The Mankato free press. [volume] (Mankato, Blue Earth County, Minn.) 1879-1924, 1886-01-22
THE DUST.

THE WORLDS DUST.
What It Is, How 1t Is Made, and tho Man
ufacturers That Make 1t.
Where the dust comes from is often a
wonder to housekecpers. who find that,
no matter how carefully the house be
kept, the dust will accumulate as mys-
teriously as fluff in a vest pocket. A
visible way of accounting for the dust
on furniture is to trace il to the last
carpet sweeping. but this is only n of
the sources of house dust. 1t comes
from the ceilings. from the imperceptibly
slow disintegration of the walls, FROM
the decay of the furniture, from cloth
ing, from human bodies, from the plants
and trees outside, and even from be-
yond the orbit of the earth. so that a
portion of the dust upon q lady's piano
may have just arrived on the earth from
a distance of untold millions of miles.
Various estimates have been made of
the amount of m%e;eoric dust daily de-
posted on the earth by the meteors
which are necessarily arriving. and the
total, while relatively small. Is absolute
ly very large.
From dust TO dustmakers the transit
ton 10 easy and natural, Dust is merely
matter of any kind-mineral, animal.
or vegetable-in small particles and
dried, SO that it may be readily trans
ported by the wind from one point to
another. The two great dustmakers are
air and water. The action of the former
is exceedingly slow, SO that ages are re-
quired for the conversion of stone into
dust, but if time enough be allowed the
thing will be done. little by little the
particles Of the stone separating one
from another. until finally the disinte-
grafton by the action of the air alone
Is complete, and the bit Of flint or
granite is converted into a little heap OF
dust. But far more rapid is the disin-
tegration when the air Is aided by
water. Water is chemically a great
solvent, taking up a portion Of each
substance placed in it, or over which II
passes. This solid matter it seldom re-
tains as q permanent solution, but gen.
orally, by evaporation, deposits else.
where in a fine powder. which needs
only a little sun and wind to convert il
into dust,
Something more than three-ifths Of
the rain which falls over England and
Wales sinks into the ground and goes te
feed the springs from which, in dry
weather, except in the neighborhood O
snow-clad mountains, all brooks
streams, and rivers derive their whole
supply of water. and as these increas,
in volume the farther they flow, it il
evident that they must receive their sup
plies not only at their source, but a
various points along their course. TIL,
river Thurn, for instance, starts with {
flow of IL cubic feet of water PEI
minute; but a quarter of a mile from
the spring head, though it has not beer
joined by any visible tributary streams
the flow has increased to 81 cubic feet
at a distance of five miles and a half i
has increased again to 800 cubic feet
so that other, and perhaps many, small
springs must have been discharged int,
il. Now, all running water, whether l
flows above or below ground, has som
power of wearing away its channel
Flowing at the rate of about three niche
a second, it will remove fine clay; a
double this speed 1t will remove fin,
sand; at IL inches 1t will sweep ava,
fine gravel, and at 8 feet it will rol
along stones as big as an egg; Will
mountain torrents which have dwindle,
to mere threads, swell in a few hours t
such a size that they will carry befor
them sand and rocks, and trees, will
sweep away bridges, and bury meadow
ten or fifteen feet deep in rubbish
Then. again, a mere drlbble of waite
flowing perpetually over limestone rock
will, in time, produce results such a
seem quite out of proportion to its size
and we may in fact safely affirm tina
even the most sluggish stream wears it
bed more or less, in n way or another
either chemically or mechanically. ]
is by gravel and sand, though they loo
80 much less important than the bowld
ers, that the chief work is done; bu
much depends upon the inclination an
consequent rapidiiy of the current, a
well as upon the nature of the rock
with which it has to deal, Even
rivulet when flooded, will transpor
from 1000 to 5000 tons of gravel in
day, and during the rainy season in In
dia, when every river and mountain
torrent are swollen, when for days an,
nights together nothing is heard but tn
crash of trees and powders and grea
masses of earth and rock, 5000 to 400
feet in length, fall from the mountain
side and are ground to sand and mu'
in the boiling waters, the channel q
every stream, great and small, is en-
larged, and enormous quantities of min
eral matter are carried down to tn
ocean. One river in Bengal removes
depth OF ninety feet of stone and cart
from its bed every year, and the Gange
brings down in the same time more thal
enough solid material to build up forty
two great pyramids.
No small part of the worlds dust
made by the winters cold. A rain falls
the rocks are porous, and in every crac
and Granny the water penetrates, the
comes a cold spell, the water IN tn
rocks freezes, swelis with irresistibl
force, and in every direction O thousan'
tiny riffs are made, which are increase
in size and made more numerous b
subsequent winters until the solid roc
Is DiOWH away ny tie WiuuS, 1ldClcI
are wonderful agents for transporting
earth and stone from place to place, an
not only do they carry huge masses Q
matter about, but they also act a
grinders and polishers, thus converting
large quantities of the hardest stone
into fine dust. Icebergs also act in tn
same way and almost to the same ez
tent. Plants contribute to the formation
of dust by their power of disintegration
All plants require NOR o. less silica. j
their composition, and when the sui
stance of the plant is again resolved il
to its original constituents the result ]
silica in the dust. The vegetable acid
Of plants have also a solvent power o.
stone of any kind, so that if one spra
of moss or lichen can by any mean
grow on a surface Of bare granite, wher
not a trace of earth appears, it will 500
prepare the soil for others of the sam
kind, and no long time will elapse er
the solid rock is covered with a Twin
mantle of moss. Other plants, an
finally trees, worms, beetles, and bul
rowing animals contribute their shar
to pulverize the earth and reduce it a
to dust, bringing to the surface portion
of soil that never before saw the ligh
and leaving the sun, air and rain, to d
their work in the manufacture of th
worlds dust.-Sk. Louis Globe DemocrG