505 



THE SMALL PLANETS. 



"We have already, in the general consideration" of the 

 planetary bodies, characterized the group of small planets 



63 Cosmos, vol. iv. p. 422. With regard to the chronology 

 of the discoveries of the small planets, compare pp. 421 and 

 462 : their relations of magnitude to the meteor-asteroids 

 (aerolites), p. 427. With respect to Kepler's conjecture of 

 the existence of a planet in the great chasm between Mars 

 and Jupiter; a conjecture, however, which by no means led 

 to the discovery of the first of the small planets (Ceres), 

 p. 435 and notes 31-33. The bitter reproach which 

 has been thrown upon a highly esteemed philosopher, " be- 

 cause at a time when he might have known of Piazzi's disco- 

 very certainly five months before, but was unacquainted with 

 it, he denied not so much the probability, as much more the 

 necessity of a planet being situated between Mars and Jupi- 

 ter," appears to me to be little justifiable. Hegel, in his 

 Dissertatio de Orbitis Planetarum, composed in the spring and 

 summer of 1801, treats of the ideas of the ancients of the 

 distances of the planets ; and when he quotes the arrange- 

 ment of which Plato speaks in the Timceus, (p. 35, Steph.); 

 1.2.3.4.9.8.27 . . . . (compare Cosmos, vol. iv. 

 p. 432, note 21) he denies the necessity of a chasm. He 

 says only : " Qua3 series si verior naturae ordo sit, quam arith- 

 jnetica progressio, inter quartum et quintum locum magnum 

 esse spatium, neque ibi planetam desiderari apparet." " If the 

 order of nature is more precise than an arithmetical pro- 

 gression, there appears to be a great space between the fourth 

 and fifth place, and that no planet is required there." (Hegel's 

 Werke, Bd. xvi. 1834, p. 28; and Hegel's Leben von Rosen- 

 kranz* 1844, p. 154.) Kant, in his ingenious work, Natur- 

 yeschichte des Himmels, 1755, says merely that at the time of 

 the formation of the planets, Jupiter occasioned the smallness 

 of Mars, by the enormous attractive force which the former 

 possessed. He only once mentions, and then in a very inde- 

 cisive manner, " the members of the solar system which are 

 situated far from each other, and between which the interme- 

 diate parts have not yet been discovered." (Immanuel Kant, 

 Sammtliche Werke, Th. vi. 1839, pp. 87, 110, and 196.) 



