SELENIUM CELLS, PHOTOELECTRICITY, AUTOMATIC MACHINES.) Perhaps the most valuable outcome of these endeavours will be the development of mechanisms capable of taking over those tasks that men and women find too monotonous or otherwise burden some. One such device is the Televox, invented in 1927 by R. J. Wensley of the Westinghouse Electric and Manufacturing Co. This device permits the use of the network of the telephone system for the distant control of an electrical mechanism by means of certain sounds. The mechanism is arranged to answer the tele phone and execute orders in a manner peculiarly similar to that of a human being. It was developed for the use of public utility companies to supplement the use of supervisory control sys tems of electrical sub-stations, reservoir systems, gas regulators, etc.
The Televox can transmit electric meter readings, heights of water, gas pressures, position of valves and switches, and can execute actual mechanical operations at the direction of a distant operator. In using the Televox a call is put through exactly as though there were a human operator on the other end of the phone. The person making the call uses certain tones of the desired pitch to transmit the message. It is essential that a consistency of pitch be maintained. These tones are ordinarily delivered by electrically driven tuning forks. The telephone transmitter converts the tones into electrical vibrations, which at the distant station are caused to actuate steel reeds, which in turn actuate the selecting and operating relays. The responses are obtained from an instrument
placed near the transmitter which sounds certain combinations of long and short notes, to form a code understandable by the opera tor at the other phone. The machine "hangs up" the receiver when the order has been executed, thereby ending the "conversa tion." There are a number of processing machines which control all processes in a given industry, including temperature and humidity control during the process, starting, stopping, and varying the different materials which enter into the process in accordance with a time schedule, and independent of an outlet. If anything goes wrong, the machine stops and shows a red light until the operator has made the necessary changes. At the conclusion of the opera tion the machine shows a green light until the operator has removed the material in process. The Tagliabue Automatic Flue Gas Analyzing Machine which makes an analysis for CO2 and for CO every minute, and records the results, is such a robot.
The Product Integraph (q.v.) is a robot which solves almost any second-order differential equation. It performs, by a com bination of electrical and mechanical means, certain compu tations which are actually beyond the power of the human brain, so far demonstrated. Other processes, which if performed by mathematics would require from a week to a year to solve, are solved by the integraph in a few minutes or hours.
(For New York City traffic control system see TRAFFIC AND