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SCOUTING FOR A SITE FOR A SOLAR-RADIATION 

 STATION 



By a. F. MOORE, 



Astrophysical Observatory, Smithsonian Institution 



(With 4 Plates) 



During the early part of 1930 it became apparent that if measure- 

 ments of the solar constant of radiation were to be made by the 

 Smithsonian Institution with sufficient accuracy on a large percentage 

 of the days of the year to make possible dependable analyses of the 

 various cycles included in the changes in the sun's radiation, it would 

 be very desirable, if not necessary, to find a location for a solar- 

 radiation station in the Eastern Hemisphere, which would be nearly, 

 if not quite the equal of the Montezuma station in northern Chile. 

 This was becoming all the more desirable because of the increasing 

 interest being manifested in the investigation of the possibility of 

 weather forecasting, particularly long-range forecasting, by means of 

 changes in solar radiation. 



In 1930 the Smithsonian Institution was operating three solar sta- 

 tions in widely separated parts of the globe, viz : on Mount Montezuma 

 in the Atacama Desert of northern Chile; on Table Mountain in the 

 Sierra Madre range, bordering upon the Mojave Desert in southern 

 California ; and on Mount Brukkaros in the south-central part of 

 Southwest Africa. The Chilean station was established near Calama 

 in 1918 and two years later was moved to Mount Montezuma, where 

 it has since been in continuous operation. Its elevation is about 9,000 

 feet above sea-level, and the large percentage of clear, uniform skies 

 found there has not been equalled elsewhere to date. The Table 

 Mountain station was moved to its present site in 1925, from Mount 

 Harqua Hala in western Arizona where it had been located since 

 1920. Table Mountain is 7,500 feet above sea-level, and although 

 the percentage of observable days approximately equals that of the 

 Chilean station, the quality of the skies, particularly as regards uni- 

 formity, falls considerably short of that of the latter. Observations 

 were begun at Mount Brukkaros in 1926, and this station was built 

 and operated for about four years under a grant from the National 



Smithsonian Miscellaneous Collections, Vol. 89, No. 4 



