THE SEARCH EOR A NEW SOLAR OBSERVATORY SITE 



By C. G. ABBOT 



Secretary of the Smithsonian Institution, and Director of the Smithsonian 



Astrophysical Observatory 



The sun's radiation varies in a combination of five regular periods. 

 Such is the harmonious result of exact independent observations made 

 at three stations in California, Chile, and South West Africa. There 

 are strong indications that these solar variations affect temperature 

 conditions all over the world. At present the results of the Chilean 

 station are far better than those of the other two, owing to the excep- 

 tional clearness and steadiness of sky conditions there. 



A friend of the Institution became strongly impressed with this ap- 

 parent correlation between solar variation and weather. He believed 

 that before long the Observatory would be called on to furnish solar- 

 radiation values of highest accuracy on ever)' day of the year, for 

 the use of official weather bureaus of all countries. He therefore made 

 a grant of $28,000 to enable the Institution to keep a trained observer, 

 A. F. Moore, in the field for a whole year, testing high altitude desert 

 stations and seeking to find another in the Old World as favorable 

 as Montezuma, Chile. It was hoped that such a station could be found 

 where observations of Montezuma on many days could be duplicated, 

 and many days lost by clouds at Montezuma could be filled in by ob- 

 servations under fine sky elsewhere. 



Mr. and Mrs. Moore visited Fogo Island in the Cape Yerde group, 

 and made daily observations on a high peak there for over a month. 

 Though generally cloudless, this mountain proved to be surmounted 

 by a very high thick blanket of haze nearly all the time, which seems to 

 arise in the Desert of Sahara. Disappointed here, Mr. and Mrs. Moore 

 went on to South West Africa, where they occupied Mounts Lord, 

 Erongo, Gansberg, Grosskopf, and attempted the Brandberg unsuc- 

 cessfully. Some of these stations were occupied for several weeks on 

 two separate occasions, and their skies were compared with those 

 of Mount Brukkaros where regular observations were going on. 

 Although some of these South West African peaks proved a 

 little superior to Brukkaros, they lacked much of the excellency of 

 Montezuma. 



Funds for continuation of Mount Brukkaros station being now 

 nearly exhausted, and no station of much better character being found 



