Fairhaven herald. [volume] (Fairhaven, Wash.) 1890-????, 1892-10-11
THE VALUE OF DUST.

Its Particles Form Free Surfaces for the
Collection of yapor.
How can invisible particles be brought
within the range of our vision? That
was one Of the first of the many marvel
Gus discoveries Of Mr.. John Astken, F.
K. S., Falkirk, a distinguished physicist,
whose remarkable work has revolution
lied a branch of meteorology. He
showed that without dust in the air
there could be no fogs, no mist, no cloud
and probably no rain. The particles Of
dust are the free surfaces, which, under
certain conditions, attract the water
yapor of the atmosphere to form fog.
Invisible before, they become visible
when clothed all over with the moisture;
unseen as dust, they become distinct as
fog particles.
This can be easily verified. If ordi-
nary air be forced through filter of
cotton wool into a glass receiver, it Is
deprived Of all its dust particles. Let
steam DO introduced into this receiver
from a boiler, no change will be OBJ
served; the vessel Is quite transparent.
But If jet of steam be introduced into
a similar vessel containing ordinary air,
1t will be seen rising in a dense cloud:
then beautiful fog viii be formed, so
dense that it cannot be seen through. In
the former case, when there was no
dust in suspension, the air remained
clear; IN the latter case, when the ordi-
nary atmospheric dust was in the YES
sci, fog at once appeared. The invisible
dust then is detected by the introduc-
ton Of water vapor.
Until very lately it was thought that
Particles of water vapor combined with
each other to form cloud particle, but
it is now found that some solid body,
however small, is required for this
formation. In fact, when there are no
dust particles on which the water vapor
at proper temperature and pressure
can condense, there is at present no
knowledge as to the point at which the !
change will take place. But the fine !
PARTICLES of dust in the air act as free |
surfaces on which the water vapor con-
denses into fog. When there is abund- |
ance Of dust in the air and little water |
vapor present there is an overpropor- |
ton of dust particles, and the fog par
ticles are in consequence closely packed, |
but light in form and small in size, and |
take the lighter appearance of fog. Ac-
if the dust is increased in the /
air, there is a proportionate increase of /
log.
But on the other hand if the dust
PARTICLES are fewer in proportion to the
number of molecules of water vapor,
Zach particle soon gets weighted, springs
INTO visible existence as if by creative
hand, and falls in mist or rain. If the
water vapor had no dust at all on which
% settle, it would use the objects on the
iurface of the ground for the same end.
IS the grass, leaves, tree branches or
house projections. Moisture would then
De ever dripping. The occasional genial
ain. though at times dashed up to a
biting storm of sleet, would require 10
i've place to constant wetness on the
Dads and grass
Umbrellas would not be needed, but
ndia rubber protectors for the feet and
egs would be in constant requisition.
Even the irritable housekeeper, ever an
loyed at the unaccountable appearance
# dust In rooms which she left for clean.
would prefer the old necessary evil in
his dry dust form than see the walls
tripping and the floor wet. = Good
Words.