineer Theo Jansen in the late 1980's. Combine a series of these mechanisms (out of phase) to create a walking machine. Jansen has built numerous Strandbeesten - most using wind power to turn the crank. Here is the basic configuration using the eleven Holy Numbers that describe the linkages. For this simulation, the green bar is fixed to the machine. Minor changes to the lengths can be made to explore the sensitivity of parameters. Javascript and HTML5, of course.