Refolution of attractive Pozvers . igj 
refpondent values AL (ci) 9 (for Vh — — anci Vh' ~ 
Vh + hh' = =+=<£), and there refults an equation 
to the fame folid expreffing the relation between the two ab- 
fciffte z = ~Lh and x 9 and their correfpondent ordinates y. 
1.2. If the abfcifs L h does not begin from L, a point in 
the firft given abfcifs AP, but from M a point given out of it, 
it may be reduced to the preceding cafe, by drawing from M a 
line MN = c to the plane of the firft and fecond abfcifife parallel 
to the ordinates pm ; and from N to the firft abfciffa a line 
NO = b parallel to the fecond abfciffe, and fubftituting in the 
equation expreffing the relation between AP, P p 9 and pm for 
AP, P 'p, and pm refpeflively 2:±AO (^), x^b and y—c; 
and there refults the equation required expreffing the relation, 
between the two abfciffre % and and their correfpondent 
ordinates y, of which the firft abfciffa 2; paffes through the 
point M. 
2. To change the fecond abfciffa P p into any other L£, the 
firft abfciffa and ordinates remaining the fame. In the pre- 
ceding figure let L be confidered as a moveable point of the 
firft abfcifs AL, and the fines of the refpeftive angles denoted by 
the fame letters as before, and L h = x 9 AL=z, and hm—y; in the 
given equation for AP, P p 9 and pm 9 fubftitute % — ~ 9 and 
ydtz—; and there will refult the equation required expreffing 
the relation between z and x the abfciffin, and their cor- 
refpondent ordinates y. 
3. Fig 8. To change the ordinates, the abfciftae remaining 
the fame, draw p 'm an ordinate transformed, p'h parallel to 
the firft abfciffa AP, and meeting a fecond abfciffa, of which 
Vol. LXXIX. H h pm 
