8 AXXI'AL REPOKT SMITHSONIAN INSTITUTION, 1911. 



eating long occupancy, a good knowledge of the people of Peru from the enrliest 

 times is very desirable, and would constitute a solid basis from which it 

 would be relatively easy to extend anthropological comparison to all the rest 

 of the native peoples of the southern continent. Such anthropological com- 

 parisons will be greatly facilitated by the collections acquired on this expedition. 



Some of the interesting results of his work are described by Dr. 

 Hrdlicka in a pamphlet recently published by the Institution. 



RESEARCHES UNDER THE HODGKINS FUND. 



With a view to aiding in the establishment of an international 

 scale for the measurement of solar radiation, as mentioned in my 

 last report, a limited grant from the Hodgkins fund has been 

 approved for the construction, in the Smithsonian workshops, of 

 several silver disk pyrheliometers, after the design of Mr. C. G. 

 Abbot, Director of the Smithsonian Astrophysical Observatory. 



The International Solar Union has for some time been inter- 

 ested in the establishment of an international standard scale of 

 radiation, and pyrheliometers of varying types have been in use 

 at different observatories. The desire, however, for still another 

 simple but accurate instrument seemed general, and the Institution 

 has been gratified to learn that, by the use of the Abbot pyrheli- 

 ometer, a more exact knowledge of solar radiation and the influence 

 of the terrestrial atmosphere upon it have been promoted. 



Arrangements have been made whereby the Abbot pyrheliometer 

 is now in use in widely separated localities. There is one in the 

 astronomical observatory established by Harvard College at Are- 

 quipa, Peru; another in the observatory at Teneriffe: and two have 

 been sent to the minister of agriculture in Buenos Aires for meteoro- 

 logical stations in Argentina. The Department of Agriculture, the 

 Bureau of Standards, and the United States Weather Bureau in 

 Washington are supplied with the instruments; Prof. Chistoni, of 

 the Royal University of Naples, has installed one there, and the 

 Imperial College of Science and Technology at South Kensington, 

 London, has secured one. Prof. Violle, of the National Observatory 

 of Arts and Crafts, Paris, was among the first to install one of the 

 Abbot instruments, and one has been sent to Dr. Hellmann, director 

 of the Royal Prussian Meteorological Institute, Berlin. The Uni- 

 versity of Toronto, Canada, the University of Wisconsin, and the 

 Central Physical Observatory of St. Petersburg also have them, and 

 inquiries from other institutions as to the mode of securing them 

 are frequent, so that the establishment of the desired international 

 standard of estimating and recording the variations of solar radia- 

 tion seems to have been already aided by the use of uniform instru- 

 ments in many widely separated localities. 



