ASTRONOMICAL AND GEODETIC OBSERVATIONS. 



13 



Observations for time, November 29tb, 18G0. 

 Double altitudes of a Lyrte, with reflecting circle. 



T T C+32' 40" _30'30"1 ^ ,. , ,, „,, 

 Index ^_j_g2 ^^ _^q ^^ | Correction + 1' 0" 



Pocket chronometer 

 6" 23'" 50» 



25 48 

 28 16 

 30 55 



32 19 



35 IT 



38 43 



84° 



83 53 



36 



40" 



40 



2* 



, (20" 

 44' ■.' 

 ** 120 



32 \^-^ 



"*" joo 

 j20 

 (00 

 fOO 

 |00 

 (40 

 140 

 (20 

 (00 

 f 60 

 (40 



n 



02 



40 



T = + 21° 



B = 30'".0T6at 410 



T 1 f+32' 

 Index I ^32 



20" 

 00 



—30' 40"' 

 —30 30 



Correction + 4T".5 



, = -^1' 10". 1 



r = — 1' 08". 4 



5 = + 38° 39' 2r'.6 



„= 18"^ 32" 12'. 8 



Sidereal time at mean noon 16'' 35" 



1014 



T 









7i 













aT 



6" 24-=" 



49' 





42° 



18' 



25' 





67° 



11' 



12" 



— 5= 



6 29 



85.5 





42 



04 



05 





68 



24 



20 



— 1 



6 33 



48 





41 



51 



45 





69 



25 



43 



— 7 



6 38 



43 





41 



37 



12 





70 



38 



27 



—12 







— 6'. 3 



Hence 



A r November 19th, 





+ 6= 











Satellite I, disappearance, 



11' 



05'" 



55 











Local mean time of 



eclipse. 



23 



06 



01 











Greenwich mean t 



ime. 



27 



57 



12 











3 ± P.6 



Longitude Port Foulke, 4 51 11 west of Greenwich. 



The correction of the pocket chronometer on local time, January 30th, is obtained 

 by means of comparisons with the three mean time chronometers on that date, and 

 the rates of these chronometers determined between November 29, 1860, and 

 March 8, 1861. 



Observations for time, March 8, 1861. S. J. McCormick, observer. 



Altitudes of the sun. The times given are means of several observations, the corresponding mean 



altitudes are supposed corrected for index error. 



cket chronometer 







2" 58-° 25^= 

 3 00 50.5 



4° 10' 18" 

 4 05 39 



rt = 8" 



6 = — 4° 38' 44" 



hence : — 



? 



85° 46' 25" 

 85 51 16 



t 

 + iO° 50' 00" 

 + 41 26 24 



T = — 15° 





B = 29^5 at 45° 





7- = — 12' 59" 



r, = — 13' 11" 



E 



aT 



+ 10"' 5 P. 3 



—4'" 1317 



+ 10 51.3 



—4 14.1 



Mean 



—4 13.9 



Chronometer comparisons : November 29, 1860. 

 Pocket chronometer. Mean time. 



Correction of pocket chi'onometer = — 6^ 3 

 Chronometers. Correction on mean time. 



18'" 



26^2 



8" 18-" 



19^9 



2007 : 1'' 8" 



—4'' 49'" 



40M 



19 



44.9 



19 



38.6 



1062: 1 9 



—4 49 



21.4 



20 



43.2 



20 



36.9 



740: 1 10 



—4 49 



23.1 



