32 



Princeton, July 25, 1848. 



My Dear Sir, — I had intended ere this to have sent to the Ameri- 

 can Philosophical Society, a minute of the observations made by Dr. 

 Philip Ten Eyck, Professor in the Albany Academy, and myself, on 

 the small eclipse of the sun, which occurred in March last. 



The place of observation was a few rods N. E. of the Albany 

 Academy, the position of which, according to the table in the Ameri- 

 can Almanac, is in Lat. 42° 39' 3" N., Longitude 73° 44' 49" W. 

 of Greenwich. 



The weather both before and after the eclipse was very change- 

 able, and we, consequently, contented ourselves with an imperfect 

 observation of the sun's transit on the day before, applying, after- 

 ward, corrections for rate, by a comparison of the patent lever watch, 

 which we used, with a clock furnished with a compensation pendu- 

 lum. These observations and reductions were made by Dr. Ten 

 Eyck. 



The beginning was lost by my having inadvertently taken the 

 angle with the north pole for the angle with the vertical. 



Indentation first perceived (in a small telescope) by Dr. Ten 

 Eyck, at — 



7h 37m 42s. 4 mean time, civil reckoning. 

 8 4 5.4 indentation no longer certain. 



4 18.4 indentation had certainly disappeared. 



At 8h Im 46s.4, or about 2| minutes before the end, I perceived 

 an elevation or projection of the cusps beyond the natural outline of 

 the remainder of the sun's disc. I was led to conclude that it could 

 hardly be a mere optical deception, from the fact that it rather 

 seemed to increase as the moon's disc seemingly slipped off, or sepa- 

 rated from that of the sun, by a very oblique movement ; and the 

 same appearance was not noticed at a period equally near to the 

 beginning. 



The telescope which I used was from the manufactory of Uschnei- 

 der & Fraunhofer. Eye-piece adjusted for direct vision ; power 80,- 

 screen-glass red. 



The projections were, it may be, rather more conspicuous than in 

 the enclosed sketch, made after completing the observations, in which 

 1 was careful not to overrate the appearance. 



I remain, dear sir, yours, very truly, 



STEPHEN ALEXANDER. 



