The Harvest Moon. 32S 



ascending 1 node, and the other from which she 

 begins to descend below the ecliptic southward, 

 the descending" node. 



The moon's oblique motion, with respect to 

 the ecliptic, causes some difference in the times 

 of her rising and setting, from what, for the 

 sake of perspicuity, I stated in the preceding 

 paragraphs. When she is northward of the eclip- 

 tic, she rises sooner, and sets later, than if she 

 moved in the ecliptic ; and when she is to the 

 southward of it, she rises later, and sets sooner. 

 This difference is variable, even in the same 

 signs, for the nodes recede about 19^ degrees in 

 the ecliptic every year. When the ascending 

 node is in Aries, the southern half of the moon's 

 orbit makes an angle of 5-J- degrees less with the 

 horizon than the ecliptic does when Aries rises 

 in northern latitudes. In fact, the angle is then 

 only 9 j degrees on the parallel of London. The 

 moon consequently rises with less difference of 

 time while in Pisces and Aries than if her track 

 was exactly in the ecliptic. But in the course of 

 9 years and 112 days the descending node is in 

 Aries, and then the moon's orbit makes an angle 

 of 5-J- greater with the horizon when Aries rises? 

 than the ecliptic does at that time, that is, about 

 20y degrees on the parallel of London ; and this 

 causes the moon to rise with greater difference 

 of time in Pisces and Aries than if she moved 

 in the ecliptic. The shifting of the nodes, 

 however, scarcely ever affects the moon's rising 



