•xs.iv 



Acr>rTro?rs and coruections. 



see, at the same time, the paper aud the pencil to be 

 employed, for making a diawiug or a copy of any ob- 

 ject placed before us. 



P. 425. L. 1^, for " XXVn," read, XXVIII. 



P. 464. L. 15, for " other points at," read, at other 

 points. 



P. 477. Last lino but one, after " telescopes,'' in- 

 sert, but with respect to the theory of halos and par- 

 helia, he was less successful than Mariotte had been 

 some years before. 



P. 335. L. 7 from the bottom, for " ecipses," read, 

 species. 



P. .545 . . . Running title. The numbers of all the 

 pages are too great by 20. 



P. 587. L. 15. . 17, for " the attraction . . is pro- 

 duced," read, a current is observed iu its most ex- 

 posed parts. 



P. 588. L. 14, 15, for " on account . . moon" read. 

 These currents, as well as the general current of the 

 sea, have been attributed by some astronomers to the 

 immediate attraction of the sun and moon, and of the 

 satellites of Jupiter, which they have supposed to 

 act in the same manner as the attraction of the sun 

 operates in retarding the lunar motions ; but the fact 

 is, that, according to Mr. Laplace, the disturbing force 

 of the sun produces this effect on the moon only iu pro- 

 portion as it increases her distance from the earth ; 

 consequently no such retardation can possibly be pro- 

 duced by the force of gravitation in the rotation of the 

 sea or of the atmospliere, and the whole effect must be 

 attributed to the operation of meteorological causes, 

 producing first the trade winds, and secondly occa- 

 sionmg, by means of the friction of these winds, a simi- 

 lar motion in the sea. In the case of the atmosphere 

 of Jupiter, the effects of heat can indeed scarcely be 

 supposed to be very perceptible, and the rotation of 

 this planet being extremely rapid, it is not at all im- 

 possible that the satellites may exert an action on the 

 atmosphere somewhat analogous to the retardation of 

 the moon's motion by the disturbing force of the sun. 



P. 565, L. 12, for " Almamoun, was the son", read, 

 Almamoun, the son. 



P. 003. L. 2. for " The observations of the transit of 

 Venus were twice made in the South Seas", read. Ob- 

 servations of the transit of Venus were made with 

 great care in the South Seas. 



At the end, insert. For tlie latest improvement 

 that has been made in astronomy, we are also indebted 

 to the zeal and ingenuity of Dr>01bers,who, in pursuit 



of an opinion which be had formed, respecting the ori- 

 gin of the three small planets from the separation of 

 a larger one into frngments, has been in the habit of 

 of examining monthly that part of the heavens, io 

 which he supposes the event to have taken place, and 

 through whicli each of the bodies must necessarily pass. 

 He has had the good fortune to discover, in this man- 

 ner, a fburth planet, which nearly resembles the 

 throe otiiers in its appearance, except that it seem* 

 to be considerably larger. 



P. C21. L. 22, after " descriptions,'' insert. 



We may form some idea of the effects of this mutual 

 action, by neglecting the force of repulsion, as Clairaut 

 has done, and attending only to that of cohesion. 



P. 622. L. 5 . . 13, for " It may also . . densities," 

 read. This mode of re.isoniiig is however by no means 

 sufficient to explain all the phenoini nu ; for it may be 

 inferred from it that when the attractive power of tlie 

 solid is greater or less than half that of the liquid, the 

 surface of the liquid must, at its origin, be in the 

 same direction with that of the solid, instetvd of form- 

 ing an angle with it, as it often does in reality. But 

 the difficulty may be removed by reverting to the ge- 

 neral principle of superficial cohesion, and by com- 

 paring the common surface of the liquid and solid 

 with the surface of a single liquid, of which the attrac- 

 tive powfer is equal only to the difference of the re- 

 spective powers of the substances concerned. In this 

 manner it may be shown, that if the attractive power 

 of the solid be equal to that of the liquid, or still 

 greater, it will be wetted by the liquid, which will 

 rise until its surface acquires the same direction with 

 that of the solid ; and that iu other cases, the angle of 

 contact will be greater, in proportion as the solid is less 

 attractive. A similar comparison is also equally ap- 

 plicable to the contact of two liquids of different den- 

 sities. 



P. 630. L. 11, for " one," read, we. 



P. 678. L. 7. for " when in contact," read, cither 

 during their contact, or after separation. 



P. 702. L. 9 . . 28. For " Astronomers . . years,'' 

 read, " nor can any sufficient cause be found, in the 

 attractions of the celestial bodies, either for the 

 general easterly trade winds, or for the current of the sea 

 in a similar direction, which appears to be the imme- 

 diate effect of their friction on the surface of the water." 



P. 770. Fig. 172, add. The strap itself must how- 

 ever be made stronger when in the situation B. 



