36 G. Hinrichs on the Density, Rotation, and Age of the Planets. 
Art. IV.—The Density, Rotation and Relative Age of the Planets} | 
by Prof. Gustavus Hinricus, Iowa State University. 
of moving in vacuo suffer some, however slight a resistance in 
moving through ether, then the analytical demonstration loses its 
physical import. 2 
The metaphysician, in contemplating the ardor wherewith this 
doctrine is advocated cannot but see in it a more refined form 0 
the doctrine of ancient philosophy that the earth is about equal 
to the universe; and the theologian might find the stability of 
the planetary system opposed to the prediction that nothing 
is eterna below. , 
_Yet this is not the place to decide the latter questions; we 
} 
* Olmsted’s Astronomy by Snell, $384 
