Page:Popular Science Monthly Volume 37.djvu/399

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on the other side are kept up to the proper tension. The compensation gear consists of a chain attached to the end of a rod, which here is not bolted to the saddle, and running down to a lever and weight beneath the track. These gears keep the tension of the rods uniform in spite of varying loads and temperature; on the line at Glynde the tension is two and a quarter tons. While this line was being constructed, Prof. Perry discovered that the tension of a rod could be determined very simply, by setting it to vibrating, and counting the vibrations in a quarter of a minute.

A train on the Glynde line consists of an electric locomotive and either five or ten skeps, in the latter case the locomotive being in the middle of the train. The skeps, are spaced evenly and somewhat widely apart, being connected by poles fourteen feet long, in order to distribute the weight of the loaded train over a considerable length of the rail, which allows the track to be light and correspondingly cheap, and in order also to have the train of the proper length to make the necessary electrical connections as it passes from span to span. The poles are attached to the buckets by a hook-and-eye coupling, easily detached. Each skep weighs one hundred and one pounds, and holds about two hundred and fifty pounds of dry clay. The cross-piece connecting the two wheels is of wood, so that the bucket, being suspended from this by a hanger, is insulated from the line, and may be handled without any shock being felt. An empty train at Glynde will travel to the clay-field where the track slopes down so as to bring the skeps nearly to the level of the ground. A laborer touches a key and stops the train, the skeps are then filled, the key is touched again, and the train starts off.

At the railway siding the train does not stop. The buckets pass above the middle of the cars, into which the clay is dumped automatically by the handle at the bottom of each bucket striking an arm projecting from a post. Any kind of a load, such as bags of grain or logs, may be hung from the hangers by replacing the buckets by bands, or a seat holding two passengers may be substituted for the bucket, which would allow of twenty passengers being drawn by one locomotive. For passenger lines, however, Prof. Perry says that it would be found probably more convenient to use a stiff rail rather than the flexible rod. A single-wheeled skep, suggested by Mr. Horace Darwin, has been given practical form by Mr. Gordon Wigan. A train of these skeps moves with less friction and is more flexible, so that it goes round curves more readily than a train of the two-wheeled skeps. Mr. Wigan has also designed a one-wheeled locomotive.

An end view of the "tandem locomotive," which is the form used at Glynde, is shown in Fig. 3.

This consists of a Reckenzaun motor, with the necessary gear-