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| AXLE OF THE FERRIS WHEEL - As the principle of the
Ferris Wheel was tension in its lower spokes, the upper spokes
hanging on the arch that was supported by the lower spokes, it
followed that the axle of the wheel must be of uncommon size,
integrity and strength. To be certain that his wheel would not fall,
Mr. Ferris made this axle large enough and strong enough to bear a
burden six times as great as the weight of the cantilever bridge
across the Ohio River at Cincinnati, which structure is computed to
weigh about as much as the Ferris Wheel. With an axis six times as
stout as he might need, the mechanician was safe to proceed, for he
has had a wholesome fear of accident, realizing that one bad disaster
at the beginning would destroy all hopes of financial success. Two
men and a boy, under the big hammer at Bethlehem, the model of which
was a central feature of the Transportation Building, forged the
piece of hammered steel, and it arrived safely at Chicago and was
handled in the coldest weather. The shaft was solid, and forty-five
feet long; it was thirty-two inches in diameter, and weighed as much
as a heavy locomotive - that is seventy tons. It was and is the
heaviest piece of steel ever forged - certainly outside of Krupp's
works at Essen. It is seen in the engraving as it began its ascent
to the sockets that were to receive it on top of the towers, one
hundred and forty feet upward, and after it was in place the hubs
that catch all the tension spokes were fitted to hold their burden of
two thousand tons. |
