SIBERIAN ECLIPSE OF SUN WILL BE STUDIED

Science's most modern instruments for detecting rare chemical gases and elements will be used by Harvard and Massachusetts Institute of Technology scientists to follow every phase of the eclipse of the sun in Siberia, June 19. Donald H. Menzel, assistant professor of Astronomy, will head the Harvard-Technology solar expedition which leaves for Russia this spring.

Whether the sun contains a mysterious element "coronium," unknown to the earth, or whether the phenomenon giving rise to the coronium theory is merely the reaction of a well known element such as oxygen under peculiar conditions on the sun, is one of the many important scientific problems which the Harvard-Technology instruments have been designed to solve.

The scientists plan to obtain spectrograms of the outer layers of the sun's atmosphere and of the brilliant corona over a wide range of wave lengths. They will study especially the infra-red region of the spectrum, where present knowledge is only fragmentary.

In order to make the expedition's delicate instruments suitable for the exacting conditions of field work, many of them are being constructed of dowmetal, an extremely light and rigid new alley, Dr. Menzel stated.

Two dowmetal spectrographs will be used to follow the course of the changing spectrum of the sun throughout the progress of the eclipse. They will record the appearance of the spectrum on a moving plate.