Figure 29. — Section through cabin of the Otis 

 elevator. Note the pivoted floor-sections. As 

 the car traveled, these floor-sections were 

 leveled by the operator to compensate for the 

 change of inclination; however, they were soon 

 removed because they interfered with the load- 

 ing and unloading of passengers. (From La 

 Nature, May 4, 1889, vol. 17, p. 3(30.) 



ing in a period before the Otis bid had been accepted, 

 were attempting to evolve an apparatus capable of 

 the complete service to the second platform. The use 

 of a rigid direct plunger thus precluded, it became 

 necessary to transpose the basic idea in order to adapt 

 it to the curvature of the Tower leg, and at the same 

 time retain its inherent quality of safety. Continuing 

 the conceptual sequence, the idea of a plunger made 

 in some manner flexible apparently suggested itself, 

 becoming the heart of the Roux machines. 



Here then was a design exhibiting strange contrast. 

 It was on the one hand completely novel, devised ex- 

 pressly for this trying service; yet on the other hand 

 it was derived from and fundamentally based on 

 a thoroughly traditional system. If nothing else, 

 it was safe beyond question. In Eiffel's own words, 



the Roux lifts "not only were safe, but appeared safe; 

 a most desirable feature in lifts traveling to such 

 heights and carrying the general public."'^ 



The system's shortcomings could hardly be more 

 evident. Friction resulting firom the more than 320 

 joints in the flexible pistons, each carrying two rollers, 

 plus that from the pitch chains must have been im- 

 mense. The noise created by such multiplicity of 

 parts can only be imagined. Capacity was equivalent 

 to that of the Otis system. About 100 people could be 

 carried in the double-deck cabin, some standing. 

 The speed, however, was only 200 feet per minute, 

 understandably low. 



If it had been the initial intention of the designers 

 to operate their cars to the second platform, they must 

 shortly have become aware of the impracticability 

 of this plan, caused by an inherent characteristic of 

 the apparatus. As long as the compressive force 

 acted along the longitudinal axis of the links, there 

 was no lateral resultant and the only load on the 

 small rollers was that due to the dead weight of the 

 link itself. However, if a curve had been introduced 

 in the guide channels to increase the incline of the 

 upper run, as done by Otis, the force on those links 

 traversing the bend would have been eccentric — 

 assuming the car to be in the upper section, above the 

 bend. The difference between the two sections 

 (based upon the Otis system) was 78°9' minus 54°35', 

 or 23°34', the tangent of which equals 0.436. Forty- 

 three percent of the unbalanced weight of the car and 

 load would then have borne upon the, say, 12 sets of 

 rollers on the curve. The immense frictional load thus 

 added to the entire system would certainly have made 

 it dismally inefficient, if not actually unworkable. 



In spite of Eiffel's public remarks regarding the 

 safety of the Roux machinery, in private he did not 

 trouble to conceal his doubts. Otis' representative, 

 Hall, discussing this toward the end of Brown's pre- 

 viously mentioned report, probably presented a fairly 

 accurate picture of the situation. His comments were 

 based on conversations with Eiffel and Koechlin: 



Mr. Gibson, Mr. Manning [who were other Otis employ- 

 ees] and myself came to the unanimous conclusion that Mr. 

 Eiffel had been forced to order those other machines, from 

 outside parties, against his own judgment: and that he was 

 very much in doubt as to their being a practical success — 

 and was, therefore, all the more anxious to put in our ma- 



'- From speech at annual summer meeting of Institution of 

 Mechanical Engineers, Paris, 1889. Quoted in Engineering, 

 July 5, 1889, vol. 48, p. 18. 



30 



BULLETIN 228: CONTRIBUTIONS FROM THE MUSEUM OF HISTORY AND TECHNOLOGY 



