BY THE MOON. 219 



Difference of latitudes at the conjunction 22' 50" 73 



Error of tables t • ■ + 8 01 



Difference of latitudes at conjunction 22 58 74 



Supposing the inflection = 1" the difference of latitudes at the conjunction would 



have been 22' 57" 1. 

 Supposing 22' 57" for difference of latitude at the conjunction, we have an error 



in the tables in latitude = — 6' 27 



Apparent latitude by the tables, (a p. 218) . . . . 5 39 52 37 



Apparent latitude corrected. 5 39 46 10 



Aldebaran. ... ■. 5 28 49 00 



Difference of apparent latitude at the immersion. ... 10 57 10 



With 22' 57" difference of latitude at conjunction there results 10' 57" "") for 



difference of apparent latitude at the immersion, and supposing 

 2" of inflection we have true conjunction. .... 18'' 40' 03" 1 

 1" of inflection do. do .... 18 40 05 5 



Note. The altitudes and longitudes of the nonagesime have 

 been calculated with the latitude diminished by the vertical an- 

 gle corresponding to 333 : 334, for the proportion of the axes: 

 I have omitted the forms which I made use of, and have only 

 given the calculation of the parallaxes to shew the method I 

 have used, which is the same with that of Cagnoli. — See his 

 treatise of trigonometry, printed in Paris, page 411 — 427 . 



Determination of the difference of latitudes at the conjunction. 



It will appear by the annexed table of the occultation, as ob- 

 served in the capital of Porto-Rico and different places in Eu- 

 rope, that the mean difference of latitudes at conjunction, 

 (supposing l" of inflection) is 22' 58" OO. 



The emersion at Paris was observed rather late, as appears by 

 a comparison of the observations, and consequently cannot be 

 much confided in ; the observations at Figueras and Ferrol are 

 not the most proper in order to determine the latitudes at con- 

 junction, because the center of the moon passed near to the 

 star, we shall therefore confine ourselves to those of Gotha and 

 Porto-Rico, which give 22' 57" O without risk of an error of l". 



If we diminish the horizontal polar parallax of the d by 4" 

 according to the theory of Laplace, there would have resulted 

 a difference of latitudes at conjunction by the observations at 

 Porto-Rico and Gotha = 22' 56". 



