180 PHOTOGRAPHY IN ASTRONOMICAL RESEARCH. 



loiigor necessar}^ to have copies of all. This applies, of course, to 

 other publications as well, and though we may take some time to 

 grow out of the sentimental desire for a complete library', and though 

 the existence of a few such complete institutions .may always be 

 desirable, I venture to think that manj^ observatories will ultimately 

 be driven to the plan of acquiring only what is certainly and imme- 

 diately useful, depending on temporary loans from central institu- 

 tions for other material. 



But there is a class of problems differing totally in character from 

 these practical questions of storage and preservation of plates. A. 

 period of suddenly increased activity such as we have been passing 

 through in astronomy is not without important effects on astronomers 

 themselves. The human element in our scientific work is sometimes 

 overlooked and generally accorded only a subordinate importance; 

 but, coming as I do from an old university devoted to the humanities, 

 I may be perhaps forgiven for calling attention to a few human con- 

 siderations. In the first place, I have felt some anxiet}^ lately for 

 that very important body of astront)mers who are sometimes called 

 " amateurs," though the name is open to criticism — those whose 

 opportunities for work are restricted to a more or less limited leisure. 

 it is a body which is somewhat sensitive to the feeling that astronom- 

 ical work has gone beyond them ; that in the presence of large instru- 

 ments and of the special knowledge acquired by those using them 

 their own efforts and their own humbler instruments are no longer of 

 any vahie. If I am right in supposing that this feeling has been 

 called into existence lately by the rapid advances made in photog- 

 raphy, it is certainly not for the first time. At [)revious epochs this 

 •liffidence has found expression, and has, I am glad to say, been met 

 by careful contradiction; but it is necessary to repeat the expostula- 

 tion again and again, for the anxiety is apt to crop up with every new 

 development of astronomical activity. 



The earlier days of photography Avere better ones than usual foi- 

 the amateur; indeed, the introduction of the photographic method 

 is largely due to the Avork of such men as Kutherfurd and Draper in 

 America, I)e la l\\w and Common in I^ngland. lUit iu)w that we have 

 passed beyond the stage when each new ])late taken was a revelation ; 

 now that Ave are tolerably familiar with, at any rate, the nuiin tyi>es 

 of possible pliotographs which can be taken Avith modest a2)[)aratiis; 

 more esj)ecially noAV that Ave have begun to discuss in elaborate detail 

 the measurement of star ])ositions or of stellar spectra, the old shyness 

 is beginning to crop up again. But it is of the utmost importance 

 that this shyness should be zealously overcome. Perhaps, after all, it 

 is not sufficient to assert that there is still good Avork for amateurs to 

 do, nor even to mention a fcAv instances of such Avork urgently re- 

 quired; perhaps it should be made easier for them to folloAV Avhat is 



