Wood County reporter. [volume] (Grand Rapids [i.e. Wisconsin Rapids], Wis.) 1857-1923, 1903-08-25
ADDRESS ON
THE WEATHER
DR.. Wilson Gave an Interesting
Address at Wisconsin Gram
berry Convention.
CLEAR STATEMENT OF
WEATHER CONDITIONS
Valuable Advice the to Gram
berry Growers and Citizens
i'm General.

Zone of the difficulties which con
fronts the practical cranberry grower
us set down by Mr.. White in his
excellent little work on cranberry
culture is the ever present possibility
OF partial or total loss Of crop by
the late spring or early fall froStS
Although the cranberry is a hardy
plant and indigenous to our rugged
northern climate, the comparatively
long period required for the maturity
OF the fruit renders it probably more
liable to injury from frosts than
most other varities of small fruit SO
that the cranberry grower is never
free from the apprehension of a
possible failure from the time return
ing spring first awakens the fruit bud
from it's winter sleep until the
matured fruit is finally gathered in
the fall. Notwithstanding the condi-
tion in some quarters that the
cranberry, like the persimmon, and
wild grape, is not fully matured and
properly favored until subjected to
the action of frost every grower knows
that frozen berries are not marketable
and however much a frost may i'm
prove their favor for certain palateS
for him frost means financial loss.
Most of the cranberry growers are
doubtless, more or less familiar with
these conditions having spent many
anxious nights on the marsh ObServ-
ing this phenomenon but it may be
well to refresh our minds briefly going
over the important steps in connection
with the formation of frost. The at
mosphere of the earth always contains
more or less moisture in an invisible
form. When at a considerable eleva-
tion above the earth this moisture, OF
aqueous vapor, is condensed, clouds
are formed; when the process Of con-
denSatiOn is more active and the
temperature of the air is above
freezing, rain falls; and when the
temperature of the air is below freez-
ing snow is produced. When the
moisture of the air in immediate
contact with the earth is condensed,
at temperatures above freezing, dew
is formed. When at temperatures
below freezing frost is deposited.
Frost is therefore, the moisture of
the air condensed at freezing temper
atures upon plants and other object
near the surface of the earth. No
frost is therefore possible until the
temperature of the surface has been
cooled to 81 degrees far.
'"There are two principal methods
by which parts lose their heat, viz:
Convection and radiation. COnvec-
tion is operative only when the
temperature of the air surrounding
the plant is lower than that of the
plant itself and is affective in produc-
ing frostS only on the sudden approach
of cold wave, in which the air has a
temperature of 81 degrees or lower.
1t is very rare indeed that damag-
ing frost occurs from this cause, for
on clear calm nights when trosts
mostly occur the surface Of the plants
is generally cooler than the surround
ing air. The chief methods then by
which plants lose their heat during a
clear, calm night is by radiation. By
radiation is meant, that peculiar
process by which heat escapes from
an object in direct lines in the same
way that the rays are emitted from a
source of light. Heat emitted from
an object by radiation, does not
appreciately warm the air through
which it passes, but becomes mani.
fest only when the passage of the heat
ray is obStructed by some object
Heat rays travel with almost inCon
ceivible velocity and those of you who
have watched your thermometer on q
frosty night when stray cloud passed
over, have seen how quickly the
steady fall in temperature was
checked and the thermometer ever
caused TO rise as the heat emitted by
radiation was reflected back from the
passing cloud. The process of radia
tion is in constant operation. During
the day plants usually receive more
heat from the sun than they give off
consequently grow warmer while al
night more heat is emitted thar
received, and their temperature falls
On clear nights this fall in tempera
ture usually continues until tn,
condensation of vapor begins, and it
continued until temperature of 8
degrees is reached when frost occurs
The vapor of water although invisible
is always present in varying quanti
ties in our atmosphere, and is th
most effective protection agains
frost. In fact, as remarked by Prof
Tyndell, many years ago, were th
vapor of water removed from ou
atmosphere for one single night, evel
in midsummer, it would be followe,
by frost that would surely destro