New Haven, Dec. 9, 1864. 
Art. XVIII.—Jntroduction to the Mathematical Principles Uh. 
Nebular Theory, or Planetology ; by GUSTAVUS HINRICHS, 1 
fessor of Physics and Chemistry, Iowa State University. 
(Continued from p. 58.) 
$8. The condition of the primitive Nebula. 
the radius vector drawn out from the center of gravity, ae 
mass, and A the projection of the area swept over by 7° 
(5) 
or, as the centrifugal force y of the particle m with respect * 
principal axis is 
tad ee . F ‘ ok 
while, at least for a very small unit of time, «) : 
=o r?, ‘ . . 
we have also Emrt yt = 20. ee 
On account of the resistance of the ether, C will not be 
constant, but decrease in time; still it is apparent heh sing 
approximation, we may neglect this resistance by con é 
strictly constant. | ee 
