October 4, 1912] 



SCIENCE 



423 



Statistical investigations concerning all 

 four of these classes of bodies have recently 

 been made; they constitute additions of 

 the most desirable kind to our stock of 

 knowledge, and have done much to indi- 

 cate in what directions further additions 

 are to be sought. Apart from all this, if 

 the discovery of a comet (for example) 

 were not otherwise useful, it would fre- 

 quently justify itself by calling attention 

 to men of promise. It was in this way 

 that the astronomical world has come to 

 have the benefit of the extraordinary tal- 

 ents of Edward Emerson Barnard. With 

 a little telescope purchased out of the 

 meager earnings of his youth, he discov- 

 ered in rapid succession a surprising num- 

 ber of faint comets. The attention thus 

 attracted to him soon resulted in an ap- 

 pointment at the Lick Observatory, and 

 later one at the Yerkes Observatory, so 

 that he has had access to some of the most 

 pow;erful instruments in the world. He 

 has used these instruments to excellent 

 purpose and with a diligence that has 

 rarely been equalled; but it is significant 

 that in the past twenty years he has made 

 no further discoveries. In a case like this 

 it would be more to the point to speak of 

 the comet as having discovered the man, 

 than of the man as having discovered the 

 comet. 



We are often told that an astronomer 

 pointing his telescope more or less at ran- 

 dom to the sky and faithfully recording 

 what he sees or photographs, is bound to 

 add something to our fund of knowledge. 

 While this is true, promiscuous observing 

 is to be encouraged only if nothing else is 

 possible, and is surely never to be encour- 

 aged within an observatory. The fact is 

 that astronomy of to-day demands answers 

 to definite questions; the astronomer who 

 goes to his telescope without having one of 

 these questions in mind is at least partially 



wasting his time. In other words an ob- 

 servatory staff should regard their profes- 

 sion as a branch of engineering, in which 

 the problems to be solved are quite as defi- 

 nite as those, for example, that confront 

 the civil engineer. If this seems to you to 

 be a somewhat dry view to take of so 

 beautiful a subject as astronomy, I would 

 remind you that none save engineers are 

 especially interested in the plans and speci- 

 fications for a bridge, but that all of us can 

 take delight in the finished structure, either 

 for its utility or its beauty. In the same 

 way the methods employed by the astron- 

 omer are almost always of very special in- 

 terest, while the results of his work appeal 

 to us all as educated men and women. 

 How long will the sun continue to be sen- 

 sibly as bright and as hot as it is now? 

 How does our sun compare in size and 

 glory with other stars ? How comes it that 

 some stars are double, while others (our 

 sun among them) are single? How are 

 the stars distributed in space? What 

 causes some stars to vary in brightness? 

 These are some of the questions to which 

 astronomers are seeking the answers, and 

 the results of these inquiries will surely 

 interest you as deeply as they do the as- 

 tronomer himself. 



Let me now state briefly what specific 

 use we intend to make of our various in- 

 struments. Under the north dome is the 

 Keeler memorial reflector, having an aper- 

 ture of thirty inches. This telescope and 

 the Mellon spectroscope attached to it have 

 been in constant use during the past six 

 years in the prosecution of a single re- 

 search, the determination of the orbits of 

 spectroscopic binaries. This work we shall 

 continue as long as it remains profitable to 

 do so. Under the same dome is a vertical 

 or tower telescope of nine inches aperture 

 and twenty-nine feet focal length. This is 

 ' ' fed " by a coelostat mirror on the mount- 



