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Show SIGNALS USED 111 STREET TRAFFIC (Special Dispatch.) Oakland. Cal., April 13. A street semaphore that is all but human has been Invented by J. G. Wallman of the Oakland police department. Chief of Police "Walter Petersen calls it the "last word in automatic devices for handling street traffic." Wallman's device is an electric semaphore. sem-aphore. New York used a semaphore system operated by hand levers by the traffic policemen, but there are disadvantages to this, as the policeman police-man must pay some attention to the levers and cannot devote all his at teniion to the traffic. The new electric semaphores are being installed at Twelfth and Broadway, Broad-way, Oakland's busiest corner, nntl will be given a thorough tryout. A semaphore arm is to be put at each of the four corners, thus controlling traffic in all directions and on both sides of the street The arms arc-controlled arc-controlled by four electric buttons, held by the "traffic policeman in the center" of the street. The current necessary Ib obtained from the regular regu-lar street lighting service. Each semaphore arm signals three ways visually, besides sounding an alarm. When traffic Is to be held up the arm Is horizontal and a sign reads "Stop," a red light being used for night signals. When traffic is allowed al-lowed to go forward on that side of the street, the arm drops and another an-other sign is shown or, at night, a green light. All this is done automatically auto-matically by a simple system of magnets mag-nets and Ib controlled by the pressure of a button by the policeman in the center of the streeL nn |