32 



ASTRONOMICAL OBSERVATIONS 



Reduction of the observations of the end of the eclipse at Van Rensselaer :— 

 Horizontal par. (L at Van Rensselaer=56' 55".62 

 Relative parallax « = . . 56 41.14 



Correction to a 



a' — oi=p= 

 i'—S=q = 



Augmented semidiameter (T 



b' = S + q = 



i'—D=b'= . 

 k'+b'= 

 k'—b'= . 

 a'+p=a = 

 Reduction to true 6 . 

 t, or observed time 



+ 0'.27 

 10" 57" 51».8 

 — 192".49 

 —3361.19 

 936".65 

 + 19= 18'38".5 

 + 21 18.8 

 + 3165.15 

 + 608.15 

 —1661.16 

 — 53™45^6 

 lO"" 55 48.0 



10 02 02.4 



Correction to « +11 ".6 



,=101° 03' 02" 

 it' = 1886". 95 



^l±j^=d'= + 19° 01'59."1 



,n— n = 1853".99 

 +' = 131° 20' 6" 



Reduction of the observations of the end of the eclipse at Dorpat : — 



$'=58° 12' 31". 2 

 Horizontal par. C at Dorpat 

 Relative parallax « . 

 Correction to a 



a. — S = 

 6'- 6 = g = 



Augmented semidiameter C 



«' = «+3= 

 8'_Z)=6'= . 

 k'+V= . 

 k'—b'= . 

 a' +p=ffl= 

 Reduction to true 6 . 

 I, or observed time 



= 56' 59". 13 

 =56 51.25 

 OS. 00 

 le" 32™ 23^0 

 + 1169". 08 

 —2960.85 

 = 936". 13 

 19° 14' 54". 4 

 + 18 08.1 

 + 2915.13 

 + 191.13 

 + 138.8 

 + 4" 29". 7 

 16i> 28 19.6 



16 22 -49.3 



Correction to 6 



,=103° 09' 13' 



yt' = 1886".43 



+ 10". 1 



^+j? = d' = + 19°05' 50" 



m_M=1852".65 

 +'=144° 45' 8" 



We have, therefore, the following expressions for the time of true conjunction in— 



Van Rensselaer mean time 

 Dorpat " 



10'' 02" 43M + 2.08 dr + 2.08 dR + 0.29 dB (phase 1) 

 10 02 02.4 — 2.SS dr— 2.SS dR— 1.90 dB ( " 2) 

 16 32 49.3 — 2.51 cZr- 2.51 rfiJ— 1.45 d5 ( " 2) 



Neglecting the smaller terms dr and dR, ^\e find, from the Doi-pat observations, 

 fJB = — 15".3 ; and substituting this value in the two preceding equations, we 

 obtain the longitude of Van Rensselaer harbor — 



From the commencement of tlic eclipse 

 " end " " 



Adopted longitude, mean value . 



+ 4" 43" 33^9 — 0.29(?5 = + 4>' 43" 38^3 

 + 4 44 14.6 +1.90</-B= + 4 43 45.5 



+ 4 43 41.9 



