REPORT OP THE SECRETARY. 11 



to Knowledge, in quarto, and Smithsonian Miscellaneous Collections, 

 in octavo form. The editions of these series are necessarily limited 

 in number for distribution almost entirely to a carefully selected 

 list of libraries throughout the world, where they may be readily 

 consulted by students and investigators. There is also issued, at the 

 cost of Government appropriations, an annual report, in the general 

 appendix of which is included a considerable number of papers, 

 either original or selected from more or less inaccessible sources, 

 reviewing the progress and present condition of the natural and 

 physical sciences and other branches of human knowledge. Al- 

 though the edition of the report is considerable, yet the supply is 

 each year exhausted within a very short time after its publication. 



Contributions to Knowledge. — The Langley Memoir on Mechanical 

 Flight, referred to in my last report, had been put to press and was 

 nearly ready for distribution at the close of the fiscal year. This 

 work forms a quarto volume of over 300 pages and a hundred plates. 

 The memoir was in preparation at the time of Mr. Langley's death 

 in 1906 and part of it had been written by him, bringing the work 

 down to May, 1896, the date of his demonstration that a machine 

 heavier than air could be made to fly under its own power. The 

 account of later experiments, from 1897 to 1903, was written by Mr. 

 Charles M. Manly, who became Mr. Langley's chief assistant in 1898. 



Miscellaneous Collections. — Twenty papers on various subjects have 

 been added to the series of Smithsonian Miscellaneous Collections, 

 including descriptions of a number of new species of animals ob- 

 tained by the Smithsonian African expedition and the biological 

 survey of the Panama Canal Zone, and several papers, mentioned 

 elsewhere, giving some results of my studies and field work in 

 Cambrian geology and paleontology, besides an interesting paper 

 by Dr. Hrdlicka on his anthropological investigations in Peru. 



Smithsonian Tables. — In connection with the system of meteoro- 

 logical observations established by the Smithsonian Institution about 

 1850, a series of meteorological tables was compiled by Dr. Arnold 

 Guyot at the request of Secretary Henry, and the first edition was 

 published in 1852. Though primarily designed for meteorological 

 observers reporting to the Smithsonian Institution, the tables were 

 so widely used by physicists that it seemed desirable to recast the 

 entire work. It was decided to publish three separate sets of tables, 

 each containing the latest knowledge in the field which it covered, 

 but together forming a homogeneous series. The first of the new 

 series, Meteorological Tables, was published in 1893; the second, 

 Geographical Tables, in 1894; and the third, Physical Tables, in 

 1896. In 1909 another volume was added, so that the series now 

 comprises: (a) Smithsonian Meteorological Tables, (b) Smithsonian 

 Geographical Tables, (c) Smithsonian Physical Tables, and (d) 



