Sa 
D. Kirkwood on Certain Analogies in the Solar System. 213 
“8 =d = 1 : 
= Neal an ea ES oo 
ws - eer neh ) da 
where % ‘ > it 
m = the mass of Mars, 
Bt ci the asteroid planet, 
Wee No 2: Jupiter, 
Yr = the out@# radius of *Mars’s sphere of attraction, 
=theinner- * upiter’s a 
4 = the diameter of the asteroid planet’s sphere of attraction, 
¢' = the outer radius 5 “ 0 i 
9, =the inner ‘* 
d = the mean distance of Mars from the sun, : 
é— “ “ he asteroid planet from the sun. 
‘4 6t 6c “ce 
If the asteroids, however, are considered as independent plan- 
ets, the analogy is still applicable to Mars and Jupiter: Flora, the 
hearest of those bodies, being immediately exterior to the outer 
imit of Mars’s sphere of attraction; and the mean distance of 
Hygeia, the most remote, nearly corresponding with the interior 
limit of that of Jupiter. 
TABLE L. | 
Planetary Elements conforming with Kirkwood 8 Analogy. - 
ABeED pa 
xo 60126 
ee ome, Di f . . x - + 
Planet, Dista t ; 2 em. O . lb 
a next exterior Mass. Period. | Rotation. /Sph. ofat P tery me. 
ee orbit. : ae ‘i 
d b ee pe Pp D es ek 
M ie hm. 8, 
ereury, | -03870981| +3362335 |, ¢2g7q| 8796025 |24 5 283] -20097¢| -088919 112060 
Venus, 7233316 | -2766684| gles |224°7007869| 23 21 21-9) 383396] “136076 ‘247314 
10000000! -5236923| +eslrae |365-256361 | 23 56 4:09} “52134° 380756) -140592 
ars, 1:5236923 | 1544983 ls sade07/696-979645 | 24 37 20-4) +779537| “636601) +142996 
Ast. Planet} 3:068675 | 2-134101 |yaa¢ea7|1969 968692, 060311) -908382 
Jupiter, | 5202776 | 4:3960101| roa'ra7 43325948 | 9 55 26-5) 4876551) 2902761 2-073790) 
91643604 | gebrg |1075921 | 10 29 168/561 7-085359) 1533249) 
30686°8208 |37 192 _ |7-437871| 4879626, 2.598245 
9538786 J 
Fanus, /19-18239 |10-85711 
'30°03950 
ereury’s sphere of attraction, however, extends to a considera- 
ble distance within the orbit. This w: +e; { 
the existence either of a planet or a ring of minute asteroids in- 
terior to Mercury’s orbit ; or, (2) that the original nebulous ring 
was from some cause precipitated upon the sun. For several 
¥ ind’s value, found by a combination of all the observations of the satellite. 
(See Hind’s Solar System, p.136.)— 
