eign materials" stipulation.
This exception is even more strange in view of Otis' futile request for
the same pumps and the fact that any number of native machines must have
been available. It is possible that Edoux's personal influence was
sufficient to overcome the authority of the regulation.

[Illustration: Figure 39.--Passengers changing cars on Edoux elevator at
intermediate platform. (From _La Nature_, May 4, 1889, vol. 17, p. 361.)]

[Illustration: Figure 40.--Worthington tandem compound steam pumps, at
base of the Tower's south pier, supplied water for the Edoux system. The
tank was at 896 feet, but suction was taken from the top of the cylinders
at 643 feet; therefore, the pumps worked against a head of only about 250
feet. (From _La Nature_, Oct. 5, 1889, vol. 17, p. 293.)]

[Illustration: Figure 41.--Recent view of lower car of the Edoux system,
showing slotted cylindrical guides that enclose the cables.]

Epilogue

In 1900, after the customary 11-year period, Paris again prepared for an
international exposition, about 5 years too early to take advantage of the
great progress made by the electric elevator. When the Roux machines, the
weakest element in the Eiffel Tower system, were replaced at this time, it
was by other hydraulics. Built by the well known French engineering
organization of Fives-Lilles, the new machines were the ultimate in power,
control, and general excellence of operation. As in the Otis system, the
cars ran all the way to the second platform.

The Fives-Lilles equipment reflected the advance of European elevator
engineering in this short time. The machines were rope-geared and
incorporated the elegant feature of self-leveling cabins which compensated
for the varying track inclination. For the 1900 fair, the Otis elevator in
the south pier was also removed and a wide stairway to the first platform
built in its place. In 1912, 25 years after Backmann's startling proposal
to use electricity for his system, the remaining Otis elevator was
replaced by a small electric one. This innovation was reluctantly
introduced solely for the purpose of accommodating visitors in the winter
when the hydraulic systems were shut down due to freezing weather. The
electric elevator had a short life, being removed in 1922 when the number
of winter visitors increased far beyond its capacity. However, the two
hydraulic systems were modified to operate in freezing
temperatures--presumably by the sim