TELPHERAGE IN PRACTICAL USE. 



387 



locomotive may be seen in Fig. 3, under the motor. While 

 ascending a steep grade the current will be on for almost the 

 whole time ; while descending* such a grade it will be off alto- 

 gether ; on level stretches it may be on for, say, a quarter of the 

 whole time of running. This plan avoids all waste in switches or 

 interposed resistances, and the current cut off by each governor is 

 too small to injure the dynamo. 



But since a train when going down a steep incline is liable to 

 get up too great a speed, even without its motor receiving any 





,v / ; w' 



Fig. 4.— Electrical Governor. 



electricity, the locomotive is provided also with a brake, shown 

 in Fig. 5. This is placed on the shaft of the motor, and the edge 

 of it may be seen in Fig. 3, beside the cog-wheel A. In Fig. 5, 

 W W are two weights whose centrifugal force, up to a speed of 

 eighteen hundred revolutions of the shaft A per minute, is bal- 

 anced by the springs S S, but above that speed the weights draw 

 outward and press the wooden brake-blocks B B against the metal 

 ring C, which is fixed to the frame of the locomotive, thus retard- 

 ing the motion of the train. 



The method of working telpher trains employed at Glynde is 

 what the inventors call the " Cross-over Parallel System." Fig. 6 

 is a diagram showing the electrical connections according to this 

 system, where an up and a down track are used. Each track is 

 divided into sections, each span of the ordinary length being a 

 section. Alternate sections of each track, A b B 2 , A 3 , B 4 , etc., are 

 electrically connected together and to one pole of the generator 

 of electricity D ; the other sections are also connected together, 

 and to the other pole of the generator. The two sets are well in- 

 sulated from each other. Only two wheels of a train are employed 



