The diamond drill. (Crystal Falls, Iron County, Mich.) 1887-1996, 1888-12-29

which covers the ground beneath the
forest Is OF considerable thickness.
On tho top II consists altogether Of
the dccaycd trunks, branches and
leaves. but IL shades downward into
ordinary dark-colorcd soil. at depth
of few feet from the surface. This.
the decay zone of the forest, lies be-
tween the boughs of the air and the
branches Of the roots. In IL 90 on the
most important actions which take
place I'm our forests-actions which af-
feet the history OF land and sea. We
shall therefore have To consider il I'm
somewhat painstaking way. The most
evident effect of this sheet of decay
ing wood and moss which feeds ON the
decay, Is on the rainfall Of the region
which il mantles. When, after a sea-
son Of drought, copious rain falls on
this spongy mass. the water Is for n
long time absorbed in the interstces
and does not How 10 the rivers. Even
i'm times of heavy rain the water is
slowly yielded 10 the streams; after a
dry period OF many weeks this sponge
retains a good share Of water. A like
amount of water falling on titled
fields or prairies slips quickly away TO
the rivers and thence to the sea. The
first result Is that when the land Is
destitute Of forests il sheds water like
house roofs. breeding ioods after every
considerable rain, while i'm the forests
the rain is only slowly yielded To the
streams.
A second and less evident result of
the spongy character of the forest bed
is that. by hindering the escape of the
rain-water To the rivers, IL Increases
the actual rainfall of the country. To
see the nature and Importance of this
action we must 7urn aside for mo-
mcnt TO consi ier the origin of the
rain which falls upon the land. The
original source of this water supply Is
the sea, which sends into the lands
tolerably regular supply annually OF
moisture. When this fails as rain or
snow. either of the two things may
happen--the water may 90 away di-
rectly TO the sea. or IL may return To-
the atmosphere as yapor. To be again
precipitated rs rain. The chance of
the Incorporation is determined by
the speed with which it flows TO the
streams. From trceless region IL
rapidly escapes; in an extensive region
of virgin forest IL may again and
again pass from earth to air. and from
air TO earth.
The columns Of vapor, which in
times of summer rain may be seen
ascending from every great wood, af-
ford visible evidence of the effect of
the forests on rainfall. They also may
show the observer some of the most
beautiful phenomena of atmospheric
circulation. In "A summer rain shower
the air above the trees becomes much
cooler than il is in the rccesses below
their tents of foliage. The heated air
within the woods seeks 10 rise and es-
cape in great columns whenever there
Is "a wide gap between the branches;
as soon rs IL attains the cooler level
above, the moisture is condensed, and
the air, before transparent, becomes
surcharged with steam. TO replace
this ascending air broad current
drifts toward the emerging stream of
vapor. commonly from the highest
parts Of the forest, where the air. ow-
ing 20 the elevation of the site, Is cooler
than in the lower levels.
The repeated passage of the moist
ure from earth 10 cloud and from cloud
I
Of force which the rain applies in its
falling drops Ia the earths surface:
but the rank vegetation protects the
surface from the erosion which it
would otherwise bring about. Even
the forest clad hillsides of the Cum
berland mountains where the soil lies
on decliyities of great steepness, suf-
fer little wear as long as their natural
protection Is left Ca them. But as
soon rs they are stripped of the gar.
ment of wood which has been upon
the region ever since, i'm the far off
ages, they came from the depths of
the sea. they wear with great rapid
ity. The erosion j. limited, as they
are forest clad. 90 the stream beds. aud
there Is hindercd by the innuniesable
obstacles of the fallen trees and en-
tangled driftwood. The brooks which
are strong enough To clear their beds
and cut into the earth and rock are
few i'm number; we may often, on the
hattcr ground. find tracts Of square
mile or SO in area in which there Is not
single stream that ever assails the
surface of the earth. As soon, how
ever. as the forest mat Is removed, the
surface becomes scanned with chan
nels; they often, on the deforcsted SUR
face, increase one hundred fold in
their length and more than that meas
nre In their destructive power. Re-
lieycd of all restraint from fallen tim
Der. of the close knit roots which i'm
mesh the earth. they sweep precious
s0il away toward the sea. In single
day titled field may lose from It's
surface more soil than would be taken