BY THE MOON. 221 



If we suppose the polar horizontal parallax diminished 4-", 

 conformably to Laplace's theory, it would increase the longi- 

 tude of Porto-Rico by 8" 5 of time: in this case the longitude 

 ofPorto-Ricowouldbe( = 4,* 33' 51" 2+8" 5) = 4 h 33' 59" 7 

 According to Triesnecker. ... . . 4? 33 58 G 



The variations in the elements, have no sensible influence 

 on the difference of meridians between the observations in 

 Europe. — So that we may consider the above results to have 

 as much accuracy as the observations can possibly be suscep- 

 tible of. 



No. XXXVII. 



The geographical position of sundry places in North America and 

 in the West Indies, calculated from astronomical observations : By 

 Jose Joaquin de Ferrer. 



Read at sundry times, 1805. 

 OCCULTATION OF JUPITER BY THE MOON. 



January 1 5 th, 1799. 



Apparent time. 



Observations. h ' " 



At New-Orleans ) Immersion of the center of Jupiter. . 5 45 46 5 



by Mr. Andrew Ellicott. J Emersion of the center. . . . 7 06 20 



At the royal observatory of T 



the Island of Leon by Don > Immersion of the 1st limb. . . . 13 29 43 8 



Julian Ortiz Canelas. j 



At the national observatory at? T . „t .i„ ,„„,„ i" en io < 



» • . «* ■»« i c Immersion or the center. . . . lj 5U 1Z 5 



Pans bv Mr. Mechatn. j 



Elements by the tables at 13h 00' 00" mean time or 12h 49' 50" 1 apparent time at Paris. 



f Longitude reckoned from the apparent equinox. 



I Latitude. S. 

 Equatorial horizontal parallax. 

 Moon's ^ Horizontal diameter — 3" inflection. 

 1 Horary motion in longitude. 

 I Horary motion in latitude northerly. 

 iHorary augmentation of parallax. 



46 26 38 

 34 26 7 

 55 04 

 30 00 

 30 27 7 

 2 41 1 

 1 4 



S Geocentric longitude. . . . • . . 46 24 46 

 Geocentric latitude. 57 16 



Horary motion in longitude direct. . . , 2 40 



Horizontal parallax. 1 87 



Semidiameter. . ...... 20 33 



Proportion of the equatorial and polar diameters of the earth 334 : 333. 



