202 Of th SOLIDS 
Turs equation alfo belongs to a curve of equal attraction ; 
the plane in which that curve is being parallel to AB, the line 
in which the attra¢tion is eftimated, and diftant from it by the 
{pace 6. 
InsTEAD of reckoning the abfcifla from K, it may be made 
to begin at C. If AL or CK=4, then the value of 4 is deter- 
mined from the equation 4° = a® bs — ’, and ifw=h+u4, 4 
being put for CF, v° = at (h wi ue — (b+u)* — a? be + 2’, or 
e+ (btu +h =a® (b+n)%, or + (b+) 40) = 
at (h+u)’. 
WueEn 3 is equal to the maximum value of the ordinate EH, 
(xv. 2.) the curve CGD goes away into a point ; and if b be fup- 
pofed greater than this, the equation to the curve is impoflible. 
Xx. 
Tue folid of greateft attraction may be found, and its pro- 
perties inveftigated, in the way that has now been exemplified, 
whatever be the law of the attracting force. It will be fufh- 
cient, in any cafe, to find the equation of the generating curve, 
or the curve of equal attraction. 
Tuus, if the attraction which the particle C (Fig. 1.) exerts on 
the given particle at A, be inverfely as the m power of the di- 
193.75 
AC” 
AE 
co I 
ftance, or as then the attraction in the direction AE 
will be , and if we make this = ae we haye 
AB 
Bee 
C" +r 
