Evening star. [volume] (Washington, D.C.) 1854-1972, 1891-08-08
The Age Of the World.

from the oentlemans Magazine.
Assuming that the average rate Of deuuds-
ton in past geological ages did not materially
differ from what it is at present, and that The
total quantity Of stratified rock would, il uni-
formly spread over the whole globe. form q
layer 900 feet in thickness, we have . total
period Of 1000 multiplied by 5000 multiplied
by 4. or "a ,0O0, 900 years. This, however, only
represents the time necessary TO deposit the
rocks which have been formed by liquidation
from older rocks, and these again from rocks
OF still greater antiquity. Assuming that the
existing stratified rocks have thus passed three
tiries through denudation aud deposition, Ne
have period Of 72, o00, 900 years.
DIR. Haughton, calculating from the observed
thickness of the rocks down to the miocene
tertiary, and assuming period OF s.6l6 years
Tor each foot deposited on the ocean bed linda
Tor the age OF the stratified rocks, q. period OF
LOIS, f5o,o00 years. Assuming the rate of de-
mutation, however, as ten times greater in am
cient times than at present. and adding one
third for the period since the miocene tertiary
he arrives at a final result OF zoo 600 600 yesrs
Dr.. CroH doubts the validity of Prof. Haugh-
tons assumptions especially the total thickness
he assumes, namely, III, 200 feet, over thirty
three miles
Mr.. A. II. Wallace. adopting DIR. Haughton's
thickness, but assuming the sediment to be
deposited along a belt of thirty miles wide
round the whole coast line Of the globe, finds
with an assumed denudation of one foot in
5000 years, period of q, 600. coo years. This
however, on DIR. Croll assumption of reforms-
ton and denudation repeated several times
would be merely a fraction of the time required
DIR. Croll further shows from the evidence Of
remarkable faults" in various parts of the
world, with 'downthrows" ranging from SOC
to 20, 900 feet, the enormous amount Of solid
rock which must have been denuded on the
surface of the earth during the progress Of
geological history. He estimates that three
miles Of rock have been removed since the be-
ginning of the old ned sandstone. This would
indicate period of $1,000. 600 years. Aseum-
ing that the period before the old red sand
stone was equally long, we have 30, 600 600 years
as the minimum duration Of geological time"
These enormous periods Of time do not how
ever, seem to satisfy the deman is Of the biolo-
gists and the supporters Of the Darwinian
theory. Judging from the fact that almost
the whole of the tertiary period has been rs-
quired to convert the ancestral orohippus into
the true horse" Prof. Huxley believes ''thss in
order to have time for the much greater change
Of the ancestral ungnlatta into the two great
odd-toed and eyen-toed divisions (of which
change there IL no trace, even smong the ear
hest Eocene msmmals) We should require Q
larger portion, il not the whole, Of the Mesozoic
or secondary period" and still longer periods
are demanded Tor the evolution of other ami
mails, 80 that on the lowest estimate, We muse
place the origin Of the mammals very far back
in Paleozoic times" Mr.. Wallace speaks a
possible periods Of zoo, 000, 900 and even 5oo,-
DOC, 900 Of years.