I believe it's a glockenshpiel actually. It's a little hand held instrument that, when cranked, a wooden stick clicks up againt the teeth on a metal geat, thus making a "clack clack clack" noise, much like a gattling gun, or a baseball card clicking against the spokes of a bike tire.
The Museum of Natural Science is in Houston, Texas in our museum district. The exhibit ended a couple weeks ago, though. It was the must successful temporary exhibit the museum has ever presented.