The Cecil Whig. [volume] (Elkton, Md.) 1841-current, 1875-06-19
CLIMATE OF THE ICE AGE.

The science of meteorology has, of late
years, been growing more and more in pop
ular favor. The revelations of the United
States Signal Service, and the valuable prac-
tical deductions that have been made from
them, have created an interest in the sub
ject which will not soon die. And while the
climatology of our own day has commanded
the careful study of our scientists, that of
earlier times in the earth's history has re-
ceived equal, if not profound, considera-
ton. The study of the plants and animals
which previously existed on the globe
including the vexed questions relating to
the development of organic forms-has
largely to do with the climate and state of
the atmosphere that prevailed in those
earlier periods.
1t has long been supposed, and taught by
text book and teacher, that during the car
boniferous age, when the suns heat was
stored up for us in the form of coal, petro-
leum, ETC., the atmosphere was supercharg-
ed with carbonic acid gas; but recent in
vestigations have rendered this extremely
improbable, and some late experiments
have demonstrated that plants are killed
by greater amount of this poison gas
than is ordinarily found in the air. But
doubtless the greatest intellectual capital
has been invested in consideration of the
meteorological conditions of the glacial
PERIOD and the conclusions which have
o1oI h. i IL
apart as the antipodes. While all agree
that the northern part of our continent,
down to 400 of north latitude, was almost
completely covered with sheet of ice from
one to three miles thick, during this period,
some make it season of intense cold, and
others claim that it must have been a time
of moderately high temperature Many
theories have been advanced to account for
the climatic changes which brought the
alterations of heat and cold to our earth
during the past ages. One of these is the
supposition that the solor system, in its
translation through space, may have passed
alternately through regions of extreme
cold and great heat Another is that the
Stti III iitNS SiinhSSSu eHC pooiVioh VI ilS
axis of rotation, because of some great
mountain upheaval between the equator
and the poles. Still another is the wild
supposition that the earth's crust has grad
ually slipped on its nucleus, so as to bring
the equatorial belt nearer to the pole than
usual, and then away from it again. Lyell
has attributed these changes to a supposed
change of place between the land and sea.
He argues that, if the land were accumu-
lated most in the tropics, the vast amount
of solar heat which it would "soak up"
would be carried by currents to the polar
regions, and afford nearly or quite sum-
mer climate to any islands that might be
situated there. And if the land were accu-
mulated about the poles, it would result in
a great diminution of terrestrial heat, be-
cause the water, which is exposed, in this
case, to the direct rays of the sun, has far
less heating power than the land. Prof
Shaler has advanced the idea that these
changes may be explained on the suppose
ton that our sun, like many other suns in
the universe, is a variable star, and makes
our earth warm or cold according as it's
brightness varies. Whether any one of
these is the real cause of past cosmical
climatic changes we cannot say; but we
can reasonably conceive that the first and
the last two may each be considered true
cause.
Among those who believe the ice age to
be one of extreme cold, stands prominently
Mr.. James Croll. His theory for explain
ing the cause of this cold is based upon the
eccentricity of the earth's orbit, the pre-
cession of the equinoxes, and the obliquty
of the ecliptic. The orbit Of the earth is
an ellipse, varying in eccentricity as the
planets are variously situated in their Or
bits, being most elliptical when the planets
draw it farthest from the sun. Its rate of
through the suns center, parallel to the
plane of the earth's equator, it will cut the
earth's orbit in two opposite points, namely
at the vernal and autumnal equinoxes.
The line between these points does not
divide the earth's orbit into equal parts,
on account of its eccentricity. The earth
passes through the perihelion part of its
orbit in seven or eight days less time than
through it's aphelion part. Hence, now our
winter is shorter than our summer, and rice
rsrsa in the southern hemisphere. The
action of sun and moon on the protuberant
equatorial mass of the earth is constantly
changing the plane of the earths orbit, and
hence, also, the position Of the line join
ing it's equnoctial points. These make a
complete revolution in about 81 900 years.
Now, when the earth had it's winter in the
northern hemisphere, while it was in aphel-
ion, its winter was longer than the sum-
mer, hence extremely cold. In this case,
the ice and snow of winter will not be en-
tirely melted during the summer, because
much of the suns heat is taken up in melt
ing ice, and therefore does not amelorate
the temperature. The result is that dur
ing this long period, ice and snow are accu-
mulating in the northern regions. The
vapor from melting ice would obscure the
sun with cloudy atmosphere in the sum.
) mer and thus make the air raw and cold
1t is said by antartic explorers that the
summer there is even colder than northern
regions of the same latitude, though the
3 latter are millions of miles further from
Q the sun.
Another consideration, Mr.. Croll thinks
would make great difference with the colo
at the north pole, when its winter occurred
- in aphelion. All permanent oceanic cur
r rents originate in the Antartic Ocean. Tit
chief one divides into two parts: one goe
north to the East Indies; the other goe
west through the Indian Ocean, is DETECTED
round the Cape of Good Hope, follows VI
the west coast of Africa for some distance
then crosses the Atlantic and forms tw'
currents: the Brazilian, going south, ant
the Gulf Stream, going north. Now tn
sun causes the air at or near the equator t.
;, give place to cold currents from the poles