86 071 the true Measure of a Lunar Cycle. 



must be corrected up to the new style, not by adding 10 days, 

 which is the correction of that calendar to 1582, nor by adding 

 1 1 days, for that is the correction down to the year 17S2, but to 

 the year 1415, which amounts to no more than eight ornine 

 days, and brings the date to June 16th. In 100 years five days 

 are 1237 complete lunations ; therefore to seek in the New style 

 calendar the corresponding New moon in the year 1815, add 

 five days for each century, or 20 days for four centuries, to the 

 corrected date, and the' nearest New moon in the Ephemeris 

 will be the corresponding New moon sought. 



D. 



1415 • New moon and eclipse, Thursday, June 7 



Calendar correction +9 



June 

 1815 400 years and 4x5 days ,, 



Days in June 

 Corresponding New moon July 6 



The corresponding New moon by the Ephemeris for the year 

 1815, was on Thursday, July 6th, at 47 minutes past 1 1 o'clock 

 at night. Subtract the New style date of the New moon 1415 ; 

 viz. June 16 days, 7 hours, 15 minutes, from the date of the New 

 moon 1815, and it will give the number of days by the weekly 

 cycle from Thursday, the epoch of the eclipse 1415, to the 

 Thursday on which its corresponding New moon happened 1815. 



D. H. M. 

 1415 New moon and eclipse, Thursd. June 16 7 15 morn. 

 1815 New moon Thursd. July 6 11 47 night 



20 16 2 

 But nine days for the Julian correction is too much ; for at the 

 rate of 1 1 minutes per annum, the correction amounts to little 

 more than eight days, six hours, from A.D. 325 to A.D. 1415, 

 omitting fractions : therefore to the old calendar date add eight 

 days, six hours; viz. 

 '1415 New moon Thursday, June 7 7 15 O. S. 

 Julian correction 8 6 



N.S. Date June 15 13 15 N.S. 

 Days in June 30 



14 10 45 

 1815 New moon Thursday, July 6 23 47 



Days above 400 years . ., 21 10 32 



In 



