The mode of insulating the rails from each other is described by Bull as follows:—"Between the end of the rails, and also between the joint plates and rail ends, I insert a thin piece of leather, mill-board, gutta percha, or other suitable substance, suitable for cutting off metallic contact, and thereby insulate one rail of twenty feet, more or less, as may be necessary."
In Pope, in a description of his experiment at Charlestown, in a paper read by him before the New York Society of Practical Engineers—of which, by the way, Mr. Robinson was a charter member—and subsequently published, admits that he did not use the "rail circuit" at all in any proper sense of the term. On the contrary, he used line wires forming his main circuit terminating in short sections of rails, forty-two feet in length according to my recollection, that is, the length of one rail.
The train passing over the short rail section at one point closed the circuit through the line wires, thus exposing the signal, which was held in place by a "detent." The train, having reached a distant point, passed over another similar short section of rails, closing circuit through another magnet which released the "detent" and reversed the signal.
It will be observed that the essential features of the device used in Pope's experiment, on which he laid great stress, and described in Bull's patent, are identical, that is, the circuit closer consists, in the one case of a section of rails "twenty feet long, more or less," on open circuit, and the other identically the same, but with a rail section forty-two feet long, both using line wires.
Pope and his friends heralded this experiment—a revival of Bull's device—as demonstrating a wonderful invention on the part of Pope.
What Robinson Has Done in Automatic Electric Signaling
- He has created an epoch making invention of incalculable value to the human race in the wholesale saving of life and property on railroads, an invention of increasing importance and efficiency as time passes and its use is extended.
- It is an invention so unique and profoundly philosophical that those best skilled in the electrical art at the time it was made, declared that it was contrary to all known laws of electrical action and could not possibly work.
- Robinson's invention was not an improvement on something that preceded it. It had no precedent. It was an entirely new creation involving principles and methods of operation never before known or used by anybody.
- His invention was almost unique in this: It was a basic invention conceived, tested, put in practical operation in many installations, and perfected, as a system, in all its details, by its original inventor. He reduced it to its lowest terms and its highest efficiency, a perfection and efficiency of operation which have not been exceeded since it left his hands many years ago.
- His invention has made possible, with safety, the high speed railroading of today.
- As already stated, the automatic signal system used in and controlling the operation of traffic of the New York subway is purely and exclusively a Robinson system.
- Robinson's automatic signal system has increased the traffic capacity of the New York subway at least three-fold, and probably twice that. Without it the subway equipment could not transport with safety, one-fourth the number of passengers now carried.
- This invention has created a practically new industry, giving employment to many thousands of men, in various capacities, skilled and unskilled.
- It is enriching the railroads by enabling them to carry on twice the traffic, with a given equipment, that they could ever do before, and also by saving their equipment from destruction by collisions and other destructive means.
- The Robinson automatic system is admittedly the only signal system ever produced that meets all the requirements of safe and rapid railroading.
- Robinson's subsidiary invention of the rail bond, made more than fifty years ago in connection with his automatic system of signaling, and now in universal use on all electric roads using the track return, throughout the world, has made possible electric railroading as practiced today. Without this Robinson bond or its equivalent those electric roads using the track return could not be operated.
- The Robinson automatic system is a humanitarian invention of the very highest order, to which thousands of travelers by rail are indebted for the preservation of life and limb.
W. ROBINSON.
Improvement in Electric Signaling Apparatus for Railroads.
No. 130,661. Patented Aug 20, 1872.