The Iola register. [volume] (Iola, Allen County, Kansas) 1875-1902, 1896-03-13
U. S. WEATHER BUREAU.
Some Interesting aud Instructive Obser
vations About the Objects 1t Seeks
and the Work 1t Does,
BY CLARENCE J. NORTON.
PART XII,


air with regard to the amount of in
visible vapor it contains. Pour colo
water in glass, and in summer, the
outside surface will soon become
covered with condensed moisture
This moisture has not oozed through
the glass, but is the deposit of the in,
visible vapor in the air surrounding
it. In winter, the same will occur in
rooms where many persons are
assembled. The moisture from their
lungs and bodies will be condensed
on the glass Ofthe windows by the out
side cold. The temperature of the
surface upon which condensation be-
gins, is called the dew point.
The amount of vapor actually pre-
sent in the atmosphere is called the
absolute humidity. This divided by
the amount of vapor that might exist
were the atmosphere fully satured,
giver a ratio that is called the relative
humidity.
An amount of vapor sufficient to
cause high relative humidity at a
low temperature of the atmo sphere,
would cause only low relative
humidity at high temperature. An
amount of vapor that is sufficient to
produce only about % per cent rela-
tive humidity at a temperature of 80
degrees, suftices to fully saturate the
air when its temperature falls to
about 40 degrees. With given alb
solute humidity, the relative humid
ity will fall as the temperature rises,
and vice versa; as the air warns dur
ing the morning the relative humid
ity falls, but towards sunset, when
the air couls, the relative humidity
rises again.
When the air is cooling from noon
day heat to evening cool, its capacity
for vapor is constantly decreasing. At
noontime the amount of vapor present
seldom satisfies the capacity, and the
air then commonly has with us a re-
lative humidity of so to so per cent;
but with the afternoon fall of tempera-
ture and decrease of capacity, the
vapOr present approaches and finally
reaches the stage of saturation; the
temperature is then said to have fallen
to the dew point. Any further cooling
will cause condensation and produce
cloud, fog, dew or frost.
Any condensation occurring above
temperature of 80 degrees will, of
course, produce rain or dew, but if
below the freezing point, will produce
ice in the form of frost, hail or snow,
hence we sometimes say it is too cold
to rain. The average percentage of
moisture of the air is from go to 40 per
cent. If the air has less moisture than
60 per cent, it tried to avoid thorough
saturatiOn and gets rid of the mos
ture by condensation.
There is no element or condition of
the atmosphere which exercises such
a strong control over our bodily sensa-
ton of the temperature of the air as
humidity. The d florence in humidity
in Kansas and in the far north in
winter, corresponds to the difference
in mean temperature, or in other
words damp cold wind is more try
ing to the human system, that cold
dry one is.
Our bodies do not act like thermC-
meter, which readily adapts itself to
the temperature of the air immediate
ely surrounding, but our bodies en-
deavOr to maintain an even "blood |
heat' temperature at all times and |
under all conditions of health. This |
is about 50 degrees, and /
it is most remarkable what slight |
there are under the extreme |
under which the human |
race exists. In the Arctic regions the |
inhabitants have been known to en- |
dure temperatures as low as 80 degrees |
below zero; while in the tropics an air
in the shade of 120 de-
grees is not infrequent. The lowest
ever recorded on the |
earth's surface was that in Siberia |
January Is, 1885 at the town of /
when the thermometer
indicated 80 degrees below zero; the
highest temperature ever recorded
was 124 degrees above zero in Algeria.
Africa. July Il, 1879. The extreme
range as recorded for the United States
IS from 81 degrees below zero, in win
Ter in North Dakota. to ia degrees
above zero in summer in Arizona.
We therefore see the human race
existing under a range of tempera-
.ure amounting to 2l0 degrees, which
would be impossible were it not for
he all-wise provisions of nature
which tempers by never varying laws
he amount of humidity present.
We prevent an uncomfortable re-