Oct. 27, 1882.] 



KNOWLEDGE • 



359 



THE NEW PRIXCETOX TELESCOL'E. 



THE accompanying engraving shows the great telescope 

 of the College of New Jersey, as it stands in Halsted 

 Observatory at Princeton. It ranks fourth in the list of 

 great refractors in use, and is by far the largest belonging 

 to any collegiate institution. 



Halsted Observatory was built some fourteen years ago, 

 at a cost of about $50,000. In making the alterations 

 necessary for the reception of the new telescope some 

 $5,000 more have been expended. The telescope and its 

 accessories cost S2G,000. This sum was contributed by the 

 friends of the college ; the largest donors being Robert 

 Bonner, Esq., and R. L. Stuart, Esq., who gave respectively 

 §10,000 and $G,000. 



Ihr t. 1, <,op.> was made by Alvan Cl.ark A Sons, of 

 Canibridgcport, Mass.; and all the appointments of the 

 Observatory are of the most modern character. The irox 

 dome under which the telescope is mounted is 39 feet in 

 diameter. The apparatus for turning the dome and 

 opening the shutter is driven by a four-horse power gas- 

 engine, which also actuates a small (Edison) dynamo- 

 machine for operating the electric lamps used in illunit- 

 nating the building and furnishing electric currents for 

 various spectroscopic purposes. 



The following data, respecting the telescope have been 

 kindiv furnished by Professor C. A. Young :— 



The diameter of the object-glass is 23 inches. The 

 radius of the curvature of the crown glass lens, outsido 

 surface, is 205-8 inches ; inner surface, 811) inches. The«e 



