Longihiile of Meiv-York. 143 



Art. XIX. — Longitvdc of J^ew-Yo7'k ascertained by he ob- 



servations o/'Prof. James Renwick. 



t 



Columbia College, New-York, Feb. 25th, 1822. 



TO PROF. SILLIMAN. 



Sir, 



J 



I beg leave to commuicate, for publication in your valua- 

 ble journal, my observation of tbe Solar Eclipse of 27th 

 August Jast. 



The observation was made from the cupola of the Col- 

 lege in latitude 40° 42/ 45", N, as deduced from a number 

 of observations made by my colleague Dr. Adrain. 



The instruments made use of were an Achromatic Teles- 

 cope by Dollond of four feet focal distance, a box-chro- 

 nometer by Wingham, (London) and a pocket-chronom- 

 eter by Morrice, (London.) The rates of both time keep- 

 ers had been carefully noted for some time previous, and 

 their error was observed by means of transits of the sun on 

 the preceding and following day* This part of the prepa- 

 ration was performed by Messrs. T. Sf B. Demilt, watch 

 makers of this city, who have erected an observatory and 

 provided themselves with a transit and an excellent astro- 

 nomical clock. 



With these instruments the times of beginning and end, 

 were as follows, viz. 



days. hrs. 



Beginning — x\pparent time af New-York. 



1821. August. - - - 26.19.37'.32" 

 End do. do. do. do. 26.22.20'.58" 



The morning was by no means favorable, I was in conse- 

 quence prevented from taking a set of altitudes, that might 

 bave enabled me to state the time from ray own observations. 



The view of the beginning of the Eclipse was as favoura- 

 ble as I could have desired, the clouds cleared for a few 

 niinutes from the sun's face, and my preparatory projection 

 was so far accurate as to enable me to have in the centre of 

 the field of the telescope the exact point of impact. 



With regard to the end, the clouds had by that time ac- 

 cumulated to such a degree as to compel me to remove the 



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