374 SPECIAL RESULTS IN THE (JRANOLOGICAL 



The mutual relations of the orbits of the asteroids and 

 the combinations of the orbits have formed the subject of 

 ingenious investigations, first (1848) by Gould ( 6o7 ), and 

 quite recently by ~D' Arrest. The latter says ( 608 ), " it ap- 

 pears to testify in favour of a real or inherent connection 

 between all the members of the entire group of the small 

 planets, that, if we figure to ourselves the natural dimen- 

 sions of their orbits as forming actual material rings, these 

 rings are all so interlinked, that, by taking hold of any one, 

 all the others would be lifted by or found suspended on it. 

 If Iris, discovered by Hind in August 1847, had accidentally 

 remained unknown to us as doubtless is still the case with 

 many other planetary bodies in that region the group 

 would consist of two separate parts : a circumstance which 

 must appear the more unexpected, because the zone of the 

 solar system occupied by these planets is a wide one." 



We cannot take our leave of this wonderful and nume- 

 rous planetary group, without alluding, even in this frag- 

 mentary description of the several members of the solar 

 system, to the bold views of a highly-gifted and deeply 

 investigating astronomer, respecting the origin of the aste- 

 roids and their mutually intersecting orbits. A result 

 derived from Gauss's calculations that Ceres, in her ascend- 

 ing passage through the plane of the orbit of Pallas, comes 

 exceedingly near the latter planet led Olbers to conjecture, 

 that "possibly these two planets might be fragments of a 

 single large planet formerly occupying the wide interval 

 between Mars and Jupiter, but since destroyed by some 

 natural force or catastrophe ; and that we might expect to 

 discover in the same region more such fragments describing 

 an elliptic orbit round the Sun" ( 609 ). 



