D. Trowbridge on the Nebular Hypothesis. 37 
several others have been discovered in which some change seems 
to have taken ccurate micrometrical measurements 
subject. 
4, We know from observation that all the primary planets 
revolve around the sun in the same direction, and in nearly the 
same plane. The sun rotates on an axis in the same direction in 
which the planets revolve around him, from west to east. e 
period of the sun’s rotation is about 25$ days, which is about 
7zths of the periodic time of Mercury. According to our theory, 
no planet will ever be discovered so near the sun that its period 
of revolution will be less than the period of the sun, viz: 254 
ays, if this number be accurately determined. This is contrary 
to the supposed discovery of Mt. Lescarbault. 
The inclination of the orbit of Neptune, as we have shown, 
corresponds very approximately with that of the invariable 
plane of the Solar System, as our theory requires, e a 
find that the distance between the planetary orbits increases 
with the distance from the sun. The following table will show 
Taste V. 
Planes. ue toe) [ee See ace 
esas? Ce 0-3870981 "200979 
Venus, oy ax 0-7233306 cxraced 0'383390 
MO ee aces 10000000 | Gso3gy03 | 07521348 
lars, 15236923 | 4.644983 0°779587 
ot. Planet, ......<: 3068675 9-134101 0-968693 
oe eR 5-202776 isto) 4876551 
MN 9°588786 pao 8618608 
oe ne ee | 19-18289 iGSENI1O 7°487871 
Membiiie. fgat,., 3003950 
” This Journal, [2], xxvii, 294-5. 
