216 



REMARKS ON THE SMALL PLANETS. 



This formula gives the following table for the magnitudes of 50 

 asteroids and for their real diameters : 



Names. 



M. 



Vesta 



Ceres 



Pallas 



Iris 



Hebe 



Eunomia . . 



Laetitia 



Flora 



Juno 



Metis 



Harmonia . 

 Amphitrite 



Massilia 



Parthenope 

 Melpomene 



Egeria 



Hygeia 



Fortuna . . . 



Irene ._ 



Urania.... 



Psyche 



Astraja 



Victoria 



Ariana 



Daphne 



6.5 



7.4 

 8.2 

 8.3 

 8.4 

 8.5 

 8.6 

 8.8 

 8.9 

 8.9 



y. 1 



9.1 



9.1 



9.4 



9.4 



9.4 



9.5 



9.5 



9.6 



9.7 



9.8 



9.8 



10.0 



10.0 



10.2 



Itacfiies. 

 105 

 89 

 61 

 39 

 39 

 46 

 49 

 25 

 42 

 30 

 40 

 33 

 27 

 25 

 21 

 28 

 45 



24 i 

 27 1 



20 j 

 86" 

 24 



21 I 

 14 

 17 I 



Names. 



Euterpe 



Bellona 



Lutetia 



Phocjea 



Thetis 



Fides 



Nysa 



Thalia 



Calliope 



Pales 



Proserpina. 



Leda 



Isis 



Pomona 



Euphrosyne 

 Polymnia.. 



Doris 



Aglaia 



Circe 



Eugenia 



Themis 



Leucothoe . 



Verginia 



Hestia . 



Atalanta 



M. 



10. 2 

 10.3 

 10.3 

 10.5 

 10.6 

 10.7 

 10.7 

 10.7 

 10.8 

 10.8 

 10.8 

 10.9 

 10.9 

 11.0 

 11.3 

 11.3 

 11.4 

 11.4 

 11.5 

 11.6 

 12.1 

 12. 1 

 12.4 

 12.5 

 12.9 



leagues. 

 15 

 24 

 16 

 14 

 15 

 18 

 17 

 16 

 20 

 18 

 16 

 15 

 10 

 13 

 20 

 14 

 21 

 15 



9' 

 11 

 14 



9 



It Avill be remarked that this calculation gives for the diameter 

 of Vesta nearly the same number as the direct measurement, but a 

 much less number for the diameter of Pallas. We are struck, also, 

 at the extreme smallness of some asteroids, such as Hestia, Verginia, 

 Atalanta, Circe, Leucothoe, <fec., which have a radius of scarcely three 

 or four leagues, and whose surface is less than that of one of our 

 smallest departments. A good Avalker might make the tour of one of 

 these microscopic globes in a day. With an equal density, gravita- 

 tion at its surface would be three or four times less than on the earth. 



In short, if we take our computation from the preceding table, we 

 find that the united volumes of the 50 planets above enumerated 

 would give scarcely tlie two-hundredth part of the volume of our 

 satellite. 



X. 



PERTURBATIONS OF THE ASTEROIDS, ETC. 



The investigation of the perturbations of the asteroids has been as 

 yet scarcely sketched out ; the extreme difficulty of the problem re- 

 sults, on the one hand, from the small number of observations of 

 which astronomers can avail themselves, and, on the other, from the 



