'220 OCCULTATION OF ALDEBARAN 



Determination of the longitude of Porto-Rico ioest of Paris. 

 Conjunctions at Paris resulting from three suppositions. 



1. By the immersions and emersions at Paris, Gotha and 

 Figueras, reduced to the national observatory. 



2. Supposing 22' 57" difference o» latitude at the conjunction, 

 and making use of the immersions with \" of inflection. 



3. Making use of the same difference of latitude at the con- 

 junction with 2" inflection. 



Conjunction at Paris by observations. 



h / w h i u h / n 



At Gotha. 18 06 30 6 18 06 30 18 06 27 6 



Paris. 18 06 36 9 18 06 31 3 18 06 29 



Figueras. 18 06 35 5 18 06 35 5 18 06 33 3 



Berlin 18 06 33 5 18 06 30 4 



Marseilles 18 06 33 2 18 06 31 4 



Dantzick 18 06 32 18 06 26 I 



Conjunction on three hypotheses. 18 06 34 3 18 06 32 5 18 06 29 7 



Same at Porto-Rico. .' . . . 13 32 41 8 13 32 41 3 13 32 37 7 



Longitude of Porto-Rico on? 4 33 52 5 4 33 51 2 4 33 52 



the three hypotheses. 



h 1 u 

 Mean longitude of Porto-Rico 4 33 51 9 



Supposing 22' 57" difference of latitudes at conjunction and 1" of inflection we have 



the longitude of Paris by the immersions. 

 Conjunction at the national observatory, apparent time,"! 

 by the mean of the observations at Paris, Gotha, Figu- > = 18h 06' 32" 5 



eras, Berlin, Marseilles and Dantzick. J 



% 1 11 



Gotha east of Paris 33 33 



Figueras. ....•••• 2 o2 5 



Ferrol west. . 42 11 



Berlin east 44 10 



Marseilles 12 08 7 



Dantzick 1 05 ]4 o 



Porto-Rico west 4 33 51 2 



If we suppose the proportion of the difference of the earth 

 axes 1-300, it diminishes the difference of meridians between 



Porto-Rico and Paris = — 2" 65 



1" diminution of the parallax, + 2 14 



l" more in the horary motion of longitude. + 3 70 



