Figure i6. — English direct plunger hydraulic 

 elevator (about 1895). (From F. Dye, Popular 

 Engineering, London, 1895, P- 280.) 



in proportion to its loading. The direct-current 

 motor of the 1880's was easily capable of such service, 

 and it was widely used in this way. 



Adaptation of the motor to the direct drive of an 

 elevator machine was quite another matter, the 

 difficulties being largely those of control. At this 

 time the only practical means of starting a motor 

 under load was by introducing resistance into the 

 circuit and cutting it out in a series of steps as the 



speed picked up; precisely the method used to start 

 traction motors. In the early attempts to couple the 

 motor directly to the winding drum through worm 

 gearing, this "notching up" was transmitted to the 

 car as a jerlving motion, disagreeable to passengers and 

 hard on machinery. Furthermore, the controller 

 contacts had a short life because of the arcing which 

 resulted from heavy starting currents. In all, such 

 systems were unsatisfactory and generally unreliable, 

 and were held in disfavor by both elevator experts 

 and owners. 



There was, moreover, little inducement to over- 

 come the problem of control and other minor prob- 

 lems because of a more serious difficulty which had 



Figure 17. — Siemens' electric rack-climbing 

 elevator of 1880. (From Werner von Siemens, 

 Gesammelte Abhandlungen und Vortrdge, Berlin, 

 1881, pi. 5.) 



16 



BULLETIN 228: CONTRIBUTIONS FROM THE MUSEUM OF HISTORY AND TECHNOLOGY 



