Observers who witnessed from day to day the construction of the great
Brooklyn Bridge were often heard to remark, as they looked up with awe
from the ferry-boats beneath at the workmen suspended everywhere among
the net-work of cables, "Those men look just like spiders in a web."
The comparison seemed irresistible, and the writer heard it expressed
many times. But how few who gave utterance to the sentiment realized
the full significance of the "spider" allusion, or for a moment
reflected that the span itself was, in many particulars of its
construction, but a parallel of an engineering feat of which the
spider was the earliest discoverer. Yet among all the distinguished
names engraved upon the memorial tablet upon the stone bridge-tower
the spider gets no credit.
Day after day and week after week we might have seen, travelling back
and forth against the sky, a wheel-shaped messenger reeling off its
tiny wire. Night and day it was busy, each trip adding one more strand
to the growing cable which was to support the great substructure
below. And what was this travelling wheel called? "The carrier," or
"traveller," if I remember rightly. Why this obviously intentional
slight and discourtesy when every field and wood and copse in the
country--indeed, on the globe--showed its living example, and bore its
myriadfold witness that the "spider" was the only legitimate and
proper designation?
In the other most notable suspension-bridge, at Niagara, the
time-honored methods of the spider were further and conspicuously
recognized, but here again without any courteous engraven
acknowledgment on the tablet of fame, so far as I have learned.
A kite was flown from the American shore, and reeled out so as to fall
upon the Canadian side, and this initial strand was drawn across, and
subsequently strengthened by the travelling reel.
The ends of the added wires were firmly secured at their anchorage,
and the completed cable at length re-enforced by guy-ropes.
What is the method of our spider? Ages before the advent of the human
engineer he followed the same tactics which we now see him performing
in every meadow, or even at our window-sill, or on the bouquet upon
our table, linking flower with flower, window-sill with garden fence,
bush with bush, tree with tree, with his glistening suspension-bridge
spanning the stream, river, and meadow. This wiry thread that tightens
across our face as we ride in our carriage, and leaves its tingling
"snap" upon our nose, what is this but the model suspension cable of
Arachne strengthened a hundredfold by the spider which has travelled
back and forth over its course for hours perhaps, each trip leaving a
fresh strand, one extremity being anchored on yonder oak in the meadow
and the other on the church steeple? Such a cable twenty feet in
length is a common challenge in our walks in the open wood road, even
making a perceptible motion among the leaves and bending twigs on
either side ere it yields to our advance. And to the walker who cares
to investigate, a silken bridge a hundred feet in length is not a very
exceptional find.
This bridge-building is not confined to any particular month or
season, nor to any one species of spider. The autumn will afford us
the best opportunity for observation. At that season the spider-egg
tufts are turning out their baby spiders by the millions, each a
perfect grown spider in miniature, and apparently as skilled at birth
in the peculiar arts of its kind as its parents were in their ripe old
age. Here is a troop of them upon this drooping branch of wild grape
by the river brink. Its leaves are glistening in the loose, rambling
tangle which marks their wanderings. They are evidently not satisfied
with their present surroundings, and would seem desirous of getting as
far as possible from the neighborhood of their cradle and
swaddling-clothes. They are the most independent and self-reliant
babies on record. They ask advice from no one--indeed their mother
died a year ago, perhaps--but each determines to leave his brothers
and sisters, to "see the world" for himself, and paddle his own canoe.
Fancy a first trial trip on a tight-rope from the torch of the Statue
of Liberty to Governor's Island! Yet such is the corresponding feat
accomplished by this self-reliant acrobat, which a few days or perhaps
hours ago was but an egg!
Here is one family of spiderlings upon the grape-vine spray, for
instance. They are hanging several yards above the water, and with an
ocean, as it were, between them and the distant country upon which
their hearts are set. But there is no hesitation or misgiving. Let us
closely observe this eager youngster far out upon the point of the
leaf. The breeze is blowing across the brook. In an instant, upon
reaching the edge of the leaf, the spiderling has thrown up the tip of
its body, and a tiny, glistening stream is seen to pour out from its
group of spinnerets. Farther and farther it floats, waving across the
water like a pennant. Two, three, five, ten, fifteen feet are now seen
glistening in the sun. Now it floats in among the herbage upon the
opposite bank, and seems reaching out for a foothold. In a minute more
its tip has brushed against a tall group of asters, and clings fast,
the loose span sagging in the breeze, and as we turn our attention to
the spider, we see that he has turned about, and is now "hauling in
the slack," which he continues to do until the span is taut, when he
anchors it firmly to the leaf, and without a moment's ceremony steps
out upon his tight-rope, and makes the "trial trip" across the
abyss--a feat which Dr. McCook, the spider specialist and historian,
has most felicitously compared to the similar trial trip of Engineer
Farrington across the cable of the East River Bridge, a thrilling
event which was witnessed by thousands of spectators from sailing
craft and housetops.
Our spider has now reached the asters twenty feet away, and is
doubtless busying himself by further securing the anchorage at this
terminus. It is quickly done, for see, he is even now far out over the
water on his return trip, arriving at the grape leaf a moment later.
His strand is now three times as strong as at first, and will be many
times stronger before he is satisfied with it. An hour later, if we
care to go up-stream half a mile to the bridge, or half a mile below
to the crossing pole, for the sake of examining those asters across
the brook, we shall find our spiderling nicely settled in a tiny
little home of his own. The glistening span is now like a tough silken
thread, and is moored to the head of flowers by a half-dozen
guy-threads in all directions, while in their midst, in the "nave of
his tiny wheel of lace," our smart young baby rests from his labors.
Such is the probable course which he would follow, unless, perhaps,
his roving spirit, thus tempted, has further asserted itself, and not
content with this exploit, he has concluded to span the clouds, and
is even now sailing a thousand feet aloft in his "balloon."
As a bridge-builder he has had many successful imitators, but as a
balloonist he is yet more than a match for his bigger copyist, _homo
sapiens_, as I shall explain in a subsequent paper.