The morning call., 1892-08-28
Row OLD Is THE WORLD?

At the recent meeting Of the British AS
sociation discourse was delivered by the
new president, Sir Archibald Gerkie, on
one Of the most interesting problems IN
modern scieace-the age of the world. over
a century has elapsed since James Hutton
wrote his Theory of the Earth" which
was the first attempt TO formulate chr0Dol-
ogy Of creation in accordance with the dis
cOveries of science; since then knowledge
has made vast strides, and his followers
have access to n mass of information which
he did not possess. PlayfaIr and Kelvin
improved upon his work, and now Gerkie
and the school TO which he belongs have
gone beyond them. Geologists have ascer-
tained that the rate at which erosion takes
place can be measured; by applying their
scale TO the sedimentary rocks they have
formed an hypothesis as to the time which
has elapsed since erosion began. To put
the proposition in simpler language, the
surface Of the globe is constantly wearing
away under the Influence Of water and
wind. The portions which are worn Of
are carried down to the sea or into hollows
where they are deposited and form sedi-
mentary rocks. II we can ascertain how
longit takes TO form a sedimentary rock we
can figure out when the process of wearing
away and redepositing began.
Sir Archibald states that on a reasonable
computation the stratified rocks attain an
average thickness Of 100000 feet. The ma
teTial Of which they consist was all washed
down from high planes, deposited and left to
stratify. BY the inspection Of river banks
it is found that in places the surface Of the
land which has been carried down as sedi-
ment in rivers has been reduced at the rate
Of foot IN 730 years, while in other places,
where tie land was more stubborn or less
flexible, it has taken $500 years 10 lower the
surface one foot. The de; Osit must be
equal to the denudation. Thus we find that
|hlle some of the sedimentary rocks have
grown foot in 730 years, others have taken
$500 years TO rise that height. Thus the
period OF time that was required to build up
10000 feet of sedimentary rock has varied
according to locality from 73. 600, 600 years to
go, Geo, COO years. Il follows that the active
work Of creation lasted for cycle interme-
date between these two figures. The cycle
varied with endless succession Of periods Of
disturbance by volcanic force and glacial
action, and the frequent submersion of dry
land, alternating with the emerging of con-
tlnents cut Of the seas. These may have
retarded the growth Of sedimentary rocks,
but they cannot have accelerated it.
4 study Of fossils teaches the steady uni-
formi,y with which the work Of creation
proceeded. Since man began TO observe
there has been no change in the forms Of
animal and vegetable life. 4 few species
have disappeared; not one new species has
been evolved. Not only do we find the
fauna and fora Of ancient Egypt as de-
pieted on monuments which are probably
6o00 or 10000 years Old identical with those
which are found IL that country to-day, but
shells which Inhabited our seas before the
ice aye and grew in an ocean whose bed
oyerlay the Rocky Mountains are precisely
the same species that are found in the bay
Of Monterey ana the waters Of the Chesa-
peake. 1t is evident that there has been no
essential change in the conditions OF life
since these animals ana these vegetables
we're first created yet how vast the shortest
period which we can assign to the gap that
divides Us froE that remote epoch.
Little by little, the geologlst is Hitting the
veil which covers the prehistoric record Of
our planet. The era which preceded the age
OF civilized man, with It's vast rivers carry
ing down diluyial foods to the ocean, and
the bursting forth Of mountain ranges from
eoAtractions Of tie earth's crust, has been
painted to the life. But 10 one has exercised
his pencil On that preceding age. when the
forests made way for eiumps of stuBted
birch and willow. incessant snowfalls COW
cred the plains, glaciers erept down from
The north, and gradually a vast sheet Of ice.
half mile thick. drove mankind, with the
mammoth and the reindeer. to those fortu-
nate regions which, like California, escaped
the agony Of the last Ice age. Nor have We
any distinct perception of thar subsequent
age when the ice melted or receded To TIE
pole, or dense tropical jungle grew up in
the morasses 1t had left, swamps steaming
with tropical heat swarmed with uncouth
batrachian and reptile life. trees of mon
str0us growth shed their shaGe over shiny
pools and black ooZe, and in the distance
long mountain ranges whose fontanele had
otyet closed. poured nPyer-ceasing food OF
lava down their sides. This is page Of his
tory which is yet 70 be written, but the
materials are accommodating, and the his
torisn viii not be long wanting.