CONTENTS 



Page 



List of officials v 



Outstanding events 1 



Summary of the year's activities of the branches of the Institution 2 



The establishment 5 



The Board of Regents 5 



Finances 7 



Matters of general interest 7 



Andrew W. Mellon's art gift to the Nation 7 



Proposed Smithsonian Gallery of Art 17 



Smithsonian radio program 18 



Walter Rathbone Bacon Traveling Scholarship 21 



Sixth Arthur lecture 22 



Explorations and field work 22 



Publications 23 



Library 24 



Appendix 1. Report on the United States National Museum 25 



2. Report on the National Collection of Fine Arts 35 



3. Report on the Freer Gallery of Art 43 



4. Report on the Bureau of American Ethnology 49 



5. Report on the International Exchange Service 59 



6. Report on the National Zoological Park 69 



7. Report on the Astrophysical Observatory 99 



8. Report on the Division of Radiation and Organisms 103 



9. Report on the library 107 



10. Report on publications 113 



Report of the executive committee of the Board of Regents 119 



GENERAL APPENDIX 



Constitution of the stars, by Sir Arthur Stanley Eddington 131 



Discoveries from solar eclipse expeditions, by S. A. Mitchell 145 



Changes in the length of the day, by Ernest W. Brown 169 



The thunderstorm, by E. A. Evans and K. B, McEachron 177 



The electron: Its intellectual and social significance, by Karl T. Compton.. 205 



Photography by polarized light, by J. W, McFarlane 225 



Measuring geologic time: Its difficulties, by A. C. Lane 235 



The earth's interior, its nature and composition, by Leason H. Adams 255 



Origin of the Great Lakes basins, by Francis P. Shepard 269 



The biography of an ancient American lake, by Wilmot H. Bradley 279 



Our water supply, by Oscar E. Meinzer 291 



The first crossing of Antarctica, by Lincoln Ellsworth 307 



Moving photomicrography, by W. N. Kazeeff 323 



Fresh-water fishes and West^Indian zoogeography, by George S. Myers 339 



The breeding habits of salmon and trout, by Leonard P. Schultz 365 



What is entomology? by Lee A. Strong 377 



Maize — our heritage from the Indian, by J, H. Kempton 385 



V 



