Burlington weekly free press. [volume] (Burlington, Vt.) 1866-1928, 1885-11-06
now THE EARTH IS CHANGING.
The Polar Circle Being Reduced Fourteen
Yards "A Year.

on the changes of the earth, and what we
are coming to in consequence. He goes
on to say, in the course of an exhaustive |
article:
During the whole period of the primary
rocks and the formation of coal strata
tropical heat prevailed from latitude IS |
degrees to latitude 80 degrees-to the |
polar regions, that is. The temperature
was uniform over the whole earth Dur
ing the first half of the secondary period, |
that of jurassic rocks and chalk, the eli |
mate remained the same the same plants
and the same animals are found all over
the globe. During the second half of
the period, however the climate began to
cool somewhat, and deciduous trees made
their appearance, though tropical plants
were still to be found in England and
Denmark. Even to the middle of the ter
tiary period there was equality of climate
in all ATTITUDES ; but the temperature in
Europe fell very gradually, and it is GER
tain that at the end of the tertiary period
there was no ice on the globe, not even
at the Poles or at the top of the highest
mountains. With the quaternary period
II great change took place. The reindeer
was to be found in all parts OF Europe,
the cold was excessive, and the
great Swiss glaciers extended to
the south of France. The glacial
epoch was in full swing, and the uniform
| ity of temperature formerly prevailing
had been destroyed. Then reflex action
! begins the glaciers, and with them the
reindeer and the mammoth retreat as
slowly aus they advanced. At the furthest
point of the glacial extension the cold be-
came SO intense that Il sea of ice covered
half of Russia, all Prussia, Hanover, Hol-
! land and part of England. What, then,
was the cause of this change from uni
| formity to excessive cold over so large
portion of the earth surface And how
! is it that the extent of the cold region,
after having reached its maximum, gra-
dually retreated?
We attribute the change to the detlec-
| ton of the earth's axis from the perpendic-
ular, and then its gradual return toward its
old position In the case of a perpendcu-
| lar axis the climates will be nearly equa-
| BILE all over the globe. There will be some
difference in different attitudes, owing to
the fact that the suns rays are only rerti-
cal at the equator, but it will be compar-
ativcly small There will be no nights
long enough in any part of the planet to
leave time for the formation of Il large
quantity of ice. Consequently all
we have to do to account for the
ages of time when the climate, as
geology tells us, was the same all
over the world, is to imagine the earth
with II perpendicular axis in place of an
axis ut an angle with the plane of the
eclptc as it is now The angle to-day is
% deg 81 min. Q sec. But the Chinese as
tronomer, Choo kung, who measured the
angle loo years before Christ, made it
% deg "a nIin., and subsequent measure
ment, made in b. c. $50, 250 and 80 A. D.
46l, 729. $50, 1000, 1910 1887, $500 and 1880,
by celebrated astronomers, Greek, Chi
nese Arabian and French, give the angle
as follows at the respective dates: %
deg. - min., % deg. Al min, % deg. Al
mn., % deg. 80 min, 23 deg. 80 min. %
deg. "a min, % deg 81 min. 23 deg. 81
min, % deg. 20 min, % deg. y
min., 23 deg. p min. 30 sec
A succession of figures like these conveys
., little meaning to the unmathematical
mind, but the meaning is clear, ueverthe
less The obliquity of the axis has dl-
minished steadily for the last 1000 years
and the dlmnution amounts in all to q
: min. - sec, showing that its tendency
! now is toward the perpendicular at the
. rate of IS sec. every 100 years This mean,
! that the polar circle is being reduced a
, the rate OF 1888 meters-or, roughly, LAG,
, yards-every century, or, AZ yards every
, year, the temperate zone beng increased
9 proportionately. 1t will take the aNi!
: l76, 946 years to move at its present rate
!, through the distance which now separates
! it from the perpendicular.
As long as the axis remained perpendic
ular, the climate, as has been said, wa
uniformly hot, and in Greenland anC
SpitZbergen pomegrantes grew. One da.
had Il slight effect For ages the modi
iication was tritling; even ut the tertiar.
period there was still no ice, and snow
when it fell, soon disappeared. But b.
. degrees the zones were traced. Round tn
Y pole the change was already complete, an,
the radiation of the earth overcame tn
J. solar heat, and the night the day, so tina
masses of ice were formed. The quatel
J. nary period was entered man appeared Ii
v our continent the angle OF obliquity o
i the axis being about fifteen degrees, an
e the polar belt about 1000 miles IN ey
IS tent, finished at the southern par
of Spitzbergen. The glacial epoch had be
d gun. What then was the maximum {
Z. the inclination of the axis when our cart
~ was divided into two belts of extreme col
n (when glaciers covered the greater porto
IA Of EurOpe) and tOrrid heat Not less ceI
% tainly, than thirty-iive degrees-probabl
q nearer forty degrees Taking, howeve
. thirty-tive degrees, and assuming that til
e. deviation of the axis proceeded at the SAN
m rate as its return is going on now, the
~ 262, 900 years ELAPSED between the fir.
movement and the day when the axis b.
~ gan to return. This check seems to ha,
n taken place at the end of the quaternar
y, period, when the earth had assumed muC
~ about the same general condition that "
40 see to-day. 1t necessarily required 9th,
~ thousands of years to effect chang
N of climate in the opposite direction
~, "a The alteration is clearly manifesto
~, in the geological strata by Il
"a immigration and emigration of the rel
~ deer. There would have elapsed the
W. ", since the axis began its backward NOV
IL ment until Notwithstanding thirty-five d
~ gress to be the maximum of inclination
a. a. 81 ,554 years, which with the 1886 yea
TO that have still to be traversed ere the AK
to once more becomes perpendicular, wou
ar give POP 800 years rs the total period b
- tween the first movement and the mome
= of extreme inclination Already Il
glacial period is considered as at an end
Southern Scandinavia and the Swi
glaciers are nothing to what they wer
Nevertheless, $4,000 years must ST
elapse before glaciers disappear. AS
the age of man upon the earth, assumir
,h that he did not appear until the low
stages of the quaternary period in whit
al his bones first are found it is certain tn
=" the climate was much warmer in Euro
then than it is now. On my calculation
at man has been 223, Cos years on the cart
and 3i9, G54 years have passed since the aX
is of the earth first moved out of the perpe
he dicular.
lg
~ "Reminiscences All the Iate Hahn