6o8 The Smithsonian Institntion 



of the bibliography is given in pages 66 to 133, and is sub- 

 divided into 45 sections, as comets, stars, meteors, ecHpses, 

 etc. An author-index, pages 363 to 394, is an admirable 

 complement to the index by subjects. 



"The Bibliography of the Chemical Influence of Light," 

 by Doctor Tuckerman (22 octavo pages) should be men- 

 tioned among astronomical bibliographies, as it gives the 

 scientific bases of photography. 



An index to the literature of photography is (1891) in 

 preparation by the same author. The two works, taken to- 

 gether, will be of the greatest use in connection with the 

 application of the art of photography to astronomical re- 

 searches. 



SHORT PAPERS ON ASTRONOMICAL SUBJECTS 



In the early years of the Institution it was part of the plan to 

 provide for popular lectures on scientific subjects during the 

 sessions of Congress by distinguished specialists. 



Among these lectures we may mention six on the " Prog- 

 ress of Astronomy," by Doctor B. A. Gould, and one by Pro- 

 fessor S. Alexander, on the "Relations of Space and Time" 

 (both referred to, but not printed, in the Smithsonian Re- 

 port, 1854); one by Professor E. S, Snell, on "Planetary 

 Disturbances" (Smithsonian Report, 1855); and lectures 

 on "Astronomy," by Professor Alexis Caswell (Smithsonian 

 Report, 1858). 



The plan of regular lectures was not systematically main- 

 tained in subsequent years. They were replaced by pop- 

 ular papers on scientific topics, either original or transferred 

 from other periodicals. In looking over the Reports in the 

 Library of the Lick Observatory (not quite a complete set) 

 I have found the following references to papers of the sort. 

 This list may not be exhaustive : 



