30 



A S T R O N O M I C A L B S E R V A T I O N S 



Reduction of oI)servation of immersion, first and 

 I. Horizontal paral. at Y. R. . 56' 01". 8 



Relative parallax n . . 55 49.5 



a— s== . . . —104° 10 39 



a'— a=jj = 

 g'_5 = g = 



Augmented seraidiameter <L . 



k'= 



k'-\-b'= . . . . 

 k'—b'= . . . . 

 a' -\-p=a= 

 in — ?i= ... 

 Reduction to time of true 6 



(4,'=328° 32') 



—10 5t.8 



—54 16.4 



921.4 



929.6 



+ 444.3 



+ 1414.9 



+ 149.13 



1759.6 

 + 5™ 05 M 

 20'' 22 10.8 



second contact : — 



II. Horizontal paral. at V. R. 

 Relative parallax jt . 

 a — s= . . . - 



a — o.=p = 



Augmented semidiamuter C 

 k'= . . . . 



k' + b'= . . . . 

 k'—b'= . . . . 

 a'+p=a= 



m — n . . . . 

 Reduction to time of true 6 

 t 



20 27 15.9 



(4,' =326° 59') 



Reduction of observation of last contact — emersion (marked doubtful) : — 

 ([ 's horizontal par. at Van Rensselaer 56' 02". 4 

 Relative parallax « 



a — a=j5= 



6'_g=g= . 

 Augmented semidiametcr (L 

 k'= . 

 k'-^h' = 

 k'—b' = 



55 50.1 



-111° 42 55.5 



—10 29.98 



—54 33.0 



15 21.1 



929.3 



+ 23.7 



+ 1834.9 



fl'+jj=n= 



m — n = 



Reduction to time of true 6 



(4,'=257° 02') 

 Greenwich time of 6 



56' 01". 9 

 55 49.6 

 -104° 24 12 

 —10 57.2 

 —54 16.9 

 921.4 

 913.2 

 + 415.6 

 + 1410.8 

 + 122.15 



1759.6 

 + 4" 09«.9 

 20'' 23 06.6 



20 27 16.5 



—842". 19 

 1759.5 

 —28"" 43M 

 20'' 53 17.3 



20 24 34.2 



Ih 10i» 45».0 



For the time of the true conjunction in Van RensselaCT time, we have from the 

 mean of the two phases of the immersion and from the emersion — 



20'' 27'" 16'. 2 + 2.46 dr — 0.02 dR + 1.31 dB 

 20 24 34.2 — 9.28 fZr — 9.28 d7i+ 9.04 rfZ? 



and omitting dr and dR, we find by subtraction dB 

 kmmtude — 



+ 21", and the resulting 



From immersion (1) + 4'' 43"' 02^5 



(2) 4 43 00.2 S- Mean 4'' 43"° 01 '.2. 

 " emersion (3) 4 43 01.0 



LONCIITUDE FROM THE ObSERVATION.S OF THE SOL.VR ECLIPSE OF M.\Y 15, 1855. 



Observations at Van Ren.«sclaer Harbor : — 

 Immersion, first contact .... 



Emersion, last contact .... 

 Approximate Greenwich mean lime, immersion 



9'' 13'" 39^5 mean time. 12'' 46"" 32\7 .sid. time. 

 10 55 48.0 " " 14 28 58.0 " 



13 57 11.5 

 15 39 20.0 



