THE lUyTOKY OF THE TELESCOPE.* 



!>y Piol". C. S. IlASTmGS, Yalv Uiiircr.sitij. 



Tlicie is no instiuuieiit wliicli has done so mn{;!i to widen the scope 

 of human knowledge, to extend our notions of tlic universe, and to stim- 

 uhite intelh'ctual activity as has the telescope, unless the microscope 

 be regarded as a successful rival. But even admitting a parity in 

 scientitic iin|)ortance, the former instrument is incomparably niorv 

 interesting in its history, in the same degree that its history is more 

 simple and more comprehensible. To trace its development from a 

 curious toy in the hands of its discoverer, for we shall see that this term 

 is more appropriate than inventor, to the middle of this century, is to 

 be brought into contact with most of the great philosophers, from the 

 tiiue of the Renaissance, who have achieved greatness in physical 

 science, Galileo, Torricelli, Huyghens, Cassiui, jSTewtoi], Halley, Kepler, 

 Euler, (yahiiault, the Herschels, father and son, Fraunhofer, Gauss — 

 from only a portion of the list of great names. Its growth toward per- 

 fection has constant 1\- carried with it increased [>recisi()n in the applied 

 sciences of navigation ami of all branches of engineering. It would be 

 easy to show that even pure matheniatics would be in a far less forward 

 state had there been no problems of astronomy and physics which were 

 tirst suggested by the emi)loyment of the telescope. It is to. this his- 

 tory that I venture to invite your attenti(m this evening. L purpose to 

 re\iew succinctly the origin and development of tliis potent aid in the 

 study of nature, to mmu' some of the more imi)ortant ac^hievemeuts de- 

 l)ending ui)on it, and to tra(;e its gradual improNcment to the nuigniti- 

 cent and coni])licated instrument which constitutes the modern eipia- 

 torial. After this sketch I shall tiy to give an ideai of the imperfections 

 which the conscientious artisan has to contend with in attaining per- 

 fection, and to make clear the methods which ha-\ e been employed in 

 reducing these imperfections in the noble instrument now erected at 

 this institution,! and ex])lain why its ])osse!4Sors are so hopeful of grat- 

 ifying success. 



* Addi-eas delivered at the dedication of tlio fJoodsell Observatory of Carleton 

 Cnll('<jje, Nortlifield, Minn.. June 11, 1891. (I'roni the Sidirral .Ucsseiif/er, August, 



1891, vol. X, pp. 3ar.-:!.-)i. > 



t Carleton Collcirf. 



95 



