The Rutland herald. [volume] (Rutland, Vt.) 1850-1852, 1850-07-11

I tJUuHtOSIs AWs>sbstss ossu NustStD WI
With their evcrvarying temperature
varying winds, and caoude, and con
s,snily changing humidity, arc al
results Of 6xed lAws, which inyi,h ID,
research ofcrery reasoning mind.
SoLAS IlxAr.-Aecording to Pro
fessor Forbes, tic rays ofhea. comm,
from the sun, and passing through th,
atmosphere 10 the sbortcs. line, a, The
latitude Of Paris, lose ej per cent. o.
their calori6c power by the time the,
reach tho earth. Rays that strik,
the atmosphere at an angle Of onl,
- deg. part with half their intensity
or heat, by the time they touch the
ground. The molecules Of air Absorb
and radiate heat into space, tho same
~ other pondorable bodies. Hence,
no matter how clear the atmosphere,
neither the rising nor the setting sup
imparts 50 much light or hca. to those
parts Of the earth SC affected as they
receive when the sun is at the merid.
ian. The effect Of solar rays on the
earth is still further diminished NOR.
ming and evening, by the fact ttat
fewer fal! on any given area, because
they impinge upon its surface obliquc.
ly. One can look at the setting sun
with impunity, not because il emits
less heat or light at that time, but
because the rays are mostly absorbed
and radiated in passing through many
miles Of atmosphere before they reach
the eye Of the observer.
The facility with which solar heat
penetrates and WARNS the soil, to the
depth Of q, II, Is, and ~, inches.
and the radiation of heat from the
earth, the leaves Of plants, and all
other substances, deserve particular
notice.
A distinction must bc made be.
tween the radiation of heat from the
surface ofany body, and The transmits.
sion Of it through any substance, as
non, wood, water, mold or soil. All
these hold different relations to this
peculiar element. 1t is not intended
to take more than popular view Of
this subject. At the time of seeding
in spring single day is sufficient to
warm to the depth Of 4 inches, a
mellow soil recently lloughed. Two
days Of sun will warm the ground 6
inches; and six days 12 inches
The fall Of warm rain Oh awcll drain
ed. mellow soil, greatly hasters the
heating Of the earth. On the con.
trary, the fall of a cold rain, or much
cold water in the ground, greatly re.
tards the rise of temperature in titled
land. Heat and water should be
studied together, if one would obtain
a clear idea of their JOINT influence on
vegetation. When water cvarorates
i, expands to ,G96 times its former
volume, and renders latent, or insen-
sible, q considerable amount Of active
heat. Hence, a wet piece Of ground,
from tho surface Of which a good
deal Of water cvaporatcs, is always
cooled by the constant loss Of scnsi.
bic heat which rises in vapor and de-
parts far into the atmosphere.
The warmer the atmosphere, the
greater is its capacity to hold water
in the condition Of a diffased invisible
vapor. The lower strata Of air are
heated much more by caloric radiated
from the Garth than by the apsorbtion
Of heat from the sun in its passage to
the plane. Air thus heated becomes
expanded or rarifed, and specifically
lighter than the colder air above it.
This causes the air within and near
the tropics to rise high above the sur.
face Of the earth, and flow over both
north and south, toward either pole i
while colder and heavier air rushes in
toward the equator to Gil the empty
sracc. These nrial currents are
detected in their courses by the
diurnal revolution Of the earth, and
by mountain ranges whose submits
arc often covered with eternal snow i
and they are still further modified by
the varying temp eraturc Of the ocean
and its peculiar streams.
Heat and water are the fruitful
parents Of winds and clouds. When
aqueous yapOr is rrecipi'ated in rain
or snow, heat that MAS latent becomes
again sensible, and by increasing the
capacity Of the air to hold water IN
the form Of vapor, prevents a disas-
trcus deluge Of this abundant elemen,
in nature. The laws which restrain
the precipitation Of water from the
clouds are no less curious than those
which cause it 10 rain at all. The
atmosphere mus. approach satura,ion
before it can rain and it usually
happens ,hS, the quantities which VII!
fxh on q given area, one hundred feet
above the ground, and On the earth
are unequal. Large drops. in falling
through many feet Of dry air, become
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