"Hollow Square" Conferences, Talks on Astronomy Planned

Weekly colloquia and "hollow-square" conferences have been scheduled by the staff of the Harvard Observatory to take place on Tuesday evenings for lectures on such subjects as theories of stellar evolution and the temperature of the earth's upper atmosphere.

The first will be held June 30 at 8 o'clock in the observatory library, when Dr. G. P. Gaposchkin will speak on "The Present Status of Theories of Stollar Evolution." On July 7 Dr. Harlow Shapley, Paino Professor of Practical Astronomy, will conduct a hollow square conference and the following week a special colloquium is planned to commemorate the work of Dr. A. B. Wyso. Hollow Square conferences will be held on July 21 and August 4, and on July 28 Dr. F. L. Whipple will speak on "Densities and Temperatures in the Earth's Upper Atmosphere." Plans for the second summer school session have not been announced.