1904.] on New Developments in Electric Railways. 467 



by the Institution of Electrical Engineers, when a three-phase 

 electric locomotive was shown in operation, which utilised currents 

 of a pressure of 10,000 volts and could attain a speed of sixty miles 

 per hour. 



This line was, however, only about a mile long, and the trials 

 were obviously not exhaustive enough to decide definitely how far 

 the electrical appliances in use were adapted for high speed traffic 

 on main lines. It served, all the same, the useful purjiose of settling 

 a practical form of conductor and of collector. 



The picture of the locomotive, as shown on the screen, was taken 

 when the president of the Imperial German Eailway Office and 

 Dr. Georg Siemens, director of the Deutsche Bank, visited the line 

 on the 29th March, 1900. 



Eventually it was decided to make experiments on a large scale 

 en the military railway between Marienfelde and Zossen, and with 

 a view of obtaining the co-oj)eration of all the most competent 

 engineers, a syndicate was formed, called " Studiengesellschaft fur 

 elektrische Schnellbahnen," by the Deutsche Bank, Delbriick Leo 

 & Co., National Bank, Jakob S. H. Stern, A, Borsig, Phil. Holzmann, 

 Friedr. Krupp, v. d. Zypen and Charlier, Allgemeine Elektricitiits 

 Gesellschaft, and Siemens and Halske. 



The military authorities placed the line at the disposal of the 

 syndicate, and the President of the Imperial German Eailway Office 

 became its chairman. 



While the problem was attacked in this fashion in the north of 

 Germany, Messrs. Brown, Boveri & Co., had opened in July 1899, 

 a service on the main line between Burgdorf and Thun, employing 

 three-phase currents of 16,000 volts, which are transformed to 750 

 volts for use in the motors. 



On the other side of the Alps, Messrs. Ganz & Co. fitted up the 

 Lecco-Sondrio railway with three-phase motors, in which their system 

 of " cascade " connection served for regulating the starting torque 

 of the motors. 



By this system the 3000-volt current of the line is connected 

 direct to the stator of the first motor, while the rotor of the first 

 motor is connected to the rotor of the second motor, both elec- 

 trically and mechanically ; while a resistance is introduced in the 

 circuit of the second stator. 



As the train accelerates this resistance is cut out until at half- 

 speed, the stator of the second motor is short circuited. The second 

 motor is then cut out altogether, and the resistance inserted into the 

 circuit of the first rotor ; again it is gradually diminished until at 

 full-speed the first rotor is short circuited. 



Just about two years ago Messrs. Mordey and Jenkin read a 

 paper on " Electric Traction on Railways," before the Institution of 

 Civil Engineers, here in London, and came to the conclusion that 

 a single-phase alternating current system was the best for the genera- 

 tion, transmission and distribution of power, with one overhead con- 



