Idaho County free press. [volume] (Grangeville, Idaho Territory) 1886-current, 1893-09-08
WEATHER DISSERTATIONS.

Description of the instruments
Used at the Agricultural
Experiment Station in
Idaho County.
A first-class set of meteorological
instruments has recently been re-
ceived at the Agricultural Expert
ment Station lat Grangeville, which,
when adjusted to uniform working
will make this a first-class station
of the Weather Bureau under the
Department of Agriculture. Pro-
badly month will be required to
get things in working order, when
weekly reports of the temperature
and rainfall will be published in
the FREE PRESS.
Observations of the Weather Blu
reau have a two-fold object-frst,
to obtain a knowledge of the eli
mate of region, e. the average of
the various air conditions over a
country that affect the health con-
veniences and comfort of the peo-
pie or influence plant growth;
2nd, the discovery and improve
ment of methods of predicting
changes in the weather. Observa-
tons over an extensive range of
country are used to trace the origin,
direction, and rate of progress and
temperature changes in the air,
the occurrence of rainfall, and the
direction and velocity of wind, dis
tribution of pressure and tempera-
ture over district.
The predictions of principal wea-
Their changes, even if only partially
successful, is sufficient motive for
the labor of making and preserving
the vast amount of weather Observ-
atoms now going on in most coun-
tries all over the world. Observa-
tions are desired in at least one
place in every county of every
State in the U. s. The observations
in which the Weather Bureau is
most interested are rainfall and
temperature. A trustworthy record
of the weather is always of interest
to any community, and often of
practical value. Farmers are in
terested in the season, whether
forward or backward, as regards
rainfall or temperature.
SOIL THERMOMETERS.
In an enclosure set apart for
meteorological instruments is a
weather vane which at present
changes it's pointing at least twelve
times an hour, the wind blowing
from all points within a short time.
A set of ten soil thermometers re-
cord the temperature of the soil at
depths of six, five, four, three, two
and one feet; nine, six and three
inches; and one inch, or the surface
of the ground. So far, the working
of the deeper thermometers is very
constant, $40 being the reading OF
the six feet one every day, while
those from two feet to the surface
vary from day to day.
MEAsURING THE RAINFALL.
A standard rain gauge has twice
had opportunities to show the rain
fall, once recording .0S of an inch
and next .06 of an inch. The rain
fall is received in a funnel-shaped
circular vessel and conducted below
into a brass tube one-tenth the di.
ameter of the upper funnel, the
reading showing on an ordinary
rule, one inch below, for every one
tenth inch of rainfall above, al
easy method of calculating. The
same instrument serves for snow
ten inches of fresh snow being
about equal to one inch Of rainfall
SOLAR RADIATION.
A solar radiation thermometel
is mercurial thermometer inclos
ed in a glass tube from which thu
air has been exhausted. They ar,
usually in pairs, one with a blacl
bulb, the other bright; both ar
exposed side by side in the sun
They are known as the bright an'
black bulb in vacuo. The blacl
bulb reads often 800 to 800 highe
than the temperature of the atmos
phere in the shade. The tempera
ture attained depends on the rat
at which heat is being receives
from the sun by the bulb and radi
ated to the Enclosure surroundin,
it. One is usually a maximum, re
cording the highest temperatur
during the day, the other mini
mum. The difference of brigh
and black shows the difference il
the heating effect of the sun on tn
air at different times. These in
struments are not yet adjusted.
DETERMINING MOISTURE.
The amount of moisture tina
exists in the air as vapor depend
ON the temperature. There is a Gel
tain pressure of vapor correspond
ing to every temperature, whic
cannot be exceeded; beyond thi
there is condensation. This ten
perature is called the dew poin
temperature of the air at that tim,
The less the quantity of mOistur
the air contains the lower will
the temperature of its dew poin