Evening star., 1936-02-29

within relatively lew days, now
long 1t will last. ..--. .
It is much more difficult to get any
adequate picture of any Of the others.
Nobody ever has succeeded in doing so,
as yet. There are Winters and Sum-
mers Of the ages and Of the centuries.
For about 500 900 900 years there has
been life on earth. During this un-
imaginably long span Of time there
have been millions of years when
Greenland was covered with temper
ate zone forest and other millions of
years when the District of Columbia
was on the edge Of a great ice sheet.
Cold period always has succeeded
warm period, and vice versa. Nobody
knows the reason why. There has
been, apparently, no regularity in the
swings. Some ice ages have been long
and some short. The swinging Of
climate is not like the swing of a
pendulum-so far as climatologists
have been able to determine.
It is entirely possible, even probable,
that superimposed upon these climatic
cycles which can be expressed in geo.
logical time scales only. there have
been shorter cycles whose phases have
endured only for few centuries.
Very likely Europe was consistently
colder than it is today during the So
called Dark Ages and began to get
warm about the time of the Renais-
sance.
But superimposed upon these cycles
of Notwithstanding between them
and the cycle of the year-are much
more definite cycles of which Mr..
Kincer has made an intensive study.
They run for about so years from peak
to peak. For a time the temperature
of the earth-taken as a whole-will
rise consistently from year to year.
Then, after it reaches a certain high
point, it will fall consistently. The
phases of such cycles run anywhere
from 10 to 40 years. This fact
renders them of small value for long
range forecasting.
Now for the past 20 years the earth
and more specifically the North
American continent-has been in one
of these Genealogical upswings. BY
and large, taking the continent as a
whole and disregarding local vagaries
of weather, it has been getting warmer
and warmer. There has been rather
consistent piling up of an excess OF
heat. There has been plenty of cold
weather, but the general trend has
been unmistakable. 1t has had some
rather picturesque and tragic conse-
uuences-such as the great droughts of
1880 and 1884 and the great dust
storms which brought such tragedy to
the Western plains.
THERE is every indication that this
= upswing of the cycle has reached its
highest point and that this Winter
marks the beginning Of the downward
swing. How long it will continue no
body knows. There is no great reason
to be alarmed. This does not mean
that next Winter will be colder than
this Winter, the next Winter colder
still. and so on. 1t only means, pro-
viding the rather vague indications are
correct, that during the next 10 or
more years there will be appreciaoly
more cold weather than during the
last decade. 1t is likely that some OF
the Winters will be quite cold. There
will be necessarily a piling up OF cold
somewhere. provided the cycle runs
true to form.
Tested on the basis Of daily, weekly
or monthly temperatures at any par
ticular spot in the United States, this
cycle probably would not be at all ap-
parent. It would be masked by the
relatively much greater effect OF local
and seasonal variations. Mr.. Kincer
extracts the main trend from these by
a rather complex statistical method
the computation Of the floating
mean" This is bit tricky to the
amatuer. 1t is apt to be set down,
at first glance, as a mathematical
stunt. Actually 1t is a scientific
method of getting at an underlying
reality. ...
The undulations of the curve of this
floating mean probably mean as much
to humanity at large as any minor
war. They may, If the speculations
of some philosophers are accepted
mean great deal more. But before
anybody can have an adequate con-
cept of the cycle it is essential to
understand how Mr.. Kincer goes
about the job of calculation.
The normal temperature for Wash
ington is exactly SIS degrees above zero
Fahrenheit. This is established as
follows:
Every day the hourly thermometer
readings are added and divided by "a
The result is the mean temperature
for that day. Then the mean tenn
peratures of each day of the year are
added and the sum divided by 1865
Then the mean temperature OF SO
years are added and the sum divided
by so. -.
The thermometer would read SIS all
the time if there were no temperature
variations, such as come with the four
seasons and with night and day. So.
in computing the floating mean. the
first step is to represent SIS degrees
as a straight line.
Actually, Of course, the mercury sell
dom reads exactly SIS. There is hardly
such thing as normal day" On
many days in the Summer it remains
pretty consistently around 80. On
many days in the Winter it sinks
almost to zero. If the average for a
day is 80, the meteorologists subtract
SIS and get plus 25-the number Of
degrees above normal. If the average
is zero they set down a SIS, which
is the number Of degrees below normal
Then all the minuses and all the
oluses are added together and the
smaller subtracted from the greater
II the result is a plus figure for the
year, that year has been warmer than
normal. II 1t is a minus figure the
year has been colder than normal.
Over q span Of so years the two