MOONS OF MARS. 411 



that it is only under the most favourable circumstances that they 

 can be observed. It is more than suspected that a third, and even 

 a fourth satellite, exists, and the planet will in consequence be 

 subjected to the closest possible scrutiny at all the observatories at 

 home and abroad for some time to come, in order to determine 

 with certainty the number of its attendant moons, and whether 

 they be two or more, to decide their sidereal revolutions, their 

 diameters, masses, and inclinations of orbits. By reason of his 

 , retinue of satellites. Mars is now exalted to equal dignity with 

 Jupiter, Saturn, Uranus, and Neptune; and by the discovery 

 another point is scored in favour of the nebular hypothesists. It 

 was on the night of the 1st January 1801 that the first of the 

 planetoids, Ceres, was discovered by Piazzi of Palermo. Next year 

 Olbers of Bremen discovered .the second planetoid, Pallas, and 

 so constant and searching has been the scrutiny to which the 

 planetoidal zone, situated between the orbits of Mars and Jupiter, 

 has been subjected, that the number of these minor worlds is now 

 no less than 182, the last three in the series, Nos. 180, 181, and 

 182, having been discovered since the beginning of February last. 

 Of these three, two were discovered by Prench observers ; the third 

 by Professor Peters of Hamilton College, U.S., America. This 

 last, however, is suspected to be only a rediscovery, so to speak ; 

 to be identical with Antigone, discovered five years ago by the same 

 indefatigable observer. If this be so, the asteroidal series amounts 

 at present date to 181. In favour of the ingenious hypothesis that 

 accounted for the existence of these minor orbs by suggesting that 

 they might be the fragments of a large disrupted world — of a large 

 planet rent asunder by some terrible internal convulsion — a great 

 deal could be said while the number of fragments was under half a 

 dozen or even double that number, but when the fleet of orblets 

 began to be counted by the score, the disrupted world theory was 

 dropped as no longer tenable in the circumstances. The hypothesis 



