Professor H. E. Edgerton of Massachusetts Institute of Technology will demonstrate "frozen motion" in ultrahigh speed photographs at an open meeting of the Harvard Engineering Society in Pierce Hall tonight at 7:30 o'clock. There will be no charge for admission.

Taken in brilliant flashes of light of as brief a duration as one one-millionth of a second, both still and motion pictures will be shown. Professor Edgerton will exhibit the equipment and explain the technique he employed in this particular branch of photography.

Raindrops Round

High speed photographs have revealed that the raindrop, contrary to the popular conception of it as the inspiration for the super-streamlined automobile, is spherical. These pictures enable biologists to study the movement of the humming bird's wings.

The strange, crown-like formation which splashing milk produces is caught by Professor Edgerton's camera. The entire stroke of a tennis racquet or golf club can be photographically dissected and analyzed.