TELEVISION TODAY AND TOMORROW
By MAJOR A. G. CHURCH WHEN Bell introduced the telephone in 1876, the complementary notion- of sending vision by an electric current at once fired the imagination of scientific workers, and for a time much ingenuity and effort was expended on the attempt to add television to telephony. But the lack of any appreciable advance towards-the goal for many years led to the absorption of the more active workers in the new problems which arose in connexion with .the lucrative and more promising field of radio- telegraphy and telephony - •- - Actually it was fifty years after the ;transmission of speech by wire that John --Baird, the Scottish inventor; working with the crudest • materials in a tiny- room in Hastings, proved to his own satisfaction that he had successfully overcome the difficulties of sending recog- nizable images of persons through a cable or radio link to a distant place, and in January, 1926, before a group of scientific workers in London, he established his claim as the inventor of television, at the same time re-empha- sizing the fact that inventive genius lies in the capacity to select and bring to a focus on a problem those bits of the whole mass of knowledge which are indispensable to its solution. • Mr. Baird's success aroused world-wide interest, - and within a few months, after visits to his laboratories, the laboratories of most of the largest electrical manu- facturing concerns in the United States and in Germany were engaged in research on the development of the art, mainly with the object of being the first to develop its undoubted commercial possibilities. In America, where novelty has more appeal perhaps than in any other country, television receiving sets were soon being mar- keted, the different companies controlling American broadcasting stations vied with each other to provide television programmes, and television technical develop- ments and transmission and reception became the subject-matter of regular criticism in the Press.- In Germany the Government provided Baird with the use of the Witzleben station for a series of experinriental television broadcasts, following which the Reichspost, the German broadcasting authority, ' commenced sys- tematic research in television in its own laboratories, and called the principal German firms engaged in the radio industry to a conferenee to formulate a programme of co-operative television research and development. In addition, out of the - accumulated surplus from broad- casting licence fees, - the Reichspost has given- direct financial encouragement to certain firms for T the manu- facture of teleiision transmitting and receiving-apparatus, some of which is for the specific purpose of demonstrating the quality of German apparatus to -broadcasting authorities in other 'countries. - It • is difficult to say with certainty 'that • television transmission has advanced further -in- Great -Britaiir. and Germany than in Ameriea. The great American corn- . - . panics concerned with its development have so far successfully prevented representatives of rival concerns from witnessing demonstrations of their apparatus or from obtaining information regarding the results of their researches. A similar veil of secrecy shrouds the activi- - ties -of at least one important British concern interested in the commercial exploitation of television. This much is certain, however. One company in Great Britain- and one company in Germany are now in • a position to provide a service of " high-definition tele- vision " of real eptertainment value. The features and movements of speakers or of one or more artists in a studio, events of- the day or other film subject matter, and certain indoor and outdoor events can now be transmitted either instantaneously or within a few seconds (depending- on the subject matter) for clear and faithful reproduction in the home on a screen about a foot square, accompanied by sound 'on the same receiver.
Anyone who has " looked-in " at dne of the television broadcasts which have been a feature of B.B.C. pro- grammes for more than two years may doubt the truth of the above statement. It must be borne in mind, however, that the apparatus at present in use by the B.B.C. was provided by the Baird Company some years - ago and its design and construction were determined by the maximum side-band available for transmission, by broadcast stations. This limited the definition of the transmitted picture to 30-lines, that is to say, the division of the surface presented by the subject-matter. into 30 parallel strips. The recent revolution in tele- vision is not due to any departure from the principles originally enunciated by Baird. These are still the basis of all television methods. It is due mainly to the development of ultra-short wave technique, and the adaptation of the cathode-ray oscillograph to the recep- tion of television signals.
At one time it was believed impracticable to utilize ultra-short waves for broadcasting purposes, but recent researches have shown that they can travel through the ether without distortion or dissipation for more than twenty-five miles, and that disturbances due to low- frequency oscillations, such as those caused by the ignition system of a motor-car, can be easily eliminated. The cathode-ray oscillograph or " tube " has now superseded the mechanical forms of home-receiver,. because the electron, the motion of which is used to form the picture on a fluorescent screen, is the most easily controllable and -the lightest unit of all matter available, and - this makes synchronization of the transmitted and received picture a much more simple task. Up to the present the electron has been constrained to trace out -the picture on a fluorescent screen on the inside end-of the tube, and this -limits the size of the picture to - roughly - one foot- square: To provide :larger -*tures attempts are being made in, various laboratories to devise a tube in which a sufficiently bright image is formed for optical projection on an external screen: It is probable, however, that the first " high-definition television " transmission of current events on to a cinema screen will be by means of what is known technically as the " intermediate-film " system. By this method 'the subject-matter transmitted is received on an ordinary cinema-film, the film rapidly developed and- fixed and passed direct through a cinema projector, the whole process being continuous and occupying less than ten seconds. It will involve some years Of • investigation; however, before it can be hoped that the results obtained by this method will-compare favourably with the -quality - of pictures obtained by modern cinema-photography.
It must not be expected, even if the Postmaster- General's Committee on Television, which has just completed its task of investigation, reports that the art has reached a stage of development to justify the immediate inauguration of public television- broadcasts in this country,- that television will be available to the whole population within a -few months. To embrace the whole country within the range of television 'broad- casting stations will take time, the period depending On the amount of financial encouragement which either the Postmaster-General or 'the Government is prepared to afford for the erection of a sufficient number of ultra- short wave television transmitting stations and for the -provision of satisfactory programmes' at each station: At present it is only practicable to broadcast high-definition television to cover the London area. It is by no means certain that -these broadcasts -could be satisfactorily relayed by radio for transmission by other stations at a distance : but it is certain that they could not be relayed by cable like sound relays, for at present-there is ap- parently no cable capable of conducting such abnormally high frequency currents to any appreciable distance.
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