It will be observed that certain of these sections are the same as above reproduced from the circular of 1870. It will be noted also that the description of the system begun after the heading is not here completed, for the reason that a full description is found elsewhere in this history. ROBINSON'S IMPROVED SYSTEMS OF ELECTRIC RAILWAY SIGNALS For Switches, Draw-bridges, Crossings, Curves, Cuts, and Tunnels; also, to indicate the Location, Direction, Rapidity, and Length of Trains. IMPORTANT IMPROVEMENTS.--ELECTRIC SIGNALING WITHOUT TRACK INSTRUMENTS, OR LINE WIRES. THE NEW SYSTEM. The operation of this system is as follows: A railroad track is divided into sections of any desired length, say one mile, more or less, by separating the abutting rails from metallic contact with the adjacent sections, but preserving metallic continuity throughout the length of the section. The insulation of the abutting rails is accomplished CURVE AND TUNNEL SIGNALS. A train approaching a curve throws up a red signal around the curve, as a warning to trains from the opposite direction, and also exhibits a signal in its rear. Thus, collisions from front or rear are guarded against. These signals may be used throughout the whole extent of a road. In entering a tunnel a train exhibits a signal at the other end to indicate its entry, and when it gets through it exhibits a signal at the opposite end to indicate its exit. STATION SIGNALS. A train when it leaves a station, and at various points as it passes, indicates to the stations along the line, its Location, Direction, Rapidity, and Length. Thus all necessary information regarding moving trains is automatically announced every few minutes at the stations. The batteries for operating the signals will last for months without attention, and one man can readily attend to all the signals and batteries throughout the whole extent of a road. In all cases, where practicable, the signal wire should be carried through the coils of a bell-magnet in the nearest office. By this means the operator is informed when the battery power is decreasing, and warned that it requires renewing. Office connections can be made, when desired, so that the signals may be operated by a telegraph key from the office, as well as by passing trains.