1855.] 



REMARKS ON THE PLANETOIDS BETWEEN MARS AND JUPITER. 



207 



their discovery, the names of the parties by whom they were 

 first observed, and the places at which the observations were 

 made, will be seen by the following table : — 



PLANETOIDS DISCOVERED^UP TO OCTOBER, 1854. 



ELEMENTS OF THE ASTEROIDS. 



No. 

 1 



Names. 



Date. 



Discoverer. 



Place. 



Ceres. 



1801, January 1. 



Piazzi. 



Palermo. 



2 



Pallas. 



1802, March 28. 



Olbers. 



Bremen. 



3 



Juno. 



1804, September 1. 



Harding. 



Lilienthal. 



4 



Vesta. 



1807, March 29. 



Olbers. 



Bremen. 



5 



Astroea. 



1845, December 8. 



Hencke. 



Dresden. 



6 



Hebe. 



1847, July 1. 



(( 



" 



7 



Iris. 



1847, August ] 3. 



Hind. 



London. 



8 



Flora. 



1847, October 18. 



i( 



" [Ireland. 



9 



Metis. 



1848, April 25. 



Graham. 



Markree castle 



10 



Hygeia. 



1849, April 12. 



Gasparis. 



Naples. 



11 



Parthenope. 



18-50, May 11. 



" 



" 



12 



Victoria. 



1850, September 13. 



Hind. 



London. 



13 



Egeria. 



1850, November 2. 



Gasparis. 



Naples. 



14 



Irene. 



1851, May 19. 



Hind. 



London. 



1.5 



Eunomia. 



1851, July 29. 



Gasparis. 



Naples. 



ItJ 



Psyche. 



1852, March 17. 



" 



" 



17 



Thetis. 



1852, April 17. 



Luther. 



Bilk,Germany 



18 



Melpomene. 



18-52, June 25. 



Hind. 



London. 



19 



Fortuna. 



1852, August 22. 



" 



(( 



20 



Massilia. 



1852, September 19. 



Chacornac- 



.Marseilles. 



21 



Lutetia. 



1852, November 15. 



Goldschmidt. 



Paris. 



22 



Calliope. 



1852, November 16. 



Hind. 



London. 



23 



Thalia. 



1852, December 15. 



" 



" 



24 



Themis. 



1853, April 5. 



Gasparis. 



Naples. 



25 



Phocaja. 



1853, April 6. 



Chacornac. 



Marseilles. 



26 



Proserpina. 



1853, May 5. 



Luther. 



Bilk. 



27 



Euterpe. 



1853, November 8. 



Hind. 



London. 



28 



Bellona. 



1854, March 1. 



Luther. 



Bilk. 



29 



Amphitrite. 



1854, March 2. 



Albert Marth. 



London. 



30 



Urania. 



1854, July 22. 



Hind. 



(( 



31 



Euphrosyne. 



1854, September 1. 



Jas. Ferguson. 



Washington. 



82 



Pomona. 



1854, October 28. 



Goldschmidt. 



Paris. 



38 



Polymnia. 



1854, October 28. 



Chacornac. 



it 



It is worthy of remark that a large proportion of the disco- 

 verers were but amateur astronomers. Dr. Olbers was a prac- 

 titioner in medicine- M. Hermann Goldschmidt is an histori- 

 cal painter, who has resided for several years in Paris. He 

 discovered Lutetia with a small ordinary telescope which he 

 kept in his room. Messrs. Hencke and Luther are both ama- 

 teurs. 



It is also worthy of remark that, in several instances, 

 the same asteroid has been discovered by more astrono- 

 mers than one, quite independently of each other. It was 

 so in the case of Metis, Massilia, Amphitrite, and others. 

 It will also be seen that Mr. Hind's name occurs ten times as 

 a discoverer. Mr. Hind is attached to the private observatory 

 of Geo. Bi.shop, Esq., which was erected in 1836 in the Re- 

 gent's Pai'k, London. M. de Gasparis has discovered seven ; 

 M. Luther three. Only one has been discovered by an Ame- 

 rican. 



I also subjoin a table for which I am indebted to Professor 

 Loomis, exhibiting the longitude of perihelion, longitude of 

 ascending node, inclination of orbit, eccentricity, mean dis- 

 tance from the sun, and periods in days of each of the 

 asteroids whose elements have as yet been accurately deter- 

 mined : — 



No. 



Name. 



Ceres 



Pallas 



Juno 



Vesta 



Astrsea 



Hebe 



Iris 



Flora 



Metis 



Hygeia , 



Parthenope., 



Clio 



Egeria 



Irene 



Eunomia.... 



Psyche 



Thetis , 



Melpomene. 



Fortuna 



Massilia 



Lutetia 



Calliope 



Thalia 



Themis 



Phocaaa 



Proserpina . 



Euterpe 



Bellona 



Amphitrite . 



Urania 



Euphrosyne 



Pomona 



Polymnia... 



.a to 

 o 



2-766 

 2-770 

 2-668 

 2-361 

 2-577 

 2-425 

 2-386 

 2-201 

 2-386 

 3-149 

 2-448 

 2-335 

 2-577 

 2-584 

 2-648 

 2-933 

 2-484 

 2-294 

 2-444 

 2-401 

 2-4.34 

 2-912 

 2-645 

 3-144 

 2-401 

 2-588 

 2-348 

 2-781 

 2-546 

 2-359 

 2-948 



1680 



1683 

 1592 

 1325 

 1511 

 1379 

 1347 

 1198 

 1346 

 2041 

 1399 

 1303 

 1512 

 1518 

 1570 

 1835 

 1430 

 1269 

 1-396 

 1359 

 1387 

 1815 

 1-571 

 2037 

 1359 

 1522 

 1314 

 1694 

 1484 

 1322 

 1849 



» 



0-079 

 •239 

 -256 

 -090 

 -189 

 -202 

 -231 

 -157 

 -123 

 -lOT 

 -098 

 ■045 

 ■085 

 •169 

 •188 

 •131 

 ■131 

 -215 

 -159 

 -145 

 -162 

 -104 

 -240 

 •123 

 -253 

 -069 

 -171 

 -163 

 -069 

 -1.55 i 2 

 -076 i 23 





81° 



173 



171 



103 



141 



139 



260 



110 



68 



288 



125 



235 



43 



187 



294 



151 



125 



150 



211 



207 



80 



67 



68 



36 



214 



46 



94 



145 



356 



308 



33 



<iS 



150° 

 122 



54 

 251 

 136 



15 



41 



227 



317 



302 



120 



179 



28 



11 



259 



16 



31 



99 



327 



59 



123 



135 



303 



175 



87 



120 



54 



27 



3-52 



ORIGIN OF THE ASTEROIDS. 



On the discovery of Pallas in 1802, and after Gauss's calcu- 

 lations had proved that the orbits of Ceres and Pallas were at 

 nearly the same mean distance from the Sun, and that they had 

 nearly the same periods. Dr. Olbers conceived the idea that 

 they were fragments of a large original planet, which had 

 been broken up either by internal explosion or by collision with 

 a comet, and suggested the probability that the labors of future 

 observers might be rewarded by the discovery of other frag- 

 ments, perhaps even smaller than those already found, revolving 

 in similar orbits. In support of this conjecture, it was " urged 

 that in the case of such a catastrophe, as was involved in the 

 supposition, the fragments, according to the established laws of 

 phj-sics, would necessarily continue to revolve in orbits, not 

 differing much in their mean distances from that of the original 

 planet ; that the obliquities of the orbits to each other and to 

 that of the original planet might be subject to a wider limit ; 

 that the eccentricities might also have exceptional magnitudes; 

 and, finally, that .such bodies might be expected to liave mag- 

 nitudes so indefinitely minute as to be out of all analogy or 

 comparison, not only with the primary planet, but even with 

 the smallest of the secondary ones." The conditions which 

 rendered the planetoids exceptional being consistent with this 

 ingenious hypothesis of Dr. Olbers, it was geneniUy regarded as 

 at least a probable tnith, and .•icicntific men at once commenced 

 to speculate on the character of the original planet, its his- 

 tory, its size, and its fate. Lagrange, for instance, instituted 



