Stevens County tribune., 1879-10-23
The Glacial Period,

No fact in geology is more clearly de-
monstrated than that IN some remote pc
riOd 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 IS.
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 locality.
In both Europe and America are found
the bones ef animals, the survivors of
of which are now to be found In the high
Arctic latitudes, and those of some ex-
tlnct species, such as the mastodon, the
woslly 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 etfecteds Not by any
cataclysm or CONFUSION of nature, though
that theory was once maintained. The
work of subsidence was gradual, as also
the emergcnce 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 ingeniensly
demonstrated by Mr.. 81. 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 earth's axis is
not always parallel to itself. 1t is sub
ject to very slow gyratory motion in
an opposite direction to the revolution of
the earth, molten estimated at about so
degrees 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 elipt1cal 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-
noctial 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 be 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
southern Hemisphere is the case now
That hemisphere has now winter of 187
days and summer of 179 days.
1t may be reasoned from this that more
ice accumulates at the South Pole during
, the long winter than is melted in the
short summer. And such is found to be
> the fact. According to Mr.. Norton the
ice-cap of the Antarctic continent, abou
900 miles in diameter, is gradually &C
cumulating. The Arctic ice-cap is muct
smaller, and honeycombed at that by the
warm interoceanic currents pouring con
stantly upon it.
Mr.. Norton tells us that if we assign
9 an average thickness of $4,000 feet to thu
= Antarctic ice-cap, tive should have 1
q mass of Ice large enough to displace tht
earth's centre of gravity nearly mile tt
the south of the CENTRE" and that grad
ual displacement would produce ian i'm
n percptible drainage of the oceans from
+ the north to the south, and the gradual
|, emergence of northern and submergenc,
r of southern continents"
t This is what is gradually going on
s The geologists assert that the northern
t continents are slowly rising, and that thu
: islands of the South Pacific are sinking
: or rather, according to Mr.. Norton's theo
ry, the water is slowly draining from til,
northern, and accommodating in the south
g ern hemisphere. The process will con
! tinue for some thousands of years t.
t. come, until, Through the submergence O
It southern lands and the extension of tn
y Antarctic ice cap, the condition of tn
}, southern hemisphere will approximate t
q that of the northern continents durln
:, the glacial age:'' Thus each hemispher
s passes through alternate periods of pre-
n ponderance of summer, or winter, eac
If period being about 10,500 years.
l. According to astronomical calculation
g our present great northern summer com
d menced some $500 years ago. Whll
n the Southern Hemisphere is undergoin
a. slow refrigeration and gradual submel
: gence. 'The process" says Mr.. Merton
d ''has passed its middle, but not its Gu
IN mlnation. even as the greatest averag
Of cold of our ordinary winter is nearer th
t. vernal equinox than the winter solstice
ic In about two thousand years from now, h
D. thinks, the southern continent will |
g. still more deeply deluged; the Antarti
ID ice cap will have extended several hui
I'd dred miles northward, and the glacier
ae which have already appeared among tt
:h Andes, will have covered the plateaus
We Patagonia and Chill. Nevertheless mai
it kind will not then witness the utmo
he possible degree Of refrigeration, '.becau
T. the ellipticity of the earth's orbit is no
less than it has been at certain periods
It's the past, and will be again in the reno
Nv future"
ct Mr.. Norton might have strengthen,
in his theory of this gradual change, due
n the procession of the equinoxes, by cit
10 tions from the writings of the ancien
at beginning with Heredotus and comll
OIL down to the first century of the Christi
we era. In the time of the ''father. of b
rse tory" the land occupied by the scythia