New-York tribune., 1895-01-20
AMERICAN LIFE.
ITS PHYSICAL CONDITIONS. ITS PAST HIS
TORY. ITS PRESENT ASPECTS. ITS
FUTURE OUTLOOK

Education and elf-Government. Edited by Ma
eoogy IN Harvard Tnversy Dean Of Law
renee , Scientiac School; Two volumes With VII,
H.. PIP. viii. GAO. p. Appleton & co.
This treatise on America certainly begins at the
beginning. Its purpose is not merely to depict
life at the present day in all its aspects but to
show nearly as may be all the conditions
which have made that life possible. Naturally.
under the guidance of Professor Shaler. has
10 go back some years. say half a billion or
so. to find a time when the conditions were all
one. and that one at the bottom of the sea. AS
different portions Of the continent appear above
the surface of the ocean in the form Of islands.
the scene depicted by the geologist becomes less
monotonous but the narrative really began long
before that time in the eruptions Of lava. which
have left large traces in the West and few in
the East. but which have been worn away or
covered up everywhere else. Under the favoring
protection Of sea more less shallow. life
asserted itself in way which can still be de-
tccted In this distant age, known to the geolo-
gsts the Laurentan time. there appears to
have been dry land as well as sea. for there
traces of sediment which could only have been
cue to the action Of currents triturating and
wearing away the heights But 1t is only their
chemical elements which betray signs Of life In
these ancient sediments; for they did not
main as they were laid down by the water. but
were converted by the subsequent action of water
and heat, or by the pressure of vast deposits
that overlay them in later times. into gneisses.
mica schists and GRANTEES the characteristic rocks
OF the regions east and west Of Hudson Bay.
north Of the st. Lawrence. the Adirondacks, and
In the Appalachian and Rocky mountains. In
the long Cambran period that followed, there
was less disturbance of the original layers Of
sediment, and fossils can be recognized which
show that the waters were overrun with life.
This enormous activity. particularly of creatures
which secreted lime in their shells or otherwise,
or which burrowed and bored and reduced the
mass through which they moved to the consist
ency OF a powder or paste, has a direct rea-
ton to the life of man AT the present day. For
IL Is probable that the chemical action of lime
upon the hard Laurentian rocks underlying the
Cambrian strata developed the deposits OF lime
phosphate. galena zinc. copper. lead and the
more precious metals whi n have been indspen-
sable to the progress of civilization. Only in the
matter of climate. in the phenomena of storm
and seasonal change and rivers and ocean cur
rents can We be sure that the earth then
like what 1t Ia now But even to be Of that
Is much. since 1t amounts to a knowledge that
the main nstrumentaties which made the earth
a possible habitation for man have been steadily
performing the office to which they adapted
for millions Of years. The Surian age. next
after the Cambrian, marked by vast addi-
tions to the surface Of the North American con-
tinent due 40 a rise OF the land. TO the gradual
subsistence OF the sea. which amounts to the
same thing But the epochal significance Of the
Silurian formation is due to the fact that it
tains the earliest relics of animals that had a
backbone. 1t is difficult even for an evoluionist
hi alotin hin r-ith nr
But when it comes to creatures with spinal
axis the case is different. They not very
pleasant animals. those early vertebrates. They
had a hunger that was wonderful, and nothing
disagreed with their dgestions. They were some
thing like garpkes but the most that can be
said about the veracity of the modern pike would
hardly cast a shadow alongside the hendish
eagerness which must be attributed to their re-
mote correlates. America claims the credit. such
as it is. of preserving the remains OF these an
cient rovers But there were also at that time
probabl some animals on land. The evidence
Of these comes from Scandinavia in the form OF
a creature resembling scorpion. forcible hint
Of what the temperature must have been In
high ATTITUDES in those days-in high latitudes.
that is, II the earth turned on the same axis as
at present. There were vegetables above the
tidemark in those ages too. something like the
varied plant and animal life Of the siurian period
resulted in still more copiods additions to the
deposits Of lime: and this fact is directly related
to the life of man on earth, for wherever the
Sur.an levels were laid bare by later geological
processes there was sure to be formed a soil
,,chcr than could be made out of the decomposi-
ton of earlier rocks. Thus the marvellously
fertile soils Of central Kentucky and OF the
neighboring portions of Tennessee and Ohio owe
their great grain producing capacity mainly 10
the lime phosphate which they derive from the
decay!ng remains of the fossils contained in the
underlying rock. Where the beds of this age
have been subjected to considerable amount OF
metamorphism. that mineral veins are formed.
these deposits are apt TO contain notable guam
titles of gold together with the ores OF silver
and lead. Some of the most extensive deposits
OF the above-named metals in this and other
continents are contained In the Silurian strata
It is probable that this considerable store of the
rarer metals was built into the ancient strata
by the action Of certain seaweeds. which separ-
ated the substances from the waters Of the
ocean and accumulated them on the old ocean
bottom"
The Siluran times were marked by an en-
largement of the area OF dry land in America.
But there was as yet no continent. only multi
tude Of islands, the change being marked mainly
I'm the size Of these which were vastly larger
than ever before, and in the addition to their
number Then came the Devonian PERIOD In
which the sea-covered spaces were built up
slowly from island to island. The whole OF the
present Mississippi Valley TO its widest limits
was a shallow sea. which opened at the north
into the Arctic Ocean. Through this sea coursed
the ancient counterpart of the Gulf Stream. and
to its warm current due the coral reefs that
arc found in the Ohio Valley at points where
the islands Of the Appalachian Archipelago must
have trenched upon the primeval ocean. There
is another remarkable phenomenon. exhibited In
the Ohio Valley and In the adjacent portions or
the virginias Pennsylvania and New-fork.