ADVISORY committee; on astronomy 97 



by the late Professor Keeler constituted a remarkable advance upon 

 all previous accomplishment in this line. This advance has been 

 still further signalized (according to the hearty, concurrent testi- 

 mony of a very large number of specialists and leading astronomers) 

 through the recent wonderful photographs of the nebula surround- 

 ing the new star in Perseus, and of other nebulae, obtained by the 

 aid of a two-foot reflector constructed and manipulated by Mr. 

 Ritchej', of the Yerkes Observatory, under the superintendence of 

 Professor Hale. In the latter case there is no doubt that the remark- 

 able results achieved were due not only to the excellence of the 

 two-foot mirror itself, but also in no slight degree to the perfection 

 of the mounting devised at the Yerkes Observatory. Indeed, it 

 appears probable that a five-foot reflector could be constructed 

 which would permit of the examination of the spectra of the bright- 

 est stars under a dispersion nearly or quite equal to that which is 

 ordinarily emplo5^ed in spectroscopic researches upon the Sun, and 

 under conditions as to the use of the spectroscope itself more favor- 

 able than has ever before been enjoyed in this class of researches. 

 "We believe that if a large reflector constructed on the general plan 

 devised at the Yerkes Observatory could be used at a carefully 

 selected station at some elevated point in southern California, or at 

 some place offering equal advantages in atmospheric conditions, it 

 would be possible to surpass all which has been accomplished 

 hitherto in the photography of nebulae, in the measurement of mo- 

 tions in the line of sight of the fainter stars, in the precise spectros- 

 copy of tj^pical stars, and in the measurement of heat emanating 

 from the stars. All of the researches would be of the most vital 

 consequence to the progress of astronomy in the lines in which the 

 astrophysical branch of that science is now tending ; and should the 

 means become available, we believe that the prospect of success in 

 the direction indicated would be well worthy of the attempt. In a 

 general way we estimate that the installation of such a plant might 

 cost from $100,000 to $150,000, and that it could be maintained in 

 efl&cient operation by the expenditure of from $10,000 to $20,000 

 per year, according to extent of operations. 



Need for Larger Resources in Astronomy. 



We have presented these three illustrations of attempts which it 

 is ideally desirable to make in an effort to secure, in each instance, 

 a unique and remarkable advance in astronomical research. They 



