14 



NA TURE 



l^Mov. 5, 1885 



marked the final result of the experiences gained by the 

 constructors under the direction of Prof. Perry, and the 

 Company are now regularly delivering clay at the Glynde 

 Railway Station for the use of the Newhaven Cement 

 Company at a price, as we are informed, of 'i\d. per ton. 



The garlanded train which passed along the steel rod- 

 way on Saturday consisted of an electric locomotive, seen 

 in" Fig. I at about the middle of the train and propelled by 

 the electromotor M, and ten skeps, or buckets, which hang 

 by their travelling wheels from the steel line. Each skep 

 weighs loi lbs., and carries 250 to 300 lbs. of dry clay, 

 and, by distributing these evenly and somewhat widely 



apart, the strain on the steel line is small although the 

 total weight of the train and clay is about two tons, also 

 as equal weights are simultaneously ascending and de- 

 scending similar inclines on the several spans the effect 

 of the sag on the mechanical resistance of the train is 

 neutralised, and little more resistance is experienced than 

 in hauling a similar train along a rigid road. The rate of 

 travelling is 4 to 5 miles an hour about two electric horse- 

 power only being necessary to be furnished at the engine- 

 house to propel the train at this speed, and the train is 

 under the control of a workman, who, by touching a key, 

 can start, stop, or reverse the train at pleasure. On the 

 arrival of each telpher train at the railway siding the 



H 



\l 



clay is emptied into the railway waggons bytthe skeps 

 being tipped over, this being effected either by a man 

 touching with a pole the handles which are seen in Fig. i 

 hanging down from the skeps, or automatically by these 

 handles coming successively into contact with a wooden 

 arm padded with india-rubber which is made to stand 

 out from the post where it is desired the clay is to be 

 emptied. One train will deliver the minimum amount of 

 clay (150 tons per week) required by the Cement Company, 

 but, if necessary, twenty trains can be run on the line 

 without fear of a collision as an absolute automatic block 

 is provided, and the trains are, moreover, governed auto- 

 matically so as to run up or down an incline at the same 

 speed. 



This automatic governing of the speed of the train is 

 effected in two ways — first, there is a governor attached 

 to each motor, which interrupts the electric circuit, and 

 cuts off the power when the speed becomes too high ; 

 secondly, there is a brake which is brought into action 

 should the speed attain a still higher value. To avoid 

 the formation of a permanent electric arc when the circuit 

 is broken, the governor (Fig. i) is so arranged that the 

 diverging weights are in unstable equilibrium between 

 two stops — they fly out at about r/oo revolutions per 

 minute of the motor, and fly back at about i6ao. When 

 the circuit is closed the current is conveyed across the 

 metallic contact at C. When the weights \v w fly out this 

 contact is first broken, but no spark occurs because a 

 connection of small resistance is continued at B between 

 the piece of carbon and a piece of steel, which being 

 pressed out by a spring follows the carbon for a short 

 distance as the arm A begins to fly out. This contact is 

 next broken, producing an electric arc, which however is 

 instantly extinguished by the lever A flying out to the 

 dotted position. The brake is shown on Fig. 3, and con- 

 sists simply of a pair of weights, WW, which at a limiting 

 speed greater than 1700 revolutions per minute of the 

 motor press the brake blocks B B against the rim C C, and 

 introduce the necessary amount of retarding friction. In 

 practice, however, with the gradients such as exist at 

 Glynde, and which do not exceed i in 13, the economic 

 method of automatically cutting off the power with the 

 governor is all that is necessary to control the speed of 

 the train ; the brake rarely coming into action. With 

 steeper gradients, however, the brake would undoubtedly 

 be very useful. 



The current required is 8 amperes per train, this 

 current being measured by an ammeter in the engine- 

 house, and by roughly timing the intervals when no current 

 is being given to a train, that is, when the governor is acting, 

 the particular hill the train is descending can be electrically 

 determined by practice, and so the progress of a train 



^-=- 



-Af-©_ 



~J7W 





along the telpher line can be approximately followed by 

 simply watching the ammeter in the engine-house. The 

 electric current is supplied from a 200-volt dynamo driven 

 by a steam-engine, and controlled by a Willans electric 

 governor which automatically varies the speed of the 

 engine and dynamo so as always to keep the electro- 

 motive force at 200 volts whatever be the number of 

 trains -running ; hence the starting or stopping, of one 

 telpher train in no way affects the speed of the remainder. 

 It is obvious that water-power or any other source of 

 power can be used where available, even when the 

 source of power is at a considerable distance from the 

 line. By means of compensating gear the tension of the 



line is so regulated that it can never exceed actons on 

 each rod, whatever the temperature, and for straining the 

 steel rods, when first erected, up to the right tension an 

 ingenious arrangement has been devised during the con- 

 struction of the line of vibrating them and determining 

 the strain on a rod from the number of vibrations it 

 makes per minute. 



The way in which a single wheel track is made to serve 

 for one train, or rather two wheel tracks for two trains, 

 instead of the necessity of having four wheel tracks for 

 two trains, as in the ordinary electric railways, is seen 

 from Fig. 4. D is the dynamo maintaining two long con- 

 ductors permanently at different potentials indicated by 



