SECTION B ASTROPHYSICS 



(Hall 9, September 21, 3 p. w.) 



CHAIRMAN: PROFESSOR GEORGE E. HALE, Director of the Yerkes Observatory. 

 SPEAKERS: PROFESSOR HERBERT H. TURNER, F. R. S., University of Oxford. 

 PROFESSOR WILLIAM W. CAMPBELL, Director of the Lick Observa- 

 tory. 

 SECRETARY: MR. W. S. ADAMS, Yerkes Observatory. 



THE RELATIONS OF PHOTOGRAPHY TO ASTROPHYSICS 



BY HERBERT HALL TURNER 



[Herbert Hall Turner, D.Sc., F.R.S. , Savilian Professor of Astronomy: Director 

 of the University Observatory, University of Oxford, England, b. Leeds, 1861. 

 Leeds Modern School, 1870-74; Clifton College (Scholar), 1874-79; Trinity 

 College, Cambridge (Foundation Scholar), 1879-84. Chief Assistant, Royal 

 Observatory, Greenwich, 1884-94; Fellow of Trinity College, Cambridge, 

 1885-91; Savilian Professor of Astronomy and Fellow of New College, Ox- 

 ford, 1894 to present time. Secretary, Royal Astronomical Society, 1892-99; 

 President, 1903-05; Council of Royal Society, 1901-03; Chairman of Subsection 

 of Astronomy, British Association, 1901. Editor of The Observatory, 1888-97. 

 Author of Modern Astronomy, Astronomical Discovery.] 



THE European astronomers here present have to thank the organ- 

 izers of this Congress for much more than their hospitable invitation 

 to attend it, and the opportunities thus afforded of meeting here in 

 St. Louis so many men eminent in their own or other branches of 

 knowledge: over and above this they owe to them opportunities 

 of seeing the great observatories which have developed so rapidly in 

 this country during the last quarter of a century, and of admiring at 

 close view the resources and the work of which the fame had already 

 reached us across the Atlantic. This is not the time or the place for 

 any account of what we have seen and learned; but not to put on 

 record a word or two of appreciation of the great works accomplished, 

 and of that munificence on the part of American citizens which has 

 rendered them possible, would be indeed an omission. We from 

 Europe are, in at least one respect, critics well qualified to judge 

 whether an adequate return is being obtained for endowments such 

 as have recently fallen to the happy lot of American astronomers, 

 for most of us have had some practice in the use of such endow- 

 ments hypothetically . The constraints of more modest equipments 

 have inevitably suggested plans for work on a larger scale observ- 

 atories-in-the-air which our imaginations fill with beautiful and 

 novel apparatus, where the preliminary trials are always successful 



