The Dawson news. (Dawson, Ga.) 1889-current, 1906-06-06
GREAT STRENGTH OF SPIDER
1~CECTS DO ENGINEERING FEATS
THAT ARE MARVELLOUS.
They Also Lift Mice and Snakes, and
Do other Things That Seem
Almost Human.


One of the most interesting books in
natural history is work on 'Insect
rchitecture," by Rennie. But if the
architecture of insect homes is won
derful the engineering displayed by
these creatures is equally marvellous.
Long before man had thought of the
saw the saw fly had used the same
tool. made after the same fashion and
used in the same way for the purpose
of making Sits in the branches OF
trees so that she might have a secure
pIace in which to deposit her eggs.
The carpenter bee, with only the
tools which nature has given her, cuts
a round hole, the full diameter of her
body, through thick boards, and SO
makes a tunnel by which she can have
a safe retreat in which to rear her
Young. The sexton beetle will in a
few hours bury beneath the ground
the carcass of a comparatively large
animal.
All these feats require a degree of in
stinct which in a reasoning creature
would be called engineering skill, but
none of them are as wonderful as the
feats performed by the spider. This
extraordinary little animal has the
faculty of propelling her threads di-
rectly against the wind, and by means
of her slender cords she can haul up
and suspend bodies which are many
times her own weight.
Spider Hangs Mouse in Midair.
Some years ago a paragraph went
the rounds of the papers in which 1t
was said that spider had suspended
an unfortunate mouse, raising it up
from the GROUND, and leaving it to
perish miserably between heaven and
earth. WOuld-be philosophers made
great fun of the statement and ridi-
culed it numerically. 81 know not
how true it was" says Rennie, "but
[ know that it might have been true.
Some years ago, in the village OF
Havana, in the state of New York, a
spider entangled milk snake in her
threads and actually raised it some
distance from the ground, and this,
too, in spite of the struggles of the
reptile, which was alive.
''By what process of engineering
did this comparatively small and
feeble insect succeed in overcoming
and lifting up by mechanical means
the mouse or the snake? The solution
is easy enough if we only give the
question little thought.
''The spider is furnished with one
of the most efficient mechanical nipple
ments known to ngineers-namely a
strong elastic thread. That the thread
is strong Isl we'll known. Indeed,
there are few substances that will sup
port greater strain than the silk of
the silkwOm or the spider, careful
experiment having shown that for
equal sizes the strength of these fbers
exceed that of common iron. But,
Notwithstanding its strength, the
SPIDERS thread would be useless as a
mechanical power were it not for its
elasticity.
What A ChiIG Can Do.
'"The spider has no blocks or pull
levs and, therefore, it can not cause
the thread to divide up and run in
di fferent directions, but the elasticity
of the thread more than makes up for
this and renders possible the lifting
of an animal much heavier than a
mouse or a snake. This may require
little explanation.
''Let US suppose that child can
lift six pound weight foot high
and do this twenty times a minute.
Furnish him with $50 rubber bands,
each capable of pulling six pounds
through one foot when stretched. Let
these bands be attached to a wooden
platform on which stands a pair of
horses weighing 100 pounds, or
rather more than ton. If now the
child will 90 to work and stretch these
rubber bands, singlv, hooking each
one up as it is stretched, in less than
twenty minutes he will have raised
the pair of horses one foot.
"We thus see that the elasticity OF
the rubber bands enables the child to
divide the weight of the horses into
$50 pieces of six pounds each and at
the rate of a little less than one every
three seconds he lifts all these separ-
ate pieces one foot, SO that the child
easily lifts this enormous weight
Engineering Feat Explained.
Each spiders thread acts like one
of the elastic bands. Let US suppose
that the mouse or snake weighed half
an ounce and that each thread is ca
pable of supporting a grain and a
half. The spider would have to con-
meet the mouse with the point from
which it was to be suspended with $50
threads, and if the little quadruped
was once swung off its feet it would
be powerless. BY pulling successive
ly on each thread and shortening it a
little the mouse or snake might be
raised to any height within the capac-
ity of the building or structure in
which the work was done. SO that to
those who have ridiculed the story we
NAV Justly say: There are moro
things in heaven and earth than are
dreamed of in your philosophy.
"What object the spider could have
had in its work | am unable to see. 1t
NAV bova baoo 9ppa5 OF tho h nm