The Scranton tribune. [volume] (Scranton, Pa.) 1891-1910, 1900-08-16

have been placed In position, ana
Scyanton is now a full-iicdged station
of the weather bureau.
Part OF the instruments on the roof
of the Connell Building can be seen
from the street. The iron pipe eX-
tending twenty-five feet above the
roof with a wind vane on the top, also
supports the thermometer that registers
the velocity of the wind, and the
four cups that are seen In perpetual
motion are turned by the wind, the
wind moving nearly three times as
fast as the cups.
Both the wind vane and thermometer
are conencted by an electric circuit
to the office on the fifth floor, where
the wind direction and movement are
registered.
The box supported on pillars on the
roof is the thermometer shelter in
which are five instruments for as
certaining the temperature Of the air.
The box has latticed sides that per-
NIT the free circulation of the air, and
q double roof, allowing the air to cir
culate between each roof.
one instrument in the thermometer
shelter registers the temperature on
a sheet of paper that Is placed around
a drum which is turned by clock
work. making q continuous record of
the temperature on the sheet, which
is so ruled as to indicate time as well
as the temperature line that the in
strument registers. This instrument
Is called n thermograph.
THE MAXIMUM.
Another instrument is the maxi
mum thermometer from the fact that
the mercury can rise, but owing to
q construction near the bulb, cannot
fall unless whirled, thereby showing
the highest temperature. The mini
mum thermometer has a very small
pin in the tube, the surface cohesion
of the alcohol in the stem drags back
the pin when the temperature falls,
but when the temperature rises, the
alcohol flows past the pin, which re-
mains at the lowest point the tempera-
ture fell from the time the thermome-
ter was set.
The humidity Of the cir is an fm-
portant factor in the effect of tenn
perature on the human system; in
summer q high humidity prevents
evaporation from the skin and conse-
quently the heat feels oppressive, for
if the humidity Is low, the moisture
of the skin is evaporated rapidly, and
as heat is used in the process of evap-
grafton, the temperature of the body
is lowered and one is cooled.
In winter when the air is damp,
the heat is conducted easily from the
body and a person will feel colder
with a temperature of thirty degrees
and a high humidity than with a
temperature of ten degrees and low
humidity.
Two thermometers are mounted on
an apparatus that can be whirled, one
thermometer has piece Of muslin
around the bulb; this muslin is dam
pened and then both thermometers
are whirled, and the dryer the air
the more rapid and completely the
muslin becomes dry. as heat is used
for drying the muslin, the drier the
muslin the more heat is used, and the
lower the mercury falls in the ther-
mometer that has the muslin around
the bulb, and if the air is very dry
the wet thermometer will be some
times thirty degrees lower than the
dry thermometer.
COMPUTING HUMIDITY.
From the difference in the readings
of the dry and wet thermometers the
amount of humidity is computed.
on the roof, exposed to the sun, Is
a thermometer with a very large black
bulb, the instrument being encaseC
in a glass case from which the all
has been exhausted. When the sur
is shining the black bulb OF the ther.
mometer absorbs the heat from the
sun more rapidly than 1t throws of
heat and therefore the mercury rises
higher than it otherwise would; wher
the mercury reaches a certain heigh
It becomes part of an electric cir
cult, which is broken until the mer,
curry is expanded by the sunshine.
This thermometer is called a sun
shine record, and when the sun is
shining the electric circuit is CLOSED
and the time the sun shines is re
corded.
The raln-guage consists of q meta
cylinder twenty-four inches high anC
eight inches in diameter, with an in
ner metal cylinder much smaller thar
the outside cylinder. If one inch o
rain falls, the water is conducted int,
the inner cylinder, where it will stanc
ten inches. The object of this is t
magnify very light rainfalls so that ;
measurement can be made; If for in
stance, the tenth Of an inch Of wate
was found in the inner cylinder, tn
rainfall would be registered as tn
hundredth part of an inch.
In the weather bureau Office is tn
apparatus for registering, by mean
of an electric circuit, the wind direc
tion and velocity, the rainfall and tn
duration Of sunshine, the instrument
themselves being, Of course, on tn
roof.
THE BAROMETER.
The barometer is located in the of
fee, and may be simply described a
consisting of glass tube about thirty
three inches long and about one-fourt
inch inside diameter. The tube /
closed at one end and filled with meT
curry, the open end of the tube, bein
closed firmly with the finger tip,
then submerged in an open cup c
mercury. Upon removing the finge
and causing the tube to stand ver
ucally, a portion of the mercury wi
pass from the tube into the cup, leaN
Ing a vacuOus space in the top OF I'll
tube. The column Of mercury remain
Ing in the tube WILL at sea level, /
about thirty inches, the weight of tn
mercury being sustained by and eS
actly balancing the downward pres
sure Of the air upon the surface
the mercury in the cup. The heigt
of such a mercurial column, therefor
becomes a measure of the pressul
of the air.