MARS PLANETOIDS JUPITER SATURN URANUS NEPTUNE. 9 3 



47. Aglaia . . . 1857 September . . . By M. Luther Bilk. 



48. Doris ... n ..... M. Goldschmidt Paris. 



49. Pales 

 60. Virginia 



62. Europa . 



63. Calypso 



. . M. Goldschmidt Paris. 



October . . . Mr Ferguson Washington. 



61. Nemausa . . . 1858 January ... M. Laurent Marseilles. 



February . . . . M. Goldschmidt Paris. 

 April , M. Luther Bilk. 



The newly-discovered planetoids correspond to those of older date in minuteness of 

 volume, mean distances from the sun, and the very varying eccentricities and inclinations 

 of their orbits. The superficial area of some of them is not larger than that of many a 

 terrestrial estate. Atalanta has a diameter computed to be little more than four miles. 

 Vesta, Pallas, Iris, and Flora, are the brightest perhaps the largest. The orbits of Pallas, 

 Euphrosyne, and Phocea, have the greatest inclination ; and those of Massilia and Themis 

 the least, coinciding nearly with the ecliptic. Polyhymnia and Juno are the most eccentric 

 in their paths, or deviate most from the circle ; Amphitrite, Ceres, and Egeria, deviate the 

 least. Flora is at the least mean distance from the sun ; Euphrosyne, Hygeia, and Themis 

 at the greatest. To illustrate the intimate connection of the entire family of small planets, 

 it has been remarked, that if the orbits are supposed to be represented materially as hoops, 

 they will hang together in such a manner that the whole group may be suspended by any 

 given one. It was the bold hypothesis of Olbers, when only Ceres and Pallas were known, 

 that they were fragments of a single planet, once revolving in the same region, which, by 

 internal explosion from some cause analogous to volcanic action, or by concussion, had been 

 broken up. He suggested, in harmony with the conjecture, that many more similar 

 fragments might possibly be found. Lagrange computed that the explosive force necessary 

 to produce the disruption, and give to the fragments certain orbits, would not be more than 

 twenty times the velocity of a cannon-ball. This theory, it must be admitted, is strongly 

 supported by the extraordinary number of bodies discovered since it was proposed. But 

 it still remains a theory only. On the other hand, Leverrier and others, who have carefully 

 examined the elements of the planetoids, believe them to have been formed originally as 

 they are, in common with the other members of the system. 



JUPITER, the next in succession after the telescopic planets, is the noblest member of 

 the solar family in his dimensions, and the brightest in his appearance, with the exception 

 of Venus, whom, however, he rivals in splendour, although more than seven times her 

 distance from the sun. His mean distance from the central body is 495 millions of miles. 

 His entire path in space extends over about 3000 millions of miles, an orbit accomplished 

 in nearly twelve years, at a mean rate of twenty-nine thousand miles an hour. Jupiter 

 travels over 4' 59" of the zodiac in a day, somewhat less than one-twelfth of a degree, or 

 30 20' 32" in a year, rather more than a sign. His course in the heavens may therefore 

 be very easily traced. In whatever constellation he is seen on a certain night, a year 

 hence he will be seen equally advanced in the next, and two years afterwards in the next. 

 Jupiter occupies but 9 h 55 m 49 s in his axical rotation. Thus, in the time in which we 

 have one day and night, he has two, each about five hours long, the sun by day and the 

 stars by night, with his own moons, apparently flying across his heavens more than twice 

 as fast as the celestial bodies appear to traverse ours. By this rapid spinning upon his 

 axis, his equatorial inhabitants will be carried round at the rate of 26,000 miles an hour, 

 which is farther than the equatorial inhabitants of the earth are carried by its diurnal 

 motion in twenty-four times that period. Of the stately dimensions of this fine planet, 

 some idea may be formed from the statement, that a chain extending from the earth to 

 the moon would not compass the equatorial circumference ; and that, supposing a sailing 



