G. Hinrichs on Planetology, 139 
é. z. L 
Mercury, .- -.. =, 2056 ele: 5° 19/ 
ees - - - ‘0068 3° 23° beg Oe 
Earth, - - - 0168 o*.. 9 tet 
Mars, = - - - - 0932 Pek 10’ 
Asteroids,® - - - ‘160 T: oo 6° 14’ 
upiter, - - : 0482 149. 13’ 
Saturn, - - - 0561 2° 30’ 48’ 
Uranus, - - - «+ *0466 0° 46’ 55’ 
eptune, - - += ‘0087 te Vi 6’ 
Invar. plane, - 1° 41’ 0° 0’ 
We see how clearly the principal members of the system 
move in one plune, and that this plane is the invariable plane of 
the system ; the great planets deviate less than one degree, the 
principal of the interior planets, Earth and Venus, only 1} de- 
minimum, 
The inclination of the Earth and Venus is greater than that of 
the exterior planets, for the mass of the former is small as com- _ 
Pared to that of the latter; but as Venus and the Karth are the 
great planets among the interior, we see that the inclination and 
‘lade of Mercury’s orbit are much more considerable than 
either, 
“aed gh § 
Considerable perturbation on its development, was so far distant ? 
Ki 
aa Dee ee 
‘6 Mean of the first 72 Asteroids, elements given in Table of Smithsonian Report, 
‘S91, p. 218-219, 
6 . . . 
€ intended in thi 10 gi fuller account of our views concerning the 
development of the enn Ge waste from a letter of Mr. Trowbridge that 
ihe continuation of his article will contain a solution of this problem, I abstain for 
~ Present from publishing my details. 
