54 A. Hinrichs on the Density, Rotation, and Age of the Planets, 
Ww 
and the high age of Saturn, have already descended to the 
proximity of this body—as the asteroids will do in the course of 
about one age. 
Finally, it may yet be remarked, that we believe we are able 
to account for the multiform phenomena of terrestrial magnetism 
by the friction of ether on the earth ;” if this theory should be 
admitted as a true physical one, the magnetic needle would be 
directed by the force lost in resistance, or, 10 speak in conformity 
with the doctrine of the correlation of physical forces, the vis 
viva lost in resistance is converted into magnetism, The mag- 
netic needle thus would afford a direct proof of the existence of 
this resistance, as the pendulum of Foucault attests the rotation 
of the earth. 
We believe that our efforts have approached more or less to 
the establishment of the following conclusions : : 
Ist. The negative evidence of the non-existence of a resisting 
medium, as afforded by the motions of the planets during the 
few centuries of accurate observations, is of no weight whatever 
in regar urations of time like those contemplated in the 
theory of the stability of the solar system ; hence it follows, t00, 
that it is unreasonable to expect here that accuracy of numeri 
determinations which so highly distinguishes the predetermina 
tion of astronomical phenomena for shorter periods, but that the 
immensity of time here under consideration admits of no high 
_ ™ Of course; for organized beings are more or less cephalized, till in Jan we 
’ ih {- 
* The only—yet very imperfect—exposé of this theory hitherto published, 1 
Pe etnngactions ai Folge der Bewegung der Erde.in Aether. Copenhageds 
