hine was installed by Otis in a
Chicago theatre. As the name implies, the cables were not wrapped on a
drum but passed, from the car, over a grooved sheave directly on the motor
shaft, the other ends being attached to the counterweights. The result was
a system of beautiful simplicity, capable of any rise and speed with no
proportionate increase in the number or size of its parts, and free from
any possibility of car or weights being drawn into the machinery. This
system is still the only one used for rises of over 100 feet or so. By the
time of its introduction, motor controls had been improved to the point of
complete practicability.

[9] Mechanical transmission of power by wire rope was a well developed
practice at this time, involving in many instances high powers and
distances up to a mile. To attempt this system in the Eiffel Tower,
crowded with structural work, machinery and people, was another matter.

[10] According to Otis Elevator Company, the final price, because of
extras, was $30,000.

[11] In _Pall Mall Gazette_, as quoted in _The Engineering and Building
Record and the Sanitary Engineer_, May 25, 1889, vol. 19, p. 345.

[12] From speech at annual summer meeting of Institution of Mechanical
Engineers, Paris, 1889. Quoted in _Engineering_, July 5, 1889, vol. 48, p.
18.

[13] Located near the Tower, built for the Paris fair of 1878.

[14] Improved oil-well drilling techniques were influential in the intense
but short burst of popularity enjoyed by direct plunger systems in the
United States between 1899 and 1910. In New York, many such systems of
200-foot rise, and one of 380 feet, were installed.

[15] An obvious question arises here: What prevents a plunger 200 or 300
feet long and no more than 16 inches in diameter from buckling under its
compressive loading? The answer is simply that most of this length is not
in compression but in tension. The Edoux rams, when fully extended,
virtually hung from the upper car, sustained by the weight of 500 feet of
cable on the other side of the sheaves. As the upper car descended this
effect diminished, but as the rams moved back into the cylinders their
unsupported length was correspondingly reduced.

[16] M. A. Ansaloni, "The Lifts in the Eiffel Tower," quoted in
_Engineering_, July 5, 1889, vol. 48, p. 23. The strength of steel when
drawn into wire is increased tremendously. Breaking stresses of 140,000
p.s.i. were not particularly high at the time. Special