On the true Measure of a Lunar Cycle. 83 



Astronomical time. D. H. M. Civil time. D. H. M. 

 1801 # New m. Sept. 7 17 39 Tuesday, Sept. 8 5 39 

 1820 ® New m. Sept. 7 152 Thursd. Sept.7 1 52 aft. 



8 13 8 13 



By the weekly cycle, 

 1801 Days 6937 Tuesday Sept. 8 5 39 morn. 



6968 Wednesday Sept. 

 1820 6939 Thursday Sept.7 1 52 aft. 



8 13 



The measure of this cycle is 6939 days, 8 hours, 13 minutes, 

 for 235 lunations; viz. 



235 Lunations from new moon to D. H. M. 



new moon by Ephemeris . . . . 6939 8 13 



10 Julian years 6939 18 00 



Diff. 9 47 



This difference is to be imputed to the same known cause re- 

 marked above, as I shall prove from a further examination of 

 this cycle, and a comparative statement of the quarters in each 

 lunation : 



D. H. M, 

 From new moon Sept. 1801 to new moon Sept. 1820,6939 8 13 

 From first quart. ,, to first quart. ., 6939 23 31 

 From full moon . . to full moon , . 6939 23 24 

 From last quart. .. to last quart. .. 6939 16 47 



Subtract these differences from 6939 days, 18 hours, in which 

 period are contained 235 mean lunations, at 29 days, 12 hours, 

 44 minutes, 25 heconds, 31 thirds, 51 fourths, Julian time un- 

 equatcd. 



L 2 The 



