Southport telegraph. [volume] (Southport, W.T. [i.e. Kenosha, Wis.]) 1840-1850, 1847-06-02
THE INFLUENCE OF TREES IN PRODU.
CHG RAIN.

The Boston Chronotype at the close of article IN
regard to the importance of cultvating the sugar
maple, has the following
"But if they 1.-THE farnnersl look to their own and
their posteritys good, they will not cut down all
their trees at any rate Already northern ONO SUI
fers terribly almost every summer in the shape OF
severe droughts for the too great havoc which has
been made of its trees fit keeps on, flat as 1t is,
in exterminating its forests it will be little better
than Sahara. 1t is only billy and high rolling
countries that can do without trees, and they must
suffer much"
The idea suggested by this paragraph is an i'm
portant one To make the matter plan, however,
to the mass of readers it may be necessary to adj
vert to some principles in natural philosophy.
l. The condensation of vapor is effected by
body of atmosphere meeting with other bodies cold
er than itself The extent to which this process is
carried on may be in some measure apprehended II
we turn ou1 thoughts to the magnificent scale OF its
operation in mountainous districts of country. One
yard of elevation brings lis to change OF climate
equal to what we find in advancing distance OF one
mile in latitude--100 yards of elevation change
of temperature equal TO what is found in 100 miles
Of latitude-1OOO yards Of elevation equal to what
is found in 1000 miles Of latitude-and so on. For
instance, we live north of the equator almost 5000
miles. and have the climate which is found on the
sides of mountains in Brazil at an elevation of 5000
wards, or little less than mile and half five
were to 90 north Of the equator about 5000 miles,
we should reach the latitude of the northern por-
tions of Greenland, climate not habltabe by man.
A climate equally severe nearly so, is met with
upon the SUBMITS Of those peaks of the Andes
which rise as high five thousand yards, or three
miles Thus the region Of perpetual frost is reach
ed even at the equator by ascending to the heighth
of few thousand yards. Hence, lofty mountain
ranges are continually condensng the yapor Of the
atmosphere, and to an extent sufficient to supply
the water OF the rivers that necessarily flowing
from them Take for Illustration the condensation
of vapor upon the outside Of pitcher or jar, filled
with we'll or ice water in warm atmosphere.
What that phenomenon is on very small scale,
the mountain condenser is on scale of stupendous
magnitude and what that phenomenon is for very
brief space of time, the other is perpetualy and IN
| terminaby What the jar of cold water Is IN one
case, and what the mountain is in the other case a
tree or forest also is according to its heighth and
the extent of surface it presents to the atmosphere
If a lar of cold water will condense quantity OF
vapor sufficient for an of water in the space
of half an hour large oak, with its Wide-spreadng
top. might condense to the amount of many gallons
in night. and an extensive forest might form mil
lions of tons of water every night from an atmo
sphere which would have parted with none of its
vapor had the same locality been prairie cultiva
ted ground instead of forest We do not forget that
considerable time, frequently several hours. must
eapse after night fall at the close of hot day, be-
fore the trees become cold enough to act as con
densers Several other particulars Of subordinate
importance might be noticed, but the principle is
perhaps sufficiently exhibited.
? Trees of the forest very commonly become
the conductors for the streams ELECTRICITY that
passing in the atmosphere. Discharges of eectri-
city uniformly condense the vapor the atmosphere
in the vicinity of their occurrence. Thus, thunder
showers are much more frequent and abundant in
forest regions, as a general fact, than in regions
without forests,
8 OF the quantity OF vapor condensed, and rain
that falls the portion carried off by evaporation is
vastly less in forest country than IN country
destitute of forests. Hence the increased dryness
of SOIL and the dimnuton in quantity or disappear
ance of springs and streams of water consequent on
the clearing up of timbered country
4. In the summer season. or during that portion
of the year when the country is most liable to suf-
fer from drought, the existence of vastly greater
quantities of moisture within the forest districts
and the influence of forest vegetation in lowering
the temperature of the atmosphere give to that dis
trct much lower temperature than it would 9th
erwse have In extremely hot weather, yapor is
often condensed and clouds and rain are formed at
an elevation so great above the earth as that the
rain is changed to vapor again before it reaches the
surface The height at which condensation takes
place in the atmosphere and the improbahity of
the rain reaching the earth in its descent. will be
greater or less accordingly the atmosphere in that
locality is more or less heated and consequently
the chances for forest district to be refreshed by
showers in hot weather are greater in proportion as
the height at which condensation takes place and
the heat OF the atmosphere IN those localities, are
less
There is one important consideration which pro-
baby the Chronotype did not take into the account
in speaking OF the present and prospective dryness
of the climate in northern Ohio, and that is the Vi
cinity of Lake Erie, which, in supplying moisture
and preserving low temperature, a stale of at
mosphere favorable to rain, is for aught we know,
even better than equal extent of forest The
neIghborhood of Lake Michigan to the country inn
medately about it of course answers the same pur-
! pose.
We have no wish to drive any of our prairie
dwellers those remote from the lake, into the TIM
Der, or to impeach the wisdom OF their choice in
pretering prairie to tmbered district, but what we
had in view and what we wish particularly to in
lOf ha