The Worthington advance. [volume] (Worthington, Minn.) 1874-1908, 1879-10-23
The GLACIAL Period.

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monstrated than that IN some remote pc.
Rod of the past the Northern Hemisphere
OF the globe down to the fortieth paral.
lei OF latitude was submerged and
capped with ice as Greenland now ls
That was the glacial period, the traces
OF which are found on the surface of EN-.
bedded rocks, in the morains of glaciers,
and the bowlders which were carried in
those vast morning rivers of ice and de-
posted at great distances from their ma
tive LEGALITY.
In both Europe and America are found
the bones Of animals, the survivors Of
OF which are now to be found in the high
Arctic latitudes, and those of some ex-
tlnct species, such 40 the mastodon, the
woolly hippopotamus and aurochs crea-
lures that could not live in Southern Eu-
rope or America. The race Of which the
Esquimaux, the Firms, and Lapps are a
remnant, then spread over the continents,
and lived by hunting and trapping the
various animals that belonged to the age
of ice.
But how was the change Of Topography
and OF climate effected2 Not by any
cataclysm or convulsion of nature, though
that theory was once maintained. The
work OF subsidence was gradual, as also
the emcrgcnce Of the land. 1t was due
to what is astronomically known as the
procession Of the equinoxes. At least,
this theory is now generally received
among scientists, and Is ingenionsly
demonstrated by MIR. H. B. Norton in
the October number of the Popular
Monthly.
We could not, without the aid of dia-
gram, illustrate the nature of this process
sion. Sufficient to say the earths axis Is
not always parallel to itself. It is sub
ject to very slow gyratory motion in
an opposite direction to the revolution Of
the earth, molten estimated at about so
degrees 8 minutes year. The rate Of
this motion having been ascertained, it
Is easy to calculate the length of time re-
quired before the earth will occupy the
same position with respect to line
drawn through the greatest diameter of
Its elhptlcal orbit that 1t occupies to-
day.
This period is estimated at $1,000
years, and is called the Great Year. In
computing this long procession of eQui-
noctlal changes, it will come to pass that
when the earth is at its greatest distance
from the sun, the South instead of the
North Pole will he turned toward it, and
the succession of the seasons will be re-
versed. That is to say. our winters will
be longer than our summers, as in the
1c,>h &c <hn
That hemisphere has now a winter of 1877
days and a summer of 179 days.
Itmay be reasoned from this that more
ice accumulatcs at the South Pole during
the long winter than is melted in the
short summer. 'ni such is found to be
the fact. ;!cc",iiny tu Mr. Norton the
ice-cap of the Anturctic continent, about
3 900 miles in diameter, is gradually ac-
cumulating. The Arctic ice-cap is much
smaller, and honeycombed at that by the
warm inteloceanic currents pouring con-
stantly upon 1t.
Mr.. Norton tells us that if we assign
an average thickness of $4,000 feet to the
Antarctic ice-cap, 1--WE should have a
mass OF Ice large enough to displacc the
earth's centre of gravity nearly mile to
the south of the centre, and that grad
ual displacement would produce IAN i'm
percptible drainage Of the oceans from
the north to the south, and the gradual
emergence of nurtnern and submergence
of southern continents"
This is whist is gradually gong on.
The geologists assert that the northern
continents are slowly rising, and that the
islands of the South Pacific are sinking,
or rather, according to Mr.. Norton's theo-
ry, the water is slowly draining from the
northern, and accommodating in the south
ern hemisphere. The process will con-
tinue for some thousands of years to
come, until, "through the submergence of
southern lands and the extension of the
Antarctic ice. cap, the condition of the
southern hemisphere will approximate to
that Of the northern continents during
the glacial age" Thus each hemisphere
passes through alternate periods Of pre-
pOnderancc OF summer or winter, each
period being about 10, 500 years.
According to astronomical calculations,
our present great northern summer COM
menced some $500 years ago. While
the Southern Hemisphere is undergoing
slow refrigeration and gradual submcr-
gence. THE process" says Mr.. Merton.
"has passed its middle, but not its cul-
mlaation, even as the greatest average
cold Of our ordinary winter is nearer the
vernal equinox than the winter solstice." :"
In about two thousand years from now, he
thinks, the southern continent will he
still more deeply deluged; the Antartic
ice cap will have extended several hun
dred miles northward, and the glaciers,
which have already appeared among the
Andes, will have covered the plateaus of
Patagonia and Chilli Nevertheless man
kind will not then witness the utmost
possible degree Of refrigeration, ''because
the ellipticity of the earth's orbit is now
less than it has been at certain periods of
the past, and will be again in the remote
future
Mr.. Norton might have strengthened
his theory Of this gradual change, due to
the procession of the equinoxes, by cita-
tions from the writings of the ancients,
beginning with Heredotus and coming
down to the first century Of the Christian
era. In the time Of the ''father of his
tory" the land occupied by the scythians
was described as one of perpetual snow
and almost, if not quite, unlnhabited.
In the time of Cesar the grape and other
fruits of temperate climate were not
grown north of Italy, and even in the
land Of the sun the winters were more
severe, the frosts more frequent, and the
snow more abundant. This climatic
change has been attributed to the cult
vation of the soil, the drainage of the
lana, and the cutting down Of the vast
forests. But it is still going on. as the
gradual recession and disappearance of
the glaciers among the Alps show. Their
fresh moraines testify to time within a
few hundred years when they reached
down much further into the valleys. Just
as they are disappearing among the Alps
and other ranges of mountains in the
northern hemisphere, they: ire forAing
among the higher Andes, "a phenomenon
in entire harmony with Mr.. Norton's
theory.