188 G. Hinrichs on Planetology. 
All of these three components act to condense the nebula 
X and Y also determine the revolution of the particles, while 
has no such influence, all motions in the direction of thea 
# mutually destroying each other, because 2, y is the invarial 
et A 
plane. Composing X and Y we g 
bn ee enjven, aiesee ieee 
aa 
and directed toward the axis of rotation; r?=a*+y?. _ 
Substituting the first (18) (m = M) in (22) we obtain 
R=u4.6r, 
where 
27 
t= [(1+-4?) are (tg =) —4]. 
_ 4s now # only depends on 4, i. e. on the eccentricity (10) whi 
is constant, the shells being homothetic, we see is at 
given moment for all parts of the nebula the same, hence 
radial force Rin the nebula is proportional to the density 6 and 
distance r from the axis of rotation. . oe 
_ This simple result is of very great importance, as we shall 
in the sequel. 
§ 10. ‘The orbit of the Planets. 
The particles of the nebula had originally motions in all 
rections; but as we assumed the existence of a moment 
proble ae 
We think so, for there are two modifying circumstances | 
byes 
[Humboldt’s Cosmos] :* 
Ping cc aubers in the last column of the following table are not qué 
