Page:Popular Science Monthly Volume 37.djvu/403

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Fig. 7 shows how the ends of the steel rods are fastened and insulated from each other. The end of one rod is turned down and fastened to the cast-iron saddle with a nut, as shown at the right of the figure. The end of the next rod, A, is bolted to the cast-steel cap C, which is insulated from the saddle by an insulator of vulcanite, V; and, in order that the tension of the rods may not break the vulcanite, melted lead is run in between the

PSM V37 D403 Ordinary saddle.jpg
Fig. 7.—Ordinary Saddle.

saddle and the insulator, and between the insulator and the cap. To prevent the metallic wheels of the skeps from short-circuiting the two sections as they cross the tops of the posts, there are insulated gap-pieces, as shown in this figure, on the saddles between each rod and the next.

Each of the motors at Glynde receives a power of about fifteen hundred watts, or about two horse-power, and as the potential is about two hundred volts everywhere on the line, each motor receives about eight ampères when a train is running at about four and a half miles an hour. The dynamo used on this line is a Crompton six-unit "shunt-wound" machine of the Gramme type driven by a steam-engine. It is evident that a telpher line could be run with water-power, where this is available, even if the source of power is several miles from the track.

The line at Glynde is a little under a mile in length. On long lines it is expected that a source of power would be needed every ten miles, working the trains for five miles in each direction.

The advantages claimed for telpher lines over surface railroads using steam locomotives are, first, the much less cost of the road and equipment. Thus, as the result of the experience gained in constructing the Glynde line, it was estimated that a similar line could be erected for a total cost equal to about six thousand dollars, including engine, dynamo, track, and five trains, with