160 ASTRONOMICAL OBSERVATIONS. 



Occultation of o in Sagittarius, by the disk of the Moon, observed 

 by J. J. de Ferrer, in Veracruz, August '25, 1195, with an 

 achromatic Telescope of Dolland 27 feet long. 



h 1 11 h 1 11 



Immersion in apparent time, 9 32 55, and in mean time 9 34 31. 4 



Veracruz west of Paris 6 33 42. 8 



Immersion in mean time at Paris 16 8 14. 2 



O 9 U 



Right ascension of the sun at the time 154 46 10 



c •». • ^R'S»t ascension 283 6 21. 2 



o Sagittarius i c °, ,. nn i to 



& £S. declination 22 1 18 



Apparent obliquity of the ecliptic 23 27 51 



c .„ . t Longitude 282 08 9. 5 



o Sagittarius > g gg^ 53 28. 5 



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



o ' '/ I II 



Correct latitude of Veracruz = [19 11 53—6 23] 19 5 30 



Logarithmic radius at Veracruz 9,999 859 



Equatorial horizontal parallax of the ([ 55 50. 2 



if 



Apparent diameter of the J — 3 inflection 30 47. 8 



Parallax in longitude ■ 16 56. 5 



Parallax in latitude 34 38. 2 



S. latitude of the moon by the theory of Laplace 1 30 13. 6 



On the 25th & 26th -August, the moon was observed in the Royal obser- 

 vatory of Greenwich, and comparing these observations with the theory 

 of Laplace, there results the following error in the theory. 



a ii 



On the 25th, in long : = X 0. 8 in lat. =X 6. 5 



26th — 1. 6 x T. 9 



It results from these elements, that the true latitude of the moon at the 



moment of immersion was 1 30 20. 5 



Difference of the apparent latitudes between the. (J & o Sagit 2 13. 8 



True conjunction in Paris according to the Greenwich observations in 



mean time 16 4 58. 9 



Conjunction at Veracruz, by the immersion 9 31 16. 1 



Longitude of Veracruz, W. of Paris 6 33 42. 8 



There was no corresponding observation made in Europe, 

 but as on that and the following day, the transit of the moon 

 over the meridian was observed in the Royal observatory at 

 Greenwich, I was enabled to correct the error in the lunar 

 tables, and found the longitude of Veracruz to be (as above) 

 6 h 33' 42". 8 west of Paris. Citizen Mechain made the lon- 

 gitude, from the same observations, (> h 33' 54". 9. This dif- 

 ference, although very small, might happen, if he was unac- 

 quainted with a remark published by the Rev. Nevil Maske- 

 lyne : That the transits of the stars were observed by his assistant 

 1). K. and that of the moon by Maskelyne himself, who after 



