TO FIND WHEN THERE MUST BE ECLIPSES. 403 



the moon's ascending node*; and much in the same way as LECT 

 the mean conjunctions of the sun and moon are found N<x ^ I i^ i 

 by the table of the moon's mean motion from the sun. 

 For, collect the sun's mean motion from the node (which 

 is the same as his distance gone from it) for the begin- 

 ning of any gives year, and subtract it from 12 signs ; 

 then, from the remainder, subtract the next less mean 

 motions belonging to whatever month you find them in 

 the table ; and from their remainder subtract the next 

 less mean motion for days, and so on for hours and 

 minutes : the result of all which will shew the time of 

 the sun's mean conjunction with the ascending node of the 

 moon's orbit. 



EXAMPLE VII. 



Required the time of the sun's conjunction with the ascending 

 node in the year 1764 ? 



Son from node. 



80 



To the year after Christ's birth 1753 1 28 10 

 Add complete years .... 11 7 2 3 56 



Mean dist. at beginning of A. D. 1764 9 4 15 

 Subtract this distance from a circle, 



or 12 



And there remains 2 29 55 45 



Next less mean motion for March, 



subtract . 2 1 16 39 



And the remainder will be .... 28 39 6 

 Next less mean motion for 27 days, 



subtract 28 2 32 



And there remains 36 34 



Next less mean motion for 14 hours, 



subtracted .... 36 21 



(Remains nearly) the mean motion of 6 



minutes 13 



2 D2 



