The engineering profession, according to The Electrical World (New York), is the body of men who are to be congratulated on the achievement of television. Making use of principles already widely known, they have simply developed and devised machinery to make these effective, and have sensibly limited their efforts to a small field.
An engineering achievement
Demonstration of television was an engineering achievement of the first magnitude — one of which deserved the wide-spread acclaim brought to it by the popular nature of its appeal. Various experimenters in this field have in the past shown laboratory apparatus which it was hoped would some time produce vision at a distance.
The telephone engineers, avoiding premature announcements, have made their initial appearance in this field with surprisingly complete apparatus. With it they have actually demonstrated television in operation over hundreds of miles of intervening space.
Not content with its demonstration by a single medium of transmission, they have shown television both by wire and by radio. They have also developed several forms of receiving apparatus suited to the varying requirements of individual employment, such as would be needed in an ordinary telephone conversation, and to perception of the distant object by a considerable audience.
Inventors and prophets have envisioned it
It is noteworthy of television, as the telephone engineers have worked it out, that the solution follows closely the lines that inventors and prophets have visioned for at least a generation. The recent striking demonstration was not the result of any radically new discovery, but rather an achievement made possible by the general growth of science and technical contributions of a high order which have vastly extended the range of control of essential factors.
Such, for example, are the photoelectric cell, the distortionless vacuum-tube amplifier and the transmitting networks of predetermined characteristics, without which the ideas of a few decades ago, however sound, could not have borne fruit.
What the telephone engineers have done is to study intensively each element of the problem and apply to its solution the best means now available through modern science and engineering. It is an achievement of coordinated research and development of a kind possible only in a great research institution possessing facilities for the adequate study of every element of the problem.
In the case of television, these elements embrace everything from the details of terminal equipment, which can be studied in the laboratory, to a knowledge and control of the transmission characteristics of lines and radio channels.
Limitations of physical means
Another aspect of this achievement of particular interest to engineers is the nice balance which has been struck between the goal sought — in this case, the kind of scene which it has been chosen to transmit — and the limitations set by the physical means available. There has been much popular talk and discussion of transmitting such extended and complicated scenes as prize-fights, stage performances, and the like.
Anything as extensive and ambitious as this would require the transmission of an enormous band of frequencies far beyond the present capacity of a single pair of telephone wires or any radio channel now available. To transmit clearly such a relatively small and simple object as the human face requires a much narrower band of frequencies and one reasonably within the possibilities of present knowledge.
The fact that the peculiar problems of the telephone company are likely to be involved primarily with the adequate transmission of views of the human face makes its immediate television problem a simpler one than that which confronts those who seek to provide a distant vision of a pageant.
The AT&T television system
At the moment, the television system which the American Telephone & Telegraph Company has worked out utilizes substantially the entire available range of a high-class long-distance telephone circuit. As the demonstration showed, the rendering of the human face in animation is adequate, whether viewed in an individual apparatus or more than life size on a screen.
The avidity with which members of the audience, and even the telephone company officials themselves, utilized the transmitted image as an adjunct to their telephone conversations with Washington indicated very forcibly the probability that television must in the future be considered seriously as a desirable addition to existing communication services.
That it is ever likely to form part of the regular subscriber’s telephone equipment is hardly probable, since the element of distant vision is not required in the great majority of conversations. That a limited number of special television terminals may be provided in each large center of population for use in connection with long-distance telephony seems, however, quite within the range of present engineering and commercial possibilities.