12 REPORT OF THE SECRETARY. 



bution to the general intelligence of mankind, to institute scientific 

 inquiry as to the natural history, geology, geography, ethnology, archae- 

 ology, and scientific utilities of any new possessions it may acquire. 

 These inquiries should be made coherently and without clashing on the 

 part of the various Government interests involved. 



During the present year investigations among the American Indians 

 have been conducted by the Bureau of Ethnology, and several collabo- 

 rators of the Institution have made natural-history explorations, the 

 details of which are given in the paragraphs devoted to the National 

 Museum. 



PUBLICATIONS.- 



Secretary Henry said " It is chiefly by the publications of the Institu- 

 tion that its fame is to be spread through the world, and the monument 

 most befitting the name of Smithson erected to his memory." From 

 the beginning of the Institution a considerable portion of its annual in- 

 come has been expended in publishing the Smithsonian Contributions 

 to Knowledge and the Smithsonian Miscellaneous Collections. Through 

 these series, supplemented by the Annual Reports printed at the direct 

 expense of the Government, and the publications of the National 

 Museum, the Bureau of Ethnology, and the American Historical Asso- 

 ciation, issued under the direction of the Institution, nearly all branches 

 of human knowledge are represented in the works published during the 

 last fifty years, which form a library of nearly 250 volumes, beside sev- 

 eral hundred pamphlet reprints of the memoirs and articles contained 

 in the serial volumes. 



Contributions to Knowledge. — One new memoir of this series was pub- 

 lished during the year, the result of investigations by Drs. Lummer 

 and Pringsheim, of Charlottenburg, Germany, on the ratio of the 

 specific heats at constant pressure and at constant volume of air, 

 oxygen, carbon dioxide, and hydrogen. This research was aided by a 

 grant from the Hodgkins fund of the Smithsonian Institution. After 

 a period of notable advance the kinetic theory of gases seems to have 

 fallen into temporary abeyance, possibly from a fundamentally imper- 

 fect understanding of their behavior. Progress in the knowledge of 

 this fundamental nature of gases may reasonably be looked for from 

 interpretative researches on their thermal capacity, and this paper may 

 be considered as a step in this direction. Aside from its exceptional 

 importance in thermodynamics, the heat ratio is of interest as affording 

 a clue to the character of the molecule, and Drs. Lummer and Prings- 

 heim, using a new method, appear to have for the first time reached 

 coincident results on the incoercible gases examined. 



The original edition of the Secretary's memoir on The Internal Work 

 of the Wind, published in 1893, having become exhausted, some addi- 

 tional copies have been printed from the stereotype plates, in which a 

 few minor changes have been made. 



