studied it becomes increasingly difficult to imagine 

 by what qualifications he was regarded as either an 

 elevator expert or designer by Eiffel and the Com- 

 mission. His proposals appear, with one exception, 

 to have been decidedly retrogressive, and, further, to 

 incorporate the most undesirable features of those 

 earlier systems he chose to borrow from. Nothing 

 has been discovered regarding his work, if any, on 

 elevators for the lower section of the Tower. Realiz- 

 ing the difficulty of this aspect of the problem, he may 

 not have attempted its solution, and confined his work 

 to the upper half where the structure permitted a 

 straight, vertical run. 



The Backmann design for the upper elevators was 

 based upon a principle which had been attractive to 

 many inventors in the mid-1 9th century period of ele- 

 vator development — that of "screwing the car up" 

 by means of a threaded element and a nut, either of 

 which might be rotated and the other remain station- 

 ary. The analogy to a nut and bolt made the scheme 

 an obvious one at that early time, but its inherent 

 complexity soon became equally evident and it never 

 achieved practical success. Backmann projected two 

 cylindrical cars that traveled in parallel shafts and 

 balanced one another from opposite ends of common 

 cables that passed over a sheave in the upperworks. 

 Around the inside of each shaft extended a spiral 



Figure Q2. — Various levels of the Eiffel Towei 

 (Adapted from Gustave Eiffel, La 

 Trois Cents Metres, Paris, igoo, pi. i.) 



PAPER 19: ELEVATOR SYSTEMS OF THE EIFFEL TOWER 



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