of the Universe. 107 



netrable to another. By what extraordinary mechanical phce- 

 nomena are these vortices created, and how constituted so as to 

 be able to produce the tides, or cause the motions of comets, 

 since tliese vortices must all run counter to one another, and 

 penetrate each other, and yet wonderfully preserve their motions- 

 entire ? 



14. The comet of IGSO, according to the calculation of Mr. 

 Pingre, when in its perihelion, actually moved with a velocity of 

 1,240,000 miles in an hour. 



The maximum horary motion of a comet descending to the 

 sun from an infinite distance can never exceed 1,395,856 miles 

 from the effects of their mutual attractions. The velocity of the 

 comet of IGSO is a near approximation between observation and 

 theory, and which undeniably corroborates the truth of theiVeu/- 

 toniaa thpory. 



On the other hand, the planet Mercury, whose motion is the 

 swiftest of any planet with which we are acquainted, moves with 

 a velocity of only 103,290 miles in an hour ; and the maximum 

 horary motion of the gaseous medium is but 4512 miles ! For 

 the sun evidently cannot communicate a greater impulse of mo- 

 tion, than that "of its rotation al)ont its axis ! ! Philmpians, 

 pame and reflect, ere reason forsake her empire, and do not 

 persist in this sophistical doctri?]e, unsupported by any authority, 

 false, and replete with absurdities and inconsistencies. 



15. In reference to page 10, I answer that the projectile 

 force was first communicated to the planetary bodies by the 

 hand of the Deity, who implanted in matter the principle of 

 universal attraction, and that no immaterial power is requisite 

 to maintain the planetary motions. It has been demonstrated 

 that the reciprocal actions of the planets and the deviation of 

 their figures from the spherical form, can never produce any al- 

 teration in their mean motions or mean distances. All the in^ 

 equalities in the system are periodical. The planetary orbits 

 change their inclinations. Their eccentricities vary Avithin cer- 

 tain limits, but the greater axes of their orbits, and their periods 

 round the sun, remain perpetually the same. Amidst the multi- 

 plied derangements which affect the bodies of the planetary sy- 

 stem, the general harmony is always apparent; and the little 

 disorders which have so loiig perplexed the ingenuity of astrono- 

 mers seem only to evince the permanence and stability of the 

 whole. What a snl)lime view of the great arrangements of the 

 universe 1 What an affecting proof of the goodness and wisdom 

 of its Author ! 1 



I am, sir, with respect, yours truly, ' 



Tcnn.itaJMgv Aug. 8, 1820. A NewTONI.\N. 



2 XVI. Some 



