LIFE OF THE AUTHOR. XXXV 



quite neglected it at Edinburgh, where I might 

 have improved my knowledge by conversing with 

 those who were very able to assist me. I began 

 to compare the ecliptic with its twelve signs 

 (through which the sun goes in twelve months) 

 to the circle of twelve hours on the dial-plate of a 

 watch, the hour-hand to the sun, and the minute- 

 hand to the moon, moving in the ecliptic ; the one 

 always overtaking the other at a place forv. arder 

 than it did at their last conjunction before. On 

 this, I contrived and finished a scheme on paper 

 for shewing the motions and places of the SUD and 

 moon in the ecliptic on each day of the year, per- 

 petually; and consequently, the days of all the 

 new and full moons. 



To this I wanted to add a method for shewing 



o 



the eclipses of the sun and moon; of which I knew 

 the cause long before, by having observed that the 

 moon was, for one half of her period, on the north 

 side of the ecliptic, and for the other half on the 

 south. But, having not observed her course long 

 enough among the stars by my above-mentioned 

 thread, so as to delineate her path on my celestial 

 map, in order to find the two opposite points of 

 the ecliptic in which her orbit crosses it, I was 

 altogether at a loss how and where in the ecliptic 

 (in my scheme) to place these intersecting points : 

 this was in the year 1739. 



At last, I recollected, that when I was with 



Squire Grant, of Achoynaney, in the year 1730, 



I had read, that, on the first of January, 1690, 



