182 PHOTOGRAPHY IN ASTRONOMICAL RESEARCH. 



iiriiig- them, and we are already fac(> to face with the question whether 

 this is a desirable arranoenient. I^et me give a concrete example of 

 this modern situation. In the winter of 1900-1901 the small planet 

 Eros otFered a specially favorable opportunity for determining the 

 solar parallax, and some thousands of photographs were taken at a 

 nunil)er of observatories for the purpose. It is not yet very clear 

 how a definitive result will be obtained from the mass of material 

 accumulated, most of which is being dealt with in a very leisurely 

 maimer; but a snuill portion of it has been discussed by Mr. A. R. 

 Hinks, of Cambridge, and one of the many important results obtained 

 by him in a recently published paper (IVIon. Not. R. A. S., June, 1904) 

 is this: That the plates taken at the Lick Observatory are susceptible 

 of such accurate measurement, and so numerous, that a determination 

 of the solar parallax from them alone would have a weight neai-ly 

 equal to that from the whole mass of material. If the Lick plates can 

 be measured and reduced, it will not much matter if all the others are 

 destroyed. Whence we may deduce Iavo conclusions: Firstly, that it 

 is eminently desirable that these beautiful ])ictures should be meas- 

 ured and reduced as soon as possible; secondly, that we nnist consider 

 future plans of campaign very carefully if we are to avoid waste of 

 work and discouragement of workiM's. It is tolerably easy to reach 

 the first precise conclusion. I wish it were easier to arrive at some- 

 thing more definite in regard to the second. It seems clear that we 

 may expect some readjustment of the relations between the better- 

 equii)])ed obsei-vatories and those less fortunate, but it is not at all 

 clear what directioii that readjustment should take. One possibility 

 is indicated by the instance before us. The discussion of the Lick 

 })hotographs was not conducted at the Lick Observatory, but at 0am- 

 l)ridge. The i)rice paid for the fine climate of Mount Hamilton is 

 the accunndation of work beyond the ])()wers of the staif to deal with, 

 and the new division of labor may be for the observatories with fine 

 clinuites and equipment to take the photograi)hs and astronomers 

 elsewhere to measure and discuss them. Professor Kapteyn has set 

 us a noble and well-known example in this direction, and in view 

 of the pressing need for a study of many photographs already taken, 

 it is to be hoped that his exanijde will be followed, especially in cases 

 similar to his own. where no observatory is in existence. If in su(;h 

 cases the investigator will set up a m(>asuring machine instead of a 

 telescope, he will deserve the gi-ati(ude of (he astronomical world. 



But the case is not so clear when a (e]('sc()})e is already in exist- 

 ence. Mr. Hinks had a fine telescope at Oambridge, and it required 

 some self-denial on his pai't to gi\(' up ()l)S(M-\ing for a time in order 

 to discuss the Lick ph()togra[)hs and others. If the accumulations 

 already made, and others certain to be made in the future, are to be 

 dealt with, this kind of self-denial )uust certainly be exercised, 



