182 PHOTOGRAPHY TN ASTRONOMICAL RESEARCH. 



uriiio: them, and wo are already face to face Avith the question whether 

 this is a desirable arrangement. Let me give a concrete example of 

 this modern situation. In the winter of 1900-1001 the small planet 

 Eros offered a si^ecially favorable opportunity for determining tlie 

 solar parallax, and some thousands of i)liotographs were taken at a 

 number of observatories for the puri)()se. It is not yet very clear 

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

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

 manner: but a small portion of it has l)een discussed by Mr. A. R. 

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

 by him in a recently jmblished paper (Mon. Not. R. A. S., June, 1004:) 

 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 nearly 

 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 two conclusions : Firstly, that it 

 is eminently desirable that these beautiful pictures 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 workers. 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- 

 equipped observatories and those less fortunate, but it is not at all 

 clear what direction that readjustment should take. One possibility 

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

 photographs was not conducted at the Lick ObserA'atory, but at Cam- 

 bridge. The price paid for the fine climate of Mount Hamilton is 

 the accumulation of work beyond the powers of the staff to deal with, 

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

 climates and equipment to take the photographs 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 numy photographs already taken, 

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

 similar to his own, where no observatory is in existence. If in such 

 cases the investigator will set up a measuring machine instead of a 

 telescope, he will deserve the gratitude of the astronomical world. 



But the case is not so clear when a telescope is already in exist- 

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

 some self-denial on his part to give up observing for a tinu> in oi-der 

 to discuss the Lick photographs 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 must certainly be exercised, 



