THE USE OP THE CELESTIAL GLOBE. 329 



PROBLEM IX. 



To find the place of the moon, or of any planet ; and 

 thereby to shew the time of its rising, southing, and 

 setting. 



Seek in Parker's or White's Ephemeris the geo- 

 centric place 100 of the moon or planet in the ecliptic, for 

 the given day of the month ; and, according to its longi- 

 tude and latitude, as shewn by the Ephemeris, mark the 

 same with a chalk upon the globe. Then, having rec- 

 tified the globe, turn it round its axis westward ; and as 

 the said mark comes to the eastern side of the horizon, 

 to the brazen meridian, and to the western side of the 

 horizon, the index will shew at what time the planet 

 rises, comes to the meridian, and sets, in the same man- 

 ner as it would do for a fixed star. 



PROBLEM X. 



To explain the phenomena of (he harvest-moon. 



In order to do this, we must premise the following 

 things. 1. That as the sun goes only once a year 

 round the ecliptic, he can be but once a year in any 

 particular point of it : and that his motion is almosf a 

 degree every 24 hours, at a mean rate. 2. That as the 

 moon goes round the ecliptic once in 27 days and 8 

 hours, she advances 13i degrees in it, every day at a 

 mean rate. 3. That as the sun goes through part of the 

 ecliptic in the time the moon goes round it, the moon 

 cannot at any time be either in conjunction with the 

 sun, or opposite to him, in that part of the ecliptic 

 where she was so the last time before ; but must travel 

 as much forwarder, as the sun has advanced in the said 

 time; which being 29J days, makes almost a whole 



Note 100. The plac of the moon or planet, as seen from the earth, if 

 called its geocentric place. Note by the Author 



