ns indicated an elaborate modification of the standard Otis
safety device--itself a direct derivative of E. G. Otis' original.

If any one of the six hoisting cables broke or stretched unduly, or if
their tension slackened for any reason, powerful leaf springs were
released causing brake shoes to grip the rails. The essential feature of
the design was the car's arrest by friction between its grippers and the
rails so that the stopping action was gradual, not sudden as in the
elevator safety. During proof trials of the safety, made prior to the
fair's opening by cutting away a set of temporary hoisting cables, the
cabin would fall about 10 feet before being halted.

[Illustration: Figure 26.--Section through the Otis power cylinder.
(Adapted from Gustave Eiffel, _La Tour de Trois Cents Metres_, Paris,
1900, pl. 22.)]

[Illustration: Figure 27.--Details of the counterweight carriage in the
Otis system. (From Gustave Eiffel, _La Tour de Trois Cents Metres_, Paris,
1900, pl. 22{4}.)]

Although highly efficient and of unquestionable security, this safety
device was considered an insufficient safeguard by Eiffel, who, speaking
in the name of the Commission, demanded the application of a device known
as the rack and pinion safety that was used to some extent on European cog
railways. The commissioners not only considered this system more reliable
but felt that one of its features was a necessity: a device that
permitted the car to be lowered by hand, even after failure of all the
hoisting cables. The serious shortcomings of the rack and pinion were its
great noisiness and the limitation it imposed on hoisting speed. Both
disadvantages were due to the constant engagement of a pinion on the car
with a continuous rack set between the rails. The meeting ended in an
impasse, with Brown unwilling to approve the objectionable apparatus and
able only to return to New York and lay the matter before his company.

While Eiffel's attitude in the matter may appear highly unreasonable, it
must be said that during a subsequent meeting between Brown and
Koechlin, the French engineer implied that a mutual antagonism had
arisen between the Tower's creator and the Commission. Thus, since his own
judgment must have had little influence with the commissioners at that
time, Eiffel was compelled to specify what he well knew were excessive
safety provisions.

This decision placed Otis Brothers in a decidedly uncomfortable position,
at the m