The Salt Lake herald. [volume] (Salt Lake City [Utah]) 1870-1909, 1893-11-23
The Measure of Past Ace

fToIeSSor PreStWitch, the well known
savant, has called a halt in the lsnotty
ispecuiauons of modern physicists on
the rate at which changes are taking
place in the surface of the earth. Some
biologists take note of the rate at
Which the surface rises or falls at
The present day, and assume that the
same rate prevailed throughout geo.
logical history; hence they undertake
to tell us how long it took to lift the
continents now inhabited to their pres
ent level For instance. the coasts of
Norway and Sweden are known to be
rising at the rate of two and a half
feet in a century, and North Cape at
the rate of five feet. while the coast
OF Greenland is subsioing at rate
which has caused gardens that were
cultivated in the seventeenth century
to be covered by the tides today. On
this certain scientists have evolved a
formula specifying the rate which the
surface of the earth rises or falls Yet
it is evident that the causes which
produce such movements must vary
in power with the varying stress to
which the crust is exposed from time
to time, and consequently that their
rate of progress is not uniform, but. on
the contrary, highly variable. Such
measurements as two and a half feet
in century fail to account for the
sinking Of the town at the mouth of
the Indus or for the discovery, in strata
of clay far beneath the surface, Of gold
ornaments on the coast of South Amer
lea.
So again with the speculations on
the length of the period which has
elapsed since the world first became
habitable. Calculations have been made
on the number of years required to
cool a. spot which at one time was in
a state of igenous incandescence, and
on the product, one school of physicists
have decided that the world must have
been inhabited for q. million years,
while another holds that twenty mil
lion years are none too many to allow
for the period. Such speculations pos
Sess little scientific value, because we
have no means of knowing how fast
or how slow geological changes pro-
ceeded in former ages. Men of science
have figured exactly how many years
it takes today for an inch of gravel to
accumulate by d river drift, and they
have hence tried to reckon how many
centuries have passed since the bones
of the driftmen were deposited. But
e estimate assumes that the force
Oh the drift was always the same as
it is today. which is quite unlikely.
Until science takes a larger sweep
we must be content with knowing that
the world has passed through various
changes in which its shape, its eli
mate and its elevation have been very
different from what they are now. We
are absolutely without information as
to the length of times which these
various stages coupled. We cannot
even tell how long it took to convert
tropical forest into a bed of bitumi-
nous coal But we are learning; the
limit of geological knowledge at the
close of the last century demonstrates
how fast If our posterity learn as
fast as recent generations have learned
professors may be able at the close of
the twentieth century to form a shrewd
guess at the number of centuries
which divide us from the man of the
quarternary period.