Commander Charles B. Momsen, United States Navy, inventor of the Momsen lung and one of the directors of the successful salvaging of the ill-fated submarine Squalus, will describe the salvaging operations at a lecture sponsored by the Harvard Engineering Society in 110 Pierce Hall on Friday evening at 8 o'clock.

Commander Momsen has been concerned with the safety provisions on submarines and was one of the first to appear at the scene of the Squalus when it sank off Portsmouth last May.

The use of helium-oxygen mixtures in deep diving has been investigated by Momsen and his associates. Such a mixture is believed to aid materially in reducing the risk of the "bends," the all-important obstacle to prolonged stay at considerable depths.