REPORT OF THE SECRETARY. 15 



necessary expenses of members of the committee in going to, returning from, 

 and while attending, meetings of the committee : Provided, That an annual 

 report to the Congress shall be submitted through the President, including an 

 itemized statement of expenditures. 



On July 27, 1914, the Institution published a report by Dr. Zahm 

 on European aeronautical laboratories, in which he describes the 

 buildings, equipment, and operations of laboratories in England, 

 France, and Germany. 



Although, as above stated, it was not practical to continue the 

 advisory committee of 1913 as originally planned, nevertheless the 

 individual members of the committee have been active in their in- 

 vestigations, and several valuable reports have been received, some 

 of which are as yet confidential or incomplete, one of those being a 

 report on wireless communications to and from air craft. 



Mr. Buckingham completed and published a masterly paper on the 

 mathematical principle governing the relations of experimental mod- 

 els of all sorts to those of full-scale machines. Dr. Humphreys pub- 

 lished a long paper on the Physics of the Atmosphere. Dr. Zahm 

 helped to design for the United States Army a 200-horsepower bi- 

 plane, and published a mathematical method of analyzing the stresses 

 sustained by such an aeroplane during flight. 



At the annual meeting of the Regents on December 10, 1914, Dr. 

 Alexander Graham Bell, Senator William J. Stone, Representative 

 Ernest W. Roberts, Mr. John B. Henderson, jr., and Secretary Wal- 

 cott were appointed a committee to consider questions relative to the 

 Langley Aerodynamical Laboratory. 



PUBLICATIONS. 



The publications of the Smithsonian Institution and its branches 

 during the year comprised a total of 6,753 printed pages, accom- 

 panied by 655 plates of illustrations, and the number of copies dis- 

 tributed of these various j)ublications, both pamphlets and bound 

 volumes, aggregated 132,010. 



The Institution has for one of its primary objects the " diffusion 

 of knowledge," and this aim is carried out by printing and distribu- 

 ting the results of scientific investigations, accounts of explorations 

 and researches, of progress in the various branches of science, and of 

 development in any phase of human endeavor which would tend to 

 increase "knowledge among men." Of its three series of publica- 

 tions, the Contributions to Knowledge, Miscellaneous Collections, 

 and the annual reports, the first two are issued in limited editions 

 at the expense of the Institution and are sent out to libraries, institu- 

 tions, and interested individuals throughout the world. The annual 

 reports, containing in addition to the administrative reports a gen- 

 eral appendix of original and selected papers showing the recent 

 progress made in all branches of natural and applied science, are 



