The Kenosha telegraph. [volume] (Kenosha, Wis.) 1860-1888, 1881-09-02
HUMIDITY OF THE Atmosphere.
How the Moisture in the Air Affects
our Comfort Under High Teafi-

VIC mercury db CU 10 90 Q05T0eSg This
IS the question asked by correspond
ent with an observing turn of mind.
We might reply to him briefly that The
thermometer does not tell all the story
as to the 'sbearability' of heat. Other
things come in to ameliofate OF to ac-
graFate the temperature-a breeze or
the Quantity Of moisture in the air.
. Relative humidity" however, as YOU
find In the weather reports; is the great
helper or the great offender. It is less
comfortable on hot moist day than on
hotter dry day.
The term "relative humidity" or
humidity" it is true, does not refer
to the absolute quantity of moisture in
the air. In the language Of meteorolo-
gists. the term humidity " denotes the
degree of its approach to saturation in
the cir (or containing as much as it can
hold. Il expresses the proportion
which the amount of vapor actually
present In the air bears to that amount
which the air would hold if it was at
the point OF saturation-when dew, mist
or rain is about to fall from it. When
the humidity is recorded IS 100, the air
IS completely saturated with Moisture
and rain is imminent, but if reported at
Is it contains only three-fourths of the
amount requisite for saturation.
1t is of great Importance for those
who would profit by the daily Signal
Service reports to bear In mind the sig
nlticance of its humidity column, es-
pecially IN the so-ealled "dog DAYS. .
The warmer the airis the larger becomes
the quantity Of invisible vapof it is ca
pable of sustaining and storing away in
the interstices between its atoms. At
the freezing point it can only hold one
hundredth part of its own weight of in
visible vapor at the temperature If SO
deg. the one-eightieth part Of its weight !;
at Sc deg. one-fortieth part, and for
every addition of ~ deg. Of temperature
its capacity is doubled. If fully satu-
rated at 80 deg. of temperature, it con-
tains 2.37 grains of aqueous vapor per
cubic foot at go deg, 5.87 grains in
each cubic foot, and at so deg. of the
thermometer, 1881 grains. A fall of
temperature from so to 60 deg. throws
down, therefore, nearly five grains of
water from every cubic foot of air thus
chilled. A cubic foot of saturated air
under average pressure and tempera-
ture of 80 deg. weighs 495 grains (Troy).
OF which 148 grains are pure aqueous
Vapor. With the temperature verging
on 100 deg, as it sometimes does in our
warm waves, +" the atmosphere &C satu-
ration contains as much as nineteen and
three-fourths grains of water to the cubic
foot, from which some idea may be
gathered of the enormous rainfall posi-
bilities of tropical clouds, which, heated
up directly under the fierce sun, arc re-
plete with the evaporation from equator
al seas.
At these watety PARTICLES offer resist
ance to the heat of both the earth and
air beneath them, which is seeking to
escape by radiation into the upper at
mosphere, they thus effectually prevent
the cooling Of the soil and of the lower
aerial strata. While the "relative hui
nudity" data in the Weather Bureaus
bulletins do not give the absolute
amount of vap0f in the air, neverthe-
less, when the percentages given are
high, or near 100, they show that the
molecules of vapor are coalescing over
head, and are forming with the air
atoms a canopy above us, which inter-
cepts the heat of the earth in it's at
tempt to fly into the clouds. The yapor
present also prevents the body from
throwing off its surplus heat. The abili-
ty Of the human frame to bear or throw
off the high cumulative temperature thus
engendered in our midsummer weather
depends upon several circumstances.
Evaporation from the skin and lungs is
perhaps the most important means the
body has of reducing it's surplus heat, as
DR.. Max Won Pettenkoffer, the eminent
Munich hygienist, has shown by the use
of an apparatus for testing the quantity
of water evaporated by men and ami
mails. His experience demonstrates
that men at rest evaporate about
two pounds only during twenty-four
hours, but on a day of hard work four
and half pounds of water. SIN the
first instance" he says, "about 2, DIG ca
loric units; in the second, 4, 480 had to
leave the body in consequence of evap-
oration," and he forcibly adds "This
explains how it can be that even with
the hardest work our blood will not
become warmer, but sometimes even
cooler, and what powerful means of
cooling our body we have in the increase
of our peripheric circulation and conse-
quent evaporation" Prof. Lortet, of
Lyons, while ascending Mont Blanc
found that the temperature in his mouth
and armpit was less than the normal,
and became normal when he was at rest
But the cooling effect of evaporation is
exhibited or. grand scale in the meteor
ology of the tropics. Last year, for in
stance, while in the high latitudes of
London and Boston the thermometer
reached or exceeded about 80 deg; at
the Island of Mauritius, lying in the
'steaming bosom of the Indian ocean,
within 20 deg. of the equator, the Their
mometer never once rose during the year
over $3.50 deg, and the register shows
that at the Island Of Barbados, IL deg.
from the equator, and in the hottest
part of the equatorial ocean, the maxi
mum temperature for the year was IS
deg. The greater GOODNESS of these
tropical islands was, of course, due to
the rapid evaporation of the equatorial
seas around them. and the fact demon
strates more palpably than even DR..
Won Pettenkoffer's costly apparatus
the hygienic value of evaporation for
the cooling of our body"
The BridegroOm's ''Best Man,
FThn 7o@n ~ 1J,o o.. =.