Smithsonian Report, 1933. — Abbot 



Plate 4 



1. Montezuma, Chile, solar Observatory, Altitude 9,000 Feet. 



The coelostat at right reflects the solar beam into the tunnel to the spectrobolometer. In the center are 

 shown the two silver-disk pyrheliometers for observing total solar radiation. At the left the observer 

 measures the sun's altitude 



t^&kJi^^ 



2. SMITHSONIAN SOLAR OBSERVATORY ON MOUNT ST. KATHERINE. SINAI PEN- 

 INSULA, Egypt. Altitude 8,500 Feet. 



Observatory on the peak, dwelling below. The director, his wife, two infants, and the assistant occupy 



this desolate station. 



