Contents

03 November 1972
Vol 178, Issue 4060

About The Cover

Artificial cloud formed by introducing 5 kilograms of Dry having more water vapor than would be present at ice saturation. As Dry Ice powder was released from an aircraft, cloud cells were formed which later merged into a uniform cloud. Cloud shown was photographed 20 minutes after seeding. See page 504. [T.Ohtake, Geophysical Institute, University of Alaska,Fairbanks]