The Three Secretaries 211 



these fixed in his thought that he was able to explain them 

 even to those entirely unfamiliar with the subject. Notwith- 

 standing this freedom from ambiguity so characteristic of all 

 his statements, scarcely any of the conclusions of the past 

 twenty-five years have been called in question, or given occa- 

 sion for general criticism or debate. These characteristics, it 

 may safely be said, he brought with him to his work, as a 

 part of his equipment. His publications of 1874 exhibited 

 these as fully as do those of 1896; yet at the age of sixty- 

 two he retains them all. " His eye is not dim nor his natural 

 force abated." 



IV. 



WHEN Mr. Langley went to Pittsburg in 1867, he found 

 there an observatory only in name. It consisted of a build- 

 ing in which was mounted an equatorial telescope of thirteen 

 inches aperture, bought by the university from a local club of 

 amateur astronomers. Besides this, there was no apparatus 

 whatever, not even a clock, and the equatorial itself was with- 

 out the necessary accessories. There was neither library nor 

 endowment, and the director of the observatory was at liberty 

 to carry on original investigations only when this could be 

 done without neglecting his duties as instructor in the 

 college. 



Before beginning his work as an astronomer, it was 

 imperatively necessary that he should find some means 

 by which this work could be carried on, and to secure an 

 income to provide for the instrumental expenses of the 

 establishment, his object in going to Pittsburg having been, 

 not primarily to teach, but to secure opportunity for original 

 investigation. 



From the poverty of the Allegheny Observatory came 



