Shenandoah herald. [volume] (Woodstock, Va.) 1865-1974, 1885-11-20

is converted into ice with immense
activity. 1t is certain that, in tue
conversion of matter from a fluid
into solid state on 50 colossal a
scale, the quantity OF heat thus in
fused in a sensible form into tbe
atmosphere must exert very pow
erfll influence upon the state of
the air in countries bordering on
these cold regions, and it is only
necessary TO concede that the winds
from the North prevail at this per-
iod to make it conclusive that this
heat must increase the warmth of
this zone at this season Of the year.
There il a continuous tide of
heated air rising from the Torrid
zone, aud flowing north and sou tn.
During t1e season o. congelaiioo
in the Arctic zone there is like
wise a iie of beated air risiOg from
the North Polar sea, and flowing
towards TIE TOrrid zone. These
two currents meet about midway
in the Temperate zone, near the
forty.ffth PARALLEL of north lati-
tude, and in the collision the warm
condensed current in some measure
descends. This affords q solution
in some measure Of the warmth, as
we'll as of the calmness, the sOfr-
ness, and the dryness Of the air Of
Indian summer
1t is to be noted that these alleg.
ed inuhences, or either of them,
might produce a rise of the tenn
perature in the late autumn, but
neither of them could be credited
with the creation of the smoky
condition Of the atmosphere and
the redness OF the sky at this sea.
son, while the undoubted fact that
Indian SIMMER occurs with less re-
gularity than formerly is left to he
accounted for upon some other by.
pothesis.
An equally ingenious theory is
found in that exquisite volume,
Tue Woods and By.Ways of New
England, by Wilson Flagg. We
quote at length the views OF this
close and loving student of nature.
The Indian summer, If such a
season was ever known, was a phe-
nomenon produced by some M
explained circumstances attending
the universal wooded state OF he
country that existed for many years
after its settlement. 1t has been
observed that a meadow covered
with luxuriant grass and other
herbage cools the atmosphere that
rest upon it much more rapidly
than similar meadow covered
with a scanty berbage. The mos
ture exhaled into the air by vege-
table perspiration is greater than
from any other natural sOrface ;
and as the rad d'atiOn of heat is rap.
id in proportion to the moist con-
dition Of the atmosphere, the cool
ing process over n grassy meadow
IS vastly greater than over a slml-
lar ground bare of vegetation. A
wood, in like manner, by exhallng
through its foliage the moisture it
draws from the earth, cools the
atmosphere in proportion To the
amount o! its faliaee, while at tue
same time it shades the ground
from the sun. Anything that
should check this vegetable per
spiration would in the same ,aliO
preserve the heat OF the Amos
phere by diminishing the radiation
of beat that takes place more slow
ly in dry than in MOST aic.
This is precisely what rappens
soon alter the first severe frosts OF
November, when the whole exteDl
of the forest over thousands oI
miles is laid bare IN the brief space
of two or three days. There is
sudden and universal dimlnution
of The moisture that was given out
from the caves of trees and ouhel
plants before the frost had destroy
cd them; for the evaporation caus-
cd by the drying of fallen leaves
, and herbage Is comparatively slight
and ceases after a few hours ex
posure to the sun. The atmOs
phere being dry, and the radiation
eff heat proportioually small il
quantity, all these circumstances. /
no unusual atmospheric dlsturban
ces occur from any other hiddeI
, cause, unite in producing sud
, den aud uni, ersal accumulation o
heat. The warm period that fol
l lows is the Indian summer.
Il can easily believe that, befor
p. the encroachments upon the Amer
- lean forest were very extensive
J. this balcyon period of autum ma
n have occurred every year wit
y great regularity. But, since th
!. clearing is almost universal, thes
}. conditions have been entirel