[ 197 ] 



at hH. at the time therefore of the ftar's paffage, the moon 

 had fince her own paffage approached the ftar by 60' of mo- 

 tion =4' in time-. 2 H. — 4' or iH. 56' was the true interval of 

 A. R. between thefe heavenly bodies when the ftar paffed. Let 

 us again fuppofe the moon to move at the fame rate in her 

 orbit, and another meridian to pafs over her firft limb when 

 it had 12H. 1' o" of A. R. The ftar fhe was before compared 

 with being a fixed point, will be found by this fecond meri- 

 dian at its permament ftation of 14H. and to get the true differ- 

 ence of the moon's A. R. from the faid ftar at the inftant of its 

 paffage iH. 59' the obferved difference muft be leffened by the 

 moon's increafe of A. R. in iH. 59'=to 59'. 30" of motion, 

 or 3' and 58" of time. 



EXAMPLE. 



Firfl Meridian. 



5 1 limb paffes at 

 Star paffes at - 



H. ' " 



12 o 8 

 14 o o 



Apparent difference of their A. R's. -200 

 Dedudl the moon's increafe of A. R. in 2Hs. o 4 o 



True difference of their A. R's. when the ftar paffed 156 o 



Second 



