30 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. JO 



of meteorological observations there in former years led us to hope 

 for an even larger proportion of favorable sky conditions. However, 

 in many parts of the world the past two years have been exceptional 

 in their weather and it is to be expected that these exceptional con- 

 ditions affected the weather of the Nitrate Desert of Chile as well. 

 We therefore hope that in future years even better results may be 

 obtained than now. 



The purpose of the work is to follow the variations of the sun and 

 to lay a foundation for the application of such measurements to the 

 prediction of terrestrial temperatures. That branch of the investi- 

 gation has been taken up by Dr. H. H. Clayton of the Meteorological 

 Service of Argentina. Dr. Clayton has studied the correlations 



Fig. 30. — Recording Observations. 



between the solar-constant results and the temperatures of Argentina 

 and he is quite enthusiastic as to the probability that the forecasting 

 of the weather in Argentina will be materially improved by the aid of 

 solar-radiation measurements. If this proves to be the case, it is 

 greatly to be hoped that means will be found to increase the number 

 of observing stations qualified to measure solar radiation. The sta- 

 tion occupied in Chile lies on the Loa River, also on the railroad from 

 Antofagasta to Bolivia, about 150 miles east of Antofagasta. The 

 altitude is 7,500 feet and the conditions about the station are entirely 

 desert conditions, except in so far as modified by irrigation from the 

 Loa River. The station occupied is a disused mining property of the 

 Chile Exploration Company, which very generously allows its use 

 for the purpose of the solar work. Every effort is being made to 



