86 OUTLINES OF NATURAL PHILOSOPHY. / 



tween the time and the declination, the latter must 

 be supposed a maximum, or its fluxion must be 

 made equal to nothing. Thence the time of the 

 solstice, and also the declination itself, when a ma- 

 ximum, may both be found. 



86. The length of the year is determined, by 

 comparing together the time of the sun's being 

 in either equinox, or in either tropic, for one 

 year, (found as above), with the time of his be- 

 ing in the same point for another year, distant 

 from the former by a considerable number of 

 years. The interval reckoned in days, and parts 

 of a day, divided by the number of years, gives 

 the true length of the year. 



a, It was soon found, that the year was nearly equal 

 to 365 days. But when two equinoxes, at the dis- 

 tance of 60 years were observed, the interval was 

 found to be nearly 21900 days 5 this, divided by 

 60, gives 365 ; which is nearly the length of the 

 yearr 



&. This, however, is too great ; and more accurate 

 observation has found it to be 365 d .24<2264, or 

 365 d 5*4$' 51".6. BIOT, Astron. vol. n. $ 40. 

 2d edit. 



87- If 



