8 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1911. 
cating long occupancy, a good knowledge of the people of Peru from the earliest 
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. 
Hrdlitka 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. 
