Figure 13. — Vertical cylinder, rope-geared hy- 

 draulic elevator with 2 : i gear ratio and rope 

 control (about 1880). For higher rises and 

 speeds, ratios of up to 10:1 were used, and the 

 endless rope was replaced by a lever. (Cour- 

 tesy of Otis Elevator Company.) 1^ 



possible with mechanical means. Cars with lever 

 control could be run at the high speeds required for 

 high buildings, yet they could be stopped with a 

 smoothness and precision unattainable earlier with 

 systems in which the valves were controlled by an 

 endless rope, worked by the operator. It was almost 

 completely silent, and when the cylinder was placed 

 vertically in a well near the shaft, practically no 

 valuable floor space was occupied. But most im- 

 portant, the length of rise was unlimited because no 

 drum was used. As greater rises were required, the 

 multiplication of the ropes and sheaves was simply 

 increased, raising the piston-car travel ratio and 

 permitting the cylinder to remain of manageable 

 length. The ratio was often as high as 10 or 12 to 1, 

 the car moving 10 or 12 feet to the piston's 1. 



In addition to its principal advantages, the hydraulic 

 elevator could be operated directly from municipal 

 water mains in the many cities where there was 

 sufficient pressure, thus eliminating a large investment 

 in tanks, pumps and boilers (fig. 14). 



By far the greatest development in this specialized 

 branch of mechanical engineering occurred in the 

 United States. The comparative position of Amer- 

 ican practice, which will be demonstrated farther on, 

 is indicated by the fact that Otis Brothers and other 

 large elevator concerns in the United States were able 

 to establish offices in many of the major cities of 

 Europe and compete very successfully with local firms 

 in spite of the higher costs due to shipment. This 

 also demonstrates the extent of error in the oft-heard 

 statement that the skyscraper was the direct result 

 of the elevator's invention. There is no question 

 that continued elevator improvement was an essential 

 factor in the rapid increase of building heights. 

 However, consideration of the situation in European 

 cities, where buildings of over 10 stories were (and 

 still are) rare in spite of the availability of similar 

 elevator techniques, points to the fundamental matter 

 of tradition. The European city simply did not 

 develop with the lack of judicial restraint which 

 characterized metropolitan growth in the United 

 States. The American tendency to confine mercantile 

 activity to the smallest possible area resulted in ex- 

 cessive land values, which drove buildings skvward. 



PAPER 19: ELEVATOR SYSTEMS OF THE EIFFEL TOWER 



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