﻿280 



ON THE ASTRONOMICAL COMPUTATIONS 



Of the Sun, 



Much, 

 Moon's Apogee, 

 Moon's Node, 



Mean longi- 

 tude/or mid- 



nisbt. 



=1 42 17 



20 58 28 



7 8 55 



29 27 35 



ik/<?<*« longi- 

 tude at full 

 moon. 



6 21 54 17 



— 2 3 47 47 



11 7 10 21 



4 29 28 16 



Equation 



True longi - 

 /«/& at Jul! 

 ?noon. 



1 47 506 20 7 



3 40 20 — 20 7 



Of the Sun, 



Moon, 



Mean motion. 



59 S 



790 35 



Equation. 



X I' 16" 

 - 47 28 



?>»e motion at 

 full moon. 



60' 24' 

 743 7 



Hence it appears that, at the opposition, the 

 moon will be near her descending node ; for, 4 s 29 

 28' 16" x 6 s = 10 s 29 28' 16", the place of the de- 

 scending node in antecedenlia^ and i2 $ — io s 29 28' 

 1 6"=: i s o° 31' 44" its longitude according to the 

 order of the signs, and i s o° 31' 44" — 20 7' 27"= 

 io° 24' 17'' the moon's distance from her descending 

 node, which, being within the limit of a lunar 

 eclipse, shows that the moon will be then eclipsed. 

 For her latitude at this time, say, as radius is to the 

 inclination of her orbit to the ecliptic, 4 30' or 270', so 

 is the sine of her distance from the node 620' 57", to 



her latitude of 48' 45" (=^^)' 



SIXTH OPERATION. 



From the element? now found, to compute the 

 diameters of the moon and shadow, and the duration 

 of the eclipse. 



The Sun's mean diameter is 

 Moon's 

 Earth's ., 



Tojatt. 



6^00 



480 



l600 



