■a 1 6 ■'Mr. maseres’s Method of 
creafes almoft as flowly as the above-mentioned feriesr 
; ~7 + 7~7 + 7 _ ^ + ^~7T + &c, » which expreffes the 
magnitude of a circular arch of 45 0 in a circle vrhofe 
% 
radius is r. 
Art. 17. If a heavy body, or a pendulum, be fuppofed 
to defcend by the mere force of gravity through any 
arch of a circle not exceeding the arch of a quadrant, or 
90°; and the motion be fuppofed to begin from a date 
of reft, and to continue till the bob of the pendulum, or 
the heavy body, comes to the lowed point of the circle; 
and the radius of the circle be called r, the perpendicular 
height, or verfed fine, of the arch through which the 
defcent is made, be called v, and the right fine of the 
fame arch be called s; and n be put for the number 
1.570,796,326,794, 8cc. which exprefles the lemi-cir- 
cumference of a circle whofe diameter is called 1 ; and 
the time of the fall of a heavy body through the verfed 
fine <y, or the perpendicular altitude of the arch through 
which the pendulum defcends, be denoted by v; the 
time of the defcent of the pendulum through the faid 
circular arch, co'rrefponding to the verfed fine or altitude 
v, to the lowed: point of the circle, will be exprefted by 
the product of it x — into the feries 
1.1 w 1. 1. 3 . 3 .7* i->-3-3-5-5 .y 1 >-i-3 3-5-5-7-7 *>* 
2.2 ss 2>2«4*4 j 4 2.2.4*4.6.6 / 2. 2. 4.4.6. 6. 8. 8 j 8 
