io6 THE POPULAR SCIENCE MONTHLY 



distances and grandeur of the problems of astronomy, and the very 

 remoteness and difficulty of studying the stars attract him. 



My object in calling your attention to this matter is the hope that 

 what I have to say of the organization of astronomy may prove of use 

 to those interested in other branches of science, and that it may lead to 

 placing them on the footing they should hold. My arguments apply 

 with almost equal force to physics, to chemistry, and in fact to almost 

 every branch of physical or natural science, in which knowledge may be 

 advanced by observation or experiment. 



The practical value of astronomy in the past is easily established. 

 Without it, international commerce on a large scale would have been 

 impossible. "Without the aid of astronomy, accurate boundaries of 

 large tracts of land could not have been defined and standard time 

 would have been impossible. The work of the early astronomers was 

 eminently practical, and appealed at once to every one. This work has 

 now been finished. We can compute the positions of the stars for years, 

 almost for centuries, with all the accuracy needed for navigation, for 

 determining time or for approximate boundaries of countries. The 

 investigations now in progress at the greatest observatories have little, 

 if any, value in dollars and cents. They appeal, however, to the far 

 higher sense, the desire of the intellectual human being to determine 

 the laws of nature, the construction of the material universe, and the 

 properties of the heavenly bodies of which those known to exist far out- 

 number those that can be seen. 



Three great advances have been made in astronomy. First, the 

 invention of the telescope, with which we commonly associate the name 

 of Galileo, from the wonderful results he obtained with it. At that 

 time there was practically no science in America, and for more than 

 two centuries we failed to add materially to this invention. Half a 

 century ago the genius of the members of one family, Alvan Clark and 

 his two sons, placed America in the front rank not only in the con- 

 struction, but in the possession, of the largest and most perfect tele- 

 scopes ever made. It is not easy to secure the world's record in any 

 subject. The Clarks constructed successively, the 18-inch lens for 

 Chicago, the 26-inch for Washington, the 30-inch for Pulkowa, the 

 36-inch for Lick and the 40-inch for Yerkes. Each in turn was the 

 largest yet made, and each time the Clarks were called upon to surpass 

 the world's record, which they themselves had already established. 

 Have we at length reached the limit in size ? If we include reflectors, 

 no, since we have mirrors of 60 inches aperture at Mt. Wilson and 

 Cambridge, and a still larger one of 100 inches has been undertaken. 

 It is more than doubtful, however, whether a further increase in size 

 is a great advantage. Much more depends on other conditions, espe- 

 cially those of climate, the kind of work to be done and, more tban all, 



