American engineer who invented the stroboscope, a device which uses a rapidly flashing light to take a rapid series of pictures at rates of up to 2000 frames per second. Not only does this technique have practical engineering applications, allowing examination of rotating objects by appearing to "stop" them by synchronizing the strobe light to their rotational period (the so-call strobe effect ), but it also makes for breathtaking imagery. The fascinating short film by P. Smith (1940) is perhaps the best chronicle of the stroboscope. Among other things, it shows the rotation of a fan and its effect on smoke, a golf ball being hit through a phone books, a cat lapping milk with the underside of its tongue, the popping a of bubble, the shooting of a bullet through a light bulb, the falling of milk drops, the beating of a hummingbird's wings, and even a dentist's drill!