HARVARD MEN VIEW SUN ECLIPSE ON EXPEDITION

Two Harvard Sophomores, W. M. Powell Jr. and C. A. Rubel, were among the 15 members of the Sproul Observatory Expedition which journeyed from Swarthmore, Pa., to Yerlaniz, Mexico, early in July to observe the eclipse of the sun, which took place September 10.

The expedition, which was sent out by the Rubel Foundation, was under the leadership of Dr. J. A. Miller, head of the departments of Astronomy and Mathematics at Swarthmore. Among other numbers of the expedition were Dr. H. C. Curtis of the Alleghany Observatory, Pittsburg, Pa., Dr. R. W. Mariotte, and Dr. W. H. Wright, both of Swarthmore.

On July 18 the expedition reached Yerlaniz, a small Indian village in the province of Durango. The members of the expedition were forced to live in tents for the next two months because the village contained only the mud huts of about 100 Indians. Most of this time was spent in preparing apparatus for taking data on September 10, the day of the eclipse.

A camera sixty-five feel long, used for photographing the sun during eclipse was among the apparatus used by the expedition, which has been called by Dr. Miller the "best equipped single expedition that has ever gone out to observe an eclipse of the sun." Other apparatus included a two flash spectroscope with which to obtain spectra of the corona,--the gaseous haze surrounding the dark disc during totality; an Einstein camera, the gift of Professor C. L. Poor of Columbia, and especially adapted to proving the Einstein gravitational theory, and a new type of interferometer called the "etalon", designed to detect motion in the Corona. In addition the apparatus included a moving picture machine with which the first films ever taken of an eclipse were obtained.

Clouds Interfere With Pictures

On the morning of the eclipse, faint clouds may have spoiled some of the Einstein plates. A far more serious difficulty was encountered in the Indians who at first were determined to prevent the observations, thinking them some sort of a religious rite which might offend the native rain god. On being assured of the good intentions of the observers, however, the natives became even more objectionable in their desire to look through the telescopes.

The regular photographic plates and the motion picture films developed very successfully, and are now being exhibited in America. The success of the Einstein plates however cannot be determined until they have been carefully measured in the laboratories of Dr. Miller in Swathmore.