The Manitowoc pilot. [volume] (Manitowoc, Wis.) 1859-1932, 1883-02-01
Birth and Death of Worlds.

1t has been shown that past geologi-
cal changes in the earth taken place at
the same rate as those which are now
in progress 100, 1000, 900 of years at the
very least would have been required to
produce those effects which have actu-
ally been produced, we find. since the
earth's surface was fit to be the abode
OF life- But recently it has been point
ed out, correctly in all probability, that
under the greater tide-raising power Of
the moon in past ages, these changes
would have taken place more rapidly.
As, however, certainly 100000 of
years, and probably a much longer
time, must have elapsed since the moon
was at that favorable distance for rails
ing tides, we are by no means enabled,
as some well meaning but mistaken
persons have imagined, to reduce the
life-bearing stage of the earth from
duration 100000 of years to q min.
ute fraction of such period The
short life, but exceedingly lively one,
which they desire to see established by
geological or astronomical reasoning,
never can be demonstrated. At the
very least, we must assign 10000, 600
years to the life-bearing stage of the
earth's existence. If we now multiply
this period by seven for Jupiter, we get
period of 60,000,000 years longer.
But take the stage preceding that of
life on the earth. From the researches
of Bischoff into the cooling of masses of
heated rock, it seems to follow that
period of more than 500, 100000 wears
must have been required for the cool
# q tan atl1,s Of
1000 degs. centigrade to one of 200
degs., cooling which has certainly Ia
ken place. Suppose, however. that
these experiments, or the calculations
based on them, were vitiated by some
error so considerable as to increase the
real duration of the fiery stage of our
earth's history more than ten-fold, the
real duration of that period being only
30,000,000 years. Multiply this in turn
by seven. and we get a period of
2lO, 100000 years, or 10000, 900
years longer We ought next to con-
slider the yaporous stage; but the evil
dence on which to form an opinion as
TO the duration of this stage Of a plan
cts history is too slight to be the basis
of actual calculation. Here, as TyndalI
has well remarked. conjecture must
entirely cease But, by considering
only two stages fiery stage and the
life-hearing, or rather that portion of the
life-bearing stage, through which the
earth has hitherto passed-we find the
two monstrous time diflerences-18O,-
000,000 and 60,000,000, or 100000
years in all They mean that, if o. I as
sumption as to the effect of Jupiter's
superior mass is correct, then, suppos-
ing Jupiter and the earth to have start
ed into existence as distinct orbs at the
same or nearly the same time, 240,000,-
600, years must elapse before Jupiter
1vill reach the stage of planetary life
through which our earth is now passing.
Whether the assumption be correct or
not, the time differences between the
stages of Jupiter's life and the earth's
are Of this order. They must be meas
ured by tens of millions, If not by hun
dreds of millions of years. We must
note, however, that the 100000, 900
years correspond with only a seventh
part of that time in the earth's history:
so that we may say that, if our assump-
tons are correct, Jupiter would now
be in the state in which our earth was
81, 100000 years ago. or nearer the be-
ginning than the end Of the fiery stage.
BekgraUiG.