Evening star. [volume] (Washington, D.C.) 1854-1972, 1931-08-13

A spider so small as to be almost
invisible has taken up his home on q
weather glass, and proceeded to spin
himself a neat web.
When he was observed, by the luckiest
chance, being so small, the strictest
orders we're given to leave him alone,
with the result that he has been there
about month.
His web grows larger and larger, fuller
and fuller, until a portion Of it is al
most fabric.
He has grown perhaps one one-hun-
dredth of an inch in that time. but is
still so small that his legs are scarcely
visible.
He is perhaps the smallest spider in
captivity.
The functioning of the weather glass,
a large pear-shape closed at the top,
with a spout somewhat resembling that
of a teapot, in no way worries the
spider
The action of the glass depends on
the relative pressure of the atmosphere
in comparison with the body of con-
fined air in the top of the bell, sealed
in by the lake Of water, which rises
or descends in the spout
AS the air outside grows heavier, its
pressure on the top of the water in
the spout forces the column down and
back into the bell. This signifies clear
ing weather.
AS the outside air grows less dense,
it relieves the pressure on the water,
and thus the impounded air, which
remains stable pushes the column
higher and higher in the spout, spill
ing over at the approach Of wet
weather.
Comparison of this rise and fall with
that of the hand in an aneroid barom-
eter shows that the water Is down
at the bottom Of the spout when the
pressure is 80 40 plus, and that it rises
rapidly as the hand Of the aneroid in
strument begins to go backward, be-
ginning TO come out of the spout when
the hand of the other instrument
reaches the neighborhood Of 80 inches.
These figures mean no more to the
miniature spider than they may 10 the
reader here who has never made 1t
his pleasure to compare these two
types Of barometerS.
The spider does not mind the drip
OF water from the tip of the spout. He
spins his web serene, causing the large
bell to shiver slightly on its support.
1t Is a curious fact that after the
water has been rising out of the spout
for some time, dripping drop by drop
down the outside, to spill on the bit OF
blotting paper below, it drops suddenly,
perhaps as much as a half-tnch just
before the storm breaks.
This change, dramatic one In lit
tie, no doubt comes about as result
OF the wind which usually precedes q
thunderstorm. But the spider does not
mind it all in the least. He Is utterly
unconscious that he is part of any
sort of instrument.
No doubt what he likes about the
glass is the bright glistening character
Of the bowl, and the long spout, which
gives him perfect place for web con-
struction.
Not only has he tied the entire yes
sci to its stand by tenuous strands,
but he has weaved back and forth be-
tween the spout and the glass itself.
So far the insect has been very
fortunate.
Never once, so far as we know. has
he happened to be down on the blot
ter just before a storm.
Down on the blotter. that Is, at the
precise point where the drops fan.
II he were. he would be pink spider,
for the water has been colored by the
simple procedure Of dropping in flve or
six drops of red ink, the red ink dear