A, Hinrichs on the Density, Rotation, and Age of the Planets, 43 
- Taking now 2 according to this law as the original distance, 
we find the age # by (12), viz: 
Distance.” Age. Distance. 
Mercury, 60 10 |Jupiter, 680 3°0 
s, 80 *6 |Saturn, 1320 2:0 
Earth, 120 *8 (Uranus, 2600 1:0 
Mars, 200 6 |Neptune, 5160 3-0 
Asteroid, 360 ? Mean age, 2°25 
Mean age, “712 
Although there is considerable variation in each separate 
group, the mean gives a decidedly higher age to the exterior planets 
than to the interior ones, about in the ratio of one to three. 
But if this law is correct, it demands that the relative age of the 
planets increases with their relative distances from the sun (supposing 
no interchange of place yet to have occurred). Consequently 
our determination of the age of the single planets appears to be 
very uncertain, since Jupiter figures with the same age as Nep- 
tune! But it is easy to show that this is simply a consequence 
of our taking » constant, whilst it not only is greatly varying, 
but even varying in different degrees for different planets. For, 
considering 4 as constant,” and for a certain former period g=ng, 
e, being the present value of 9), the constancy of the mass 
gives e7A=93,A, or A,=n3A, i.e. 
64 “et 
 89A~ 89,4, 
n?—=v,n?, (13) 
ulated. 
We must therefore apply a subtractive correction to our calcu- 
the mass of the planet. By doing so 
i  Saeiee we found the equations of condition pretty well satis- 
fi by taking this correction proportional to the mass. For th 
Superior planets we may have (the constant being assumed 01) 
* These distances seem to afford a good average; the law is rigorously applied, — 
for 80 ~60=20, 12 0—80=40=2-20, 200--120=80==2°40, ete. The series is, 
m, m+n, m+2n, m+4n, m-+8n, ete. 
aa Aes probable that 6 is not ee as on el es _—: the reid 
or trying it wi velocity of light r 
{ime whereby we ar cared though different bathe of the heavenly space (ab- 
