i ^ fyliJceUanea Curiofa. 



It remains now* that we give the Rules for 

 the Calculation, and ihew the Way of deter- 

 mining the Place of a Comet feen, by thefe 

 Numbers. The Velocity of a Comet moving in a 

 Parabola, is every where -to the Velocity of a Pla- 

 net defer ibing a Circle about the Sun, at the fame 

 Diftance from the Sun, as *\f 2 to i . as appears 

 from Cor. 7. Prop. 16. Lib. I. of the Princip* 

 Phil. Nat. Math. If therefore a Comet in its 

 Perihelium were fuppos'd to be as far diftant 

 from the Sun as the Earth is, then the Diurnal 

 Area which the Comet wou'd defcribe, wou'd 

 be to the Diurnal Area of the Earth, as \j 2 to 

 1. And confequently, the Time of the Annual 

 Revolution, is to the Time in which fuch 

 a Comet wou'd defcribe a Quadrant of its 

 Orbit from the Perihellum, as 3.14159, &a 

 (that is the Area of the Circle ) to \/^. There- 

 fore the Comet wou'd defcribe that Quadrant 

 in 1 09 Days, 14 Hours, 45 Minutes } and fa 

 that Parabolick Area (Analogous to the Area 

 POS) being divided into 100 Parts, to each 

 Day there wou'd be alotted 0.912280. of thofe 

 Parts j the Log. of which, -viz.. 9960128, is 

 to be kept for continual life. But then the 

 Times in which a Comet, at a greater or lefs Di~ 

 fiance, woifd defcribe fimilar Quadrants, are as 

 the Times of the Revolutions in Circles, that is, in 

 the Scfqui flic ate Ratio of the Diftances : And 

 fb the Diurnal Areas, eltimated in Centefimal 

 Parts of the Quadrant (whkrr Parts we put for 

 Meafures of the mean Motion, like Degrees) 

 are in each, in the Suhfefquialtera Proportion 

 of the Diftance from the Sun in the Perihelion. 



Thefe 



