THE SMITHSONIAN INSTITUTION. 101 



THE IXTERXATIONAL EXCHANGES. 



A system of International Exchanges was begun in 1850 for tlie 

 free interchange of scientific publications betAveen institutions and 

 investigators in the United States and those in foreign lands. In 1867 

 Congress assigned to the Institution the duty of exchanging 50 copies 

 of all public documents of this country for similar documents of for- 

 eign nations, and this number was in 1901 increased to 100 sets at the 

 option of the Librarian of Congress. In 1889 a definite treaty, made 

 previously at a convention at Brussels, was formally proclaimed 

 by the President of the United States, wherein the United States 

 Government with a number of others undertook the continuation 

 of the exchange service on a more extensive basis. Out of this has 

 grown the Bureau of International Exchanges, for the maintenance 

 of which Congress provides by annual appropriation. The total 

 number of correspondents benefited by this service is 56,31-1, and 

 from 1850 to 1906, 2,748,852 packages were handled by it. The 

 Exchange service is in charge of an Assistant Secretary, Cyrus Adler. 



THE BUREAU OF AMERICAN ETHNOLOGY. 



The Bureau of American p]thnology is an outgrowth of researches 

 beginning early in the history of the Institution, which has, from 

 the outset, devoted much attention to the study of the tribes of 

 American Indians. It took its present form through Congressional 

 appropriation in 1879, and has collected a large amount of data 

 relating to the habits and customs, the laws, the religions, the lan- 

 guages, and the physical characteristics of the aborigines of this 

 continent. It has published 25 reports and 31 bulletins, and has 

 a great amount of unpublished material, including hundreds of 

 vocabularies. Besides doing a considerable amount of archeological 

 work, it has made important additions to knowledge, and also 

 invaluable collections. The Director of the Bureau of American 

 Ethnology, from its inception to 1902. was Alaj. J. AV. Powell, who 

 has been succeeded as chief l)y W. IT. Holmes. 



ASTROPHYSICAL OBSERVATORY. 



The Astrophysical Observatory was established in 1890 and has 

 been under the immediate direction of Mr. S. P. Langley, who here 

 continued researches previously begun at the Allegheny Observatory. 

 These investigations of solar radiations made possible by Mr. Ijang- 

 ley's invention of the bolometer, have resulted in the production of a 

 complete map by an automatic and absolutely trustworthy process 

 which shows at the unknown region or invisible spectrum the lines 



