of Natural Philosophy. 157 



The erroneous theory of the stationary points and retro- 

 gradations of the planets in Ch. 4. Part. I. of the Astrono- 

 my has been very properly expunged from the present edi- 

 tion. An investigation is substituted, (p. 262,) which gives 



the formula D-^/ , for the sine of elongation of 



Ml). 



-d'V' 



j y2 y2 



the superior planet, and 6-\ — — , for that of the 



inferior pianet, at the time when each is stationary as seen 

 from the other. Instead of these cumbrous forraulcs, which 

 require the calculation of the velocites, and are unfitted for 

 logarithmic computation, we should rather have seen the in- 

 vestigation so conducted as to terminate in the equations, 



cot E = ^/M^M, and cot e = ^^±^; E being the 



D d 



elongation of the superior, and e that of the inferior planet. 

 These expressions are far simpler, besides being confined 

 to terms of the distances.* 



* We have taken no notice, in the progress of these remarks; of errors 

 which are merely typographical, or which might have arisen from mistakes 

 committed by the compiler in transcribing. We will therefore subjoin a 

 list of such as affect the sense, and as the student will not probably be able 

 to rectify for himself, with their corrections. Many of them are peculiar 

 to the last edition. 



Book II. Prop. 30. Cor. 6. For — read ~T~ 



^'and Coi^a ™^ ^' \ ^°^ centrifugal (three iime^) centripetal. 



Book IV. Prop. 10. Schol. 2. table at top. For 12° 2' 19° 2'. 



Book V. Prop. 5. Exp. 6. For cups metallic cups. 



Prop, 11. line 2. For electrified unelectrified. 



Prop. 14. Exp. line 7. For positively negatively. 



Book VI. Prop. 17. Exp. line 21. For diverging converging. 



Prop. 126. Schol. For 42° 20' 42° 2'. 



Book Vlf Prop. 13. For half year half a year. 



Def. 40. For earth earth's orbit. 



Pp Pp 



Prop. 57, end of Schol. For —-^ — ^5- 



' P— p P— P 



Pag. 295. 8fh col. against Merc. For 14,24.5.28 24.5.28. 



3d col against Herschei. For 1908352 1918352 



Do. head of last )^ ,. , ... „f,u„„nrtii 



, , , > For mean distances mean djst. 01 (he earui. 



€ol. but one. ^ 



