The Anderson intelligencer. [volume] (Anderson Court House, S.C.) 1860-1914, 1881-01-20

ways sensible elevation Of the tomper-
ature of the atmosphere, due to the ev.
olution of latent heat. In. winter the
effect is more conspicuous and noticeable
than in summer, Tor se,chs which we
cannot in this place discuss. The cold,
clear dayc- of fWinter-vhoxoa recall
them | Y Now, LEI, us dpply this doctrine
TO the subject in hand. When aqueous
vapor is condensed ms dew upon plant
its latent heat is thrown out and warns
up the aiY immediately over The plant,
80 that the plant, TO get dew, must
be chilled, and IN getting dew is
warmed! In D this say, the period
of growth and ripening is protrac.
ted to later period in the fall than
would otherwise bs possible, and the
farmer ID softly admoniHhed of the ap-
preaching advent of winter.
Consider the tobacco 6eld--the broad,
bending leaves ripening in the mild Sop.
tember. Those Leaves, 70 become heavy
and oily, demand dew. To get dew,
they must be chilled; but if chilled too
sgauct, they ero ruined. 9As dglgia denq3.
5iPd ;3Rat i9 eyolvedinpot thsm. N91At
;c VG5drSua planl i Z ii aE3
The deposits Of dew are most abundant
exactly when it is most needed by vege-
tation. We have copious dew in April
and May, September and October, and
but little iu July and August. In April
and May. the seeds arc just sprouting. or
the roots at mort are bnt an inch or two
below the surface. A fsw hot, windy
days would dry the soil TO the roots end
below, and hence the young plants would
die from lack Of moisture. Every night
then, nature furnishes. the baby plants
with pap in the form of dew. The same
reasoning applies exactly to September
and October, when wheat and other veg
citation, that are to live through the win
ter, arc trying to get hold and bacome
securely anchored before cold weather
sets in. But, in July and August, the
roots have struck down six, twelve, cigh-
teen inches, TO the the regicu of perma-
nent moisture. They can live and thrive
for weeks now without rain for moisture
is stored away in the earth for their use
between the rains, and they are, to q
large extent, Independent OF the dew.
They get but little dew; they need but
little. i(
The philosophy Of dew formation ex-
t plains. clearly why dew is most abupdapt
exactly when it IL most needed. In May
or September, the days arc shorter and
cooler than in July. The earth at
sunset in these two months, is many de-
grees cooler than Mt sunset in midsum-
;mer. To sink to the dew point, there.
fore, 1t has to radiato into space less heat
and has, in the comparatively long night,
moro time to do 1t in. We have, there.
fore, tho heaviest deposits of dew in the
spring and fall. when it is most needed
because then less work is necessary to
produce the deposit aud more time is al.
lowed in the long nights for doing the
work.
Can we, to any extent, control the de.
pesit of dew7 Unquestionably, we can
When land is deeply plowed, the air,
striking down as far as the soil Is loosen.
ell, comes into contact with earth COO
enough to condeuae aqueous vapor. Thus
dew may be cnpiousiy deposited deeE
down among the rootlets Of plants, where
it is most needed, though none may bs
seen on tho surface of tho ohfiti. The
earth is very feeble conductor of heat
and hence is a,uch cooler, in summer
ten or twelve inces below than Mt thu
surface. The more deeply land is plowed
therefore, the more freely is air admitted
into the deep soil, where its aqueous va
pnr is condensed among tho rootlets, an,
left behind in the form Of dew.-Reii
gious Herald.