Mi/cell anea Curiofa. 343 



43. And the Aggregate of all the Numera- 

 tors is fo many times i, as is the Number of 

 Terms (fuppofe t 9 ) wanting the firft Column • 



, . I — a n t — 1-4-4 . . 



that is t — • , \ and this a- 



n or n 



gain divided by the common Denominator ??, be- 



nt — 1 -h a . , , - nt— I ~ha 

 comes . And therefore <r, 



13 the Line of Defcent by its own Graviry. 



44. If therefore this be added to a project- 

 ing Force downward in a Perpendicular ; or 

 fubdudted from fuch projecting Force up- 

 ward j that is, to or from a fy The D> 



n 



fcent in the firft Cafe will be * ~~ 4 / -+• 



!Lf i 1 g • and the Afcent in the other Cafe 



nn 



, jr — 1 jr. And in this latter 



n nn ° 



Cafe, when the ablative Part becomes equal to 

 the pofitive Part, the Afcent is at the higheft \ 

 and thenceforth (the ablative Part exceeding the 

 pofitive) will defcend. 



45*. In an Horizontal or Oblique Projection, 



having taken - /, in the Line of Projection, 



n 



and thence (at the Angle given) — — g, 



nn 



in the Line of Defcent \ the Point in the Curve 

 anfwering to thefe, is the Place of the Project 

 anlwering to that Moment. 



Z 4 46. I 



