NATURAL THEOLOGY. 47 



But many of the heavenly bodies, as the sun 

 and fixed stars, are stationary. Their rest must 

 be the effect of an absence or of an equihbrium 



Phil. Trans. 1796, p. 133 :) — " The comet is now centrically on 

 a small star. It is a small telescope star of about the eleventh 

 or twelfth magnitude, and is double, very unequal ; with a power 

 of 287 I can see the smallest of the two stars perfectly well. This 

 shows how little density there is in the comet, which is evidently 

 nothing but what may be called a collection of vapours." This 

 comet is also remarkable for the shortness of its period, about three 

 and a half years, not receding so far from the sun as the planet 

 Jupiter. In the solar system the difference between the two 

 classes of bodies which revolve round the sun, and are retained in 

 their orbits by the solar action, is most marked and distinct. 

 Comets so numerous serve for purposes entirely unknown to us. 

 Indeed, hitherto no probable conjecture has been formed as to 

 those purposes. That they are not the habitations of beings simi- 

 lar to those which exist on the earth is nearly certain. 'J he earth 

 and planets appear wisely adapted, in a variety of ways, for the 

 convenience and preservation of animals and vegetables. The 

 comets are not so adapted. In one case orbits nearly circular 

 were required, in the other they were not required. 



There is another circumstance in which design appears strongly 

 marked, although we cannot explain the purport of it. The pla- 

 nets appear to be placed at distances from the sun, according to a 

 certain law. This was remarked by professor Bode, and that the 

 law was not complete unless a planet existed between Mars and 

 Jupiter. The new planets were afterwards discovered, each of 

 them circulating between Jupiter and PVlars, at a distance from 

 the sun, conformable to the conjectured law.* The cause of more 

 than one planet being found at this distance has, with some degree 

 of probability, been derived from the hypothesis, that a large pla- 

 net has been shattered into fragments, which fragments are the 

 planets Ceres, Vesta, Pallas, and Juno. That wonderful changes 

 occasionally offer themselves to our notice, as wonderful as the de- 

 struction of a planet, is exemplified in the appearance and disap- 

 pearance of a fixed star. A star suddenly appeared in 1571 of a 

 * See first note to Chap. xxv. infra. 



