Septembee 7, 1900.] 



SCIENCE. 



355 



Eesearch and the Relation of Astrophysics 

 to other Physical Sciences.' In the spring 

 of 1898 he had practically decided to ac- 

 cept a position on the staff of the Yerkes 

 Observatory, and would have done so had 

 he not just then been appointed Director 

 of the Lick Observatory. Strenuous efforts 

 were made by the citizens of Allegheny to 

 retain him, and a project for a new Alle- 

 gheny Observatory was set on foot by Dr. 

 J. A. Brashear, who has since carried it to 

 a successful conclusion, though at the time 

 in question it was impossible to raise the 

 necessary funds. At the Yerkes Observa- 

 tory our regret in losing so able and genial 

 a coadjutor was tempered by the feeling 

 that the cause of science would undoubtedly 

 be best advanced by placing such a man in 

 charge of the great institution on Mt. Ham- 

 ilton. 



This view has been most amply justified 

 by the recent work of the Lick Observatory, 

 which has attained the highest degree of 

 eflSciency under Keeler's administration. 

 The activity of the Observatory in various 

 fields of research, and the uniform excel- 

 lence of observations made by men work- 

 ing under the inspiration of able leader- 

 ship, have been recognized by all who keep 

 in touch with astronomical progress. 



But Keeler's recent work on Mt. Hamil- 

 ton has not been confined to the direction of 

 the affairs of a great observatory. The re- 

 markable success of his experiments with 

 the Crossley reflector, of which a full ac- 

 count is fortunately preserved in the June 

 number of the Astrophysieal Journal, has im- 

 pressed everyone who has seen the wonder- 

 ful photographs of nebulte and star clusters 

 made with this instrument. The. record of 

 this work, like that of many other events 

 in Keeler's career, is full of instruction to 

 those who aspire to achieve success as inves- 

 tigators. When entering upon his duties 

 at Mt. Hamilton, Keeler called together the 

 members of the staff to confer upon the obser- 



vations to be undertaken. It is customary to 

 divide the nights of the week with the great 

 telescope among several observers, each of 

 whom is pursuing a certain class of observa- 

 tions. When the division had been com- 

 pleted it was remarked with surprise — for 

 the privilege of using such a telescope is 

 highly valued — that Keeler had taken no 

 nights for himself. On the contrary, in- 

 stead of benefiting by the advantages which 

 must have resulted from the use of the 

 powerful and perfect refractor, he had 

 chosen the difficult and rather uninviting 

 task of bringing into use the Crossley re- 

 flector, an instrument of great optical power, 

 but provided with a mounting of such de- 

 sign and construction as to render it almost 

 unfit for exacting work. Although trans- 

 ferred from England to Mt. Hamilton sev- 

 eral years before, no results had been ob- 

 tained with this telescope in its new location. 

 The reflector was best adapted optically for 

 the photography of faint nebulae, but me- 

 chanically it was not adequate for such 

 work which more than any other demands a 

 mounting of the highest stability and per- 

 fection of detail. The story of how obstacle 

 after obstacle was encountered and over- 

 come is modestly told in the paper to which 

 reference has been made. The resulting 

 photographs of nebulae far surpass any sim- 

 ilar photographs ever before obtained, and 

 reveal new and unexpected features of 

 the first importance. Hundreds of hith- 

 erto unknown nebulae were discovered 

 on the plates, and from an examination 

 of these a fact of great significance was 

 established, viz : that the majority of the 

 nebulae are spiral in form. It has long 

 been known that certain of these cloud- like 

 masses, from which the stars are supposed 

 to be formed, show a spiral structure, but 

 these were considered to be exceptions, and 

 by no means type objects. As the result of 

 Keeler's work it does not appear improbable 

 that future theories of stellar evolution will 



