196 ON THE OBLIQUITY 



PARTICULARS OF OBSERVATIONS. 



13. I stated above, that from want of sufficient knowledge of my 

 instrument, I had been under the necessity of rejecting the solsticial ob- 

 servations, which I had taken in December, 1808, and June, 1809; these 

 receding rather too wide, for deducing from them the obliquity of the 

 ecliptic. It was only in December following that I obtained sufficient 

 checks over the irregularities I have noticed, for relying on the powers 

 of rny instrument. But then the weather proved generally unfavorable, 

 and I obtained but a few unobjectionable observations, two of which 

 only, were sufficiently near the solstice, for the present purpose, and oa 

 which alone I would not have trusted the fate of the present paper, 

 though the mean result agrees within 2 of all subsequent setts. 



14. Observations of the sun's altitude in December, 1809. 



20th. 23d. 



Obs'd Altitude of O's Lower Limb, . . 53 13 14.88 53 12 38.30 



Refraction, — 35.30 — 35.50 



53 12 39.58 53 12 2.80 



Parallax, ...... r ... ...,--,--..... f 5.12 + 5,12 



53 12 44.70 53 12 7.92 



©VSemidiameter, .....--..._.--.« '+ 16 17.40 + 16 17.60 



Cor'd. Altitude O 's Center, ......... 53 29 2. 10 53 28 25.52 



90 90 



Zenith Distance, .._:.. r -. .,.;., - .'.. V. . 36 30 57.90 36 31 34.48 



The sun entered y? onthe 21st of December, at 16 38, to which instant 

 the above zenith distances are to be reduced, by interpolating for the 

 maximum of the declinations, given in the ephemerides for the 19th, 

 ^oth, g.i st and 22d, and comparing this quantity* with the declination 



■■— - ■ — - ■ ■ - ■ ■■ - — - ■ ■ ■ ■ ■-- ■ -■■--■ -• — j 



* Maximum of Decimation on 21st, 23 27 4,3.136 23 27 43.136 



Declination on 20th, ................ = 23 26 50.600 -23 27 26.640 



Differences,. „......„.. .„..„.- 52.536 16.496 



