TELPHERAGE 269 



This corresponds to 2'875d., or less than 3d. per ton per mile. 

 One very important feature in respect to the cost of telpher lines 

 is the fact that the larger part of that cost is due to plant, such 

 as locomotives, trains, and dynamos. This plant can be in- 

 creased in proportion to the work required ; thus there is a very 

 moderate increase of cost in the rate per mile for a small traffic 

 as compared with a large one, and, on the other hand, a line laid 

 down for a small traffic will accommodate a much larger traffic 

 with no fresh outlay on the line itself. 



There are numerous minor electrical problems involved, but 

 time does not permit me to enter into the consideration of these 

 to-night. It will be sufficient for electricians when I say that 

 I see my way to governing, blocking, and breaking the trains, 

 without ever interrupting the current used to work the motor, 

 except between the line and rolling wheels. We already know 

 that the interruption at this point, although accompanied by a 

 spark, does no injury whatever. I have often been asked whether 

 the frequent reversals involved in the cross-over system do not 

 tend either to injure the dynamo or the motor. I made special 

 experiments on this very point lately with a compound wound 

 Crompton dynamo and Mr. Reckenzaun's motor with thirty-six 

 coils. I was unable at the commutator of the motor to detect 

 the smallest change in the motion due to the most rapid reversal. 

 At the dynamo commutator I could just see when the reversal 

 occurred, but there was no change of a character to cause the 

 smallest alarm. At the same time I may state that, when from 

 any cause reversals may be thought undesirable, we are in pos- 

 session of apparatus which we call ' step-overs,' which, without 

 diminishing the simplicity of the permanent way, enable us to 

 send a continuous and nnreversed current. These and similar 

 electrical questions, such as the performance of Messrs. Ayrton 

 and Perry's excellent motors, might possibly have had greater 

 interest for electricians than some of the mechanical details dis- 

 cussed to-night ; but I have felt that the main point to establish, 

 in bringing this invention before the public, is that we have in 

 telpher lines a means of conveying goods in an economical manner, 

 by Hues, locomotives, trucks, dynamos, and motors, which have 

 undergone their preliminary trials with success, and can be at 

 once applied to the more searching test of performing work for the 



