of Natural Philosophy. 157 
The erroneous — of the stationary points and retro- 
gradations of the planets in Ch. 4. Part. I. of the sah 
my has been very properly expunged from the present 
tion. An investigation is nab bea (p. 262,) which dives 
- the formula D S Bie Sar for the sine of elongation of 
the superior planet, and d nea ; vee for that of the 
inferior planet, at the time when each is stationary as seen 
rom the other. Instead of these cumbrous formule, which 
require the calculation of th @ velocites, and are unfitted for 
¢ sb have seen the in- _ 
vestigation so conduc so conducted as ‘to terminate in in the equations, — 
cot E=v4( Mad Be and cot = Git a +4). YP (DF) E being the : 
elongation of the superior, and e that of the inferior planet. 
hese expressions are far simpler, besides being confined 
to terms of the distances.* 
ve taken no notice, in the progress of these remarks, of errors 
which are merely typogra aphical, or which might hav a arisen from 
committed rin fibers 4 eae ody 
list of s con Sarg se, i yeas eg eee will - He pcepant be ee 
to rectify 2B nega with their corrections. y 
to the inst editio i 
; am 
a centrifugal (three times) ond 
Book II. Prop. 30. Cor. 6. ec read» 
Ch. yu. cones ye 
and Cor. 2. 
Book IV. ee: bis Schol. 2. table at top. For 12° 2’ 19° 2’ 
Book V. Prop. 5. Exp. 6. pe he metallic cups. 
Prop. 11. line 2. Forelectrified /- unelectrified. 
Prop. 14. Exp. a is Tor positively negatively. _ 
Book VI. ae 17. Exp. sien For Senreng conv - 
26. or 42° es Hi ees 
Book VIE Prop. 13. For half y ear ; : _ half a year. 
ee 40. For eart race lee 4 ight i 
Eee Bi, end of Schol. For pe : ie 
ag. 295. eee. 
3d col aeten He, Gprkal. a “or 1906352 joiease 
— . head of last 
ol. but one: ie mean distances . mean dist. of the earth. 
a 
