Note: The following is a research paper written in Spring, 1995 for Dr. James Mulholland's "History of Technology" (HI 341) course at North Carolina State University. It has been sitting there in a filing cabinet for years, and while writing the "brief history of TV" portion of the "Uncle Looney Show" page I thought "why not use this, after all it's written already." Because of when it was written, there's no information regarding the development of digital television which became the standard in June, 2009. Perhaps one day this will be added. In the meantime, this will at least give anyone who is interested an idea of how it all evolved through the days of Uncle Looney and a bit beyond.

Television is a powerful medium which brings the sights and sounds of the world into the homes of nearly everyone. The television process seemed to emerge overnight in post World War II America, but it actually began in the 1800's with the three unrelated discoveries of persistence of vision, the facsimile machine, and the photoelectric nature of certain metals. Its evolution included multi-channel, mechanical, and electronic scanning systems. Here I will follow the histories of the three television systems from those early discoveries to the beginning of "TV's Golden Years" on April 13, 1952.

P. M. Roget studied and wrote about persistence of vision in 1824, twenty-eight years before he published his thesaurus. (Photo courtesy of Royal Institution of Great Britain)

Television and its sister, the movies, were concurrently born with the study of persistence of vision. This marvel was first examined by the English mathematician P. M. Roget in 1824. He showed that two different pictures on opposite sides of a card appeared to occupy the same space at the same time when the card was rapidly flipped back and forth. Belgium's J. A. Plateau went one step further in 1832 when he invented the phenakistoscope--a device which animated a series of pictures.

Another important forerunner of television was the facsimile machine. A "picture telegraph," as it was called, was first proposed by England's Alexander Bain in 1842. Though unsuccessful, it "included the principles of single-channel transmission, sequential scanning, and synchronization." All are fundamentals of today's television process. Frederick Bakewell improved the design in 1847 in London. Meanwhile, Italian priest Abbe Caselli patented a similar successful machine in England in 1861. It was later used in France, sponsored by Napoleon III.

The most essential prerequisite of television was the discovery of a photo-conductive substance. In 1873, Joseph May, an Irish telegraph operator, noticed that instruments made of selenium behaved strangely when the sun was shining on them. He found that the resistance of that metal varied with the amount of light shining on it. Five years later, the Frenchman Constantin M. Senlecq proposed his "telectroscope," a facsimile machine which moved a piece of selenium over a picture. His later designs included mosaics of tiny selenium cells, which scanned pictures as the cells were activated in succession.

Paul Nipkow designed the first successful television scanning device in 1884. John L. Baird built a system that worked (as well as that idea would ever work) in the 1920s.

Scientists realized that with a device utilizing selenium cells, a picture or even a moving image might be dissected into tiny elements and sent to a distant receiver. In 1879 Denis D. Redmond transmitted "a luminous image by electricity" with his "electric telescope," which employed "a number of circuits...containing selenium and platinum" modeled after the human eye. George Carey of Boston suggested a system using a transmitter consisting of a mosaic of selenium squares which were individually wired to corresponding lights in a receiver. The next year, John Perry and William Ayrton suggested using a lens to focus the image onto the light-sensitive mosaic.

The first successful television scanning device was designed by German engineer Paul A. Nipkow in 1884. His system employed a scanning disk with a spiral pattern of holes punched in it, which was placed before a brightly lighted picture. As it revolved, the first hole crossed the picture at the top, the second hole a little lower down, and so on. With each revolution the entire picture was briefly exposed, in turn, to the beam of light shining through the holes. Selenium photocells placed around the picture measured the light reflected from it and generated a continuous electrical signal of varying strength. The receiver included "a high-intensity light source, the brightness of which would be modulated by the strength of the current from the transmitter's photocell" which passed through a similar revolving disk and was "projected on a screen." The two synchronized disks turned fifteen times per second--just fast enough to achieve persistence of vision.

This diagram shows how the Nipkow / Baird system worked. The diagram fails to show how the person on the receiving end had to keep one hand on a "speed adjustment" knob, constantly tweaking it, to keep the rotating disk on the home receiver synchronized with the one in the TV studio. (Original diagram courtesy of PBS; cat photo courtesy of Visual Dictionary Online).

Although Nipkow never constructed a device based on his design, others began experimenting with it. In 1884, Jean Weiller proposed replacing the disk with a "rolling drum" covered with mirrors which scanned the subject and projected the varying light intensities onto a selenium cell. France's Rignoux and Fournier put an extremely bright light behind the disk, eliminating the necessity of intensely lighting the subject. Their system became known as the "flying spot" system because of the brightness of the rapidly moving beam of light. The sluggishness of selenium was a problem until 1889, when Julius Elster and Hans Geitel discovered that sodium, potassium, rubidium, and caesium displayed photoelectric activity when exposed to normal levels of light.

By 1908, a workable system of wireless communication had been developed; one which could send a modulated carrier wave over long distances to a receiver. Radio's popularity fueled people's interest in television. In fact, it was around this time that the word "television" entered the English language. The French apparently were the first to use the word; its first documented use in English occurred in the magazine Athenaeum on September 25, 1909 in an article translated from French.

Radio set precedents which the public expected television to follow. It would have to be transmitted "wirelessly through the ether" as was radio. This made single-channel sequential scanning a necessity. Most Americans believed that television would someday provide the same types of programming that radio did, so television, like radio, would become an advertiser-supported medium. These expectations meant that television would have to be of high enough quality to make it marketable to the public and to potential advertisers. Many scientists envisioned high-definition electronic television systems, but their ideas were way ahead of the necessary technology, so efforts to perfect a mechanical television system continued.

The Baird Televisior was a mechanical TV that was sold in Britain beginning in 1930. In addition to the viewer constantly having to adjust the speed of the rotating disk in the receiver, he also had to contend with the "whirring" noise of the motor and the spinning of the disk. (Photo courtesy of Canadian Museum of Civilization).

America's C. Francis Jenkins and England's John Logie Baird were the leading researchers in this field going into the 1920's. Jenkins, inventor of the "phantoscope" motion picture projector in 1894, had invented a system of prismatic rings to replace the shutter on his film projector. He applied this idea to television, using the rings to replace the rotating disk as a scanning device. Baird continued improving the disk method. GE's Ernst F. W. Alexanderson improved the "rotating drum" system. All three men demonstrated their systems in the mid-1920's.

AT&T, which had recently invented coaxial cable, presented a spectacular demonstration of television on April 8, 1927. The face of Herbert Hoover was "plainly imaged" as he spoke in Washington, DC and was "flashed by wire" to New York, where it was watched by an audience of business executives, which included RCA's David Sarnoff. The audience also saw a demonstration of wireless television. Both were watched on a large mosaic of 2,500 squares, each one individually wired to a rotating brush, which supplied current to them in succession. After the demonstration, AT&T said they had no idea if television would ever be commercially available.

Philo Farnsworth generally gets credit for being the inventor of electronic television because his "image disector" tube was the first to result in a viewable television picture. A fierce 50-MILLION-dollar legal battle erupted over this because Vladimir Zworykin was the first to apply for the patent (and if you think that's a lot now, remember, this happened in the 1930s!). (Photo compliments of Getty Images).

RCA began broadcasting a 60-line picture at 20 frames per second in April, 1928. The first test broadcasts were of a model of America's first television "star," Felix the Cat, which spun around endlessly on a turntable. Jenkins Television of New York began "sending out" movies on April 1, 1929; two weeks later, they began selling Jenkins "television receiving devices" to those interested in watching them. On July 30, 1930, RCA moved its facilities to the Empire State Building where it began transmitting a new 120-line picture as NBC. Results far exceeded the quality of all previous endeavors, but mechanical television, though vastly improved, was still not of sufficient quality to interest the business community.

The history of electronic television began with the invention of the cathode ray tube. Around 1859, Sir William Crookes observed that a high voltage applied to the cathode and anode of a vacuum tube caused a fluorescent "storm" of electrons to flow from terminal to terminal. In 1897, Germany's Karl Braun added a fluorescent inner surface to one of the tubes and found that it glowed. Russia's Boris Rosing saw Braun's tube as a possible solution to the problems of mechanical television receivers and successfully demonstrated a crude CRT receiver in 1908 which used deflecting coils to focus the scanning beam.

In 1912, England's A. A. Campbell Swinton proposed the world's first all-electronic television system. His design used Rosing's cathode ray receiver and went one step further--employing a cathode ray tube in the transmitter which operated in synchronization with the one in the receiver. The image would be focused onto a photoelectric mosaic which would be scanned on the other side by the cathode ray. Bright areas of the mosaic would emit electrons when scanned. These would provide the signal. Swinton's attempts to build such a system failed because of the limited technology of the time. However, his idea lives on and is, in essence, the system used today.

Vladimir Zworykin is credited as being the father of modern television. Though he was the first to hold the patent for the electron scanning tube, Farnsworth's was the first one that worked. Zworykin later improved the design and the result was his "iconoscope" tube. But the patent was eventually awarded to Farnsworth.

In 1919, a Russian, Vladimir Zworykin emigrated to the USA and went to work for Westinghouse. Zworykin was a former student of Rosing and had been a communication specialist in the Czarist army. Building upon Swinton's design, he introduced the concept of "signal storage" in 1923. Charges accumulated photoelectrically on parts of the mosaic that weren't being scanned, resulting in a stronger signal when they were. Early tests of the tube were unsuccessful, so Zworykin decided to devote his time to the perfection of a CRT receiving tube. He demonstrated his perfected "kinescope" in 1929. Zworykin then went back to finish the pickup tube. By 1931 he had worked out the bugs, and two years later he publicly demonstrated his new tube, called the "iconoscope".

Meanwhile, young Philo T. Farnsworth was conducting his own experiments in Idaho. After studying the work of Rosing he began contemplating his own electronic television system. In 1922, the sixteen-year-old Farnsworth astonished his high school science teacher by asking for his advice on it. Upon finding sponsors, he moved to San Francisco, where he developed his "image dissector" tube, named for the method in which the image was scanned. Deflector coils swept the entire electron image, moving it both vertically and horizontally past an electronic "shutter" which was actually a small hole. The signal was created as electrons entered the hole in varying intensity and were collected by a "multiplier." Farnsworth demonstrated his design, which "made cigarette smoke plainly visible in reproducing a likeness of a man smoking," on September 3, 1928.

Felix the Cat, spinning around on a turntable, was America's first television star. Here, you can see the entire setup, circa 1930. (Photo from one of PG's broadcasting textbooks).

Farnsworth applied for a patent on electronic television and got it in 1924. Zworykin, now with RCA, visited Farnsworth's laboratory. So did Sarnoff. Both were impressed with Farnsworth's achievements but were not interested in buying the rights to them, having developed a system of their own. But Farnsworth held a key patent, forcing RCA to negotiate. A cross-licensing agreement was reached in 1939, much to the chagrin of RCA. As the contract was signed, the RCA attorney became so upset that he cried.

RCA had begun field testing Zworykin's system in 1936 after building a new electronic transmitter in their Empire State Building facility. They were now free to introduce their new image iconoscope tube which combined the ideas of both Zworykin and Farnsworth. The next year an improved version of the tube was invented, called the "orthiconoscope"--from the Greek word "orthos" (straight) and iconoscope--because its electron gun directly faced the mosaic instead of being set at an angle as in its predecessor.

There now were several different television systems. In addition to RCA's, there were alternative systems from Philco, DuMont and CBS. Each operated with different technical standards. The FCC, knowing that a uniform system was essential if commercial television was to become a reality, formed the National Television Standards Committee in 1940. After much debate over frequency allocation and bandwidth, they authorized the beginning of commercial telecasting in May 1941, to begin on July 1 of the same year. RCA-NBC's W2-XBS, now WNBT, was the only station whose facilities were ready; they began carrying the nation's first commercial television broadcasts the same day.

These photos of Felix in 1928, 1936, 1937, respectively, show how the quality of the television picture improved as the engineers made improvements and slowly got it right. (Photo courtesy of www.felixthecat.com)

America's television boom was about to occur when the Japanese drew America into WWII the following December. Work on television was suspended as scientists concentrated on the war effort. The war increased America's interest in technology. When it was over in 1945, servicemen needed jobs. Factories used for the war effort needed something new to manufacture. The boom, which had been put on hold, was waiting to happen. Scientists again turned their attention to television and soon perfected the image orthicon, which combined elements of the iconoscope, the orthicon, and the Farnsworth dissector and which was 100 times more sensitive than any previous pickup tube. "I-O" tubes are still used in some studio cameras today.

The FCC, fearing disputes over frequency allocations, placed a freeze on TV station authorizations on September 30, 1948, because "the limited VHF band was becoming crowded during the post-war boom of the industry." During the freeze, frequencies were allocated to all parts of the country. The commission also worked on a proposal which standardized future color television systems and made them compatible with existing black-and-white sets. The freeze was lifted in April, 1952. 2,053 new stations soon went on the air, and what became known as "the Golden Age of Television" was underway.

The RCA-630 was the first mass-produced television set and was sold from 1946 well into the 1950s. (Photo courtesy of www.earlytelevision.org)

Television is a technological wonder which seemed, to many, to have instantaneously appeared to fill the post-WWII vacuum in America. However, the process was actually the culmination of a century of independent discoveries which included the phenomenon of persistence of vision, the facsimile machine, and the photoelectric properties of certain metals. Multi-channel systems were attempted, but proved to be too cumbersome. Mechanical television endeavors produced a workable system, but it was not of high enough quality to interest potential investors and advertisers.

Finally, scientists developed the electronic television system used today. Zworykin's kinescope has changed little since 1929. After the war, Farnsworth's and Zworykin's ideas were "married" into the image orthicon tube, which is still used in some contemporary television cameras. The resulting system was hundreds of times more sensitive than the selenium mosaics and scanning disks of its ancestors. The single-channel sequential signal could travel as a modulated carrier wave as did radio. Best of all, it was soon discovered that color could be achieved by, essentially, using the same system in triplicate. Today's television system barely resembles its predecessors in function and theory. This makes television an exception in the world of technology, where the first solution to a problem tends to define those which follow.

The Zenith B3006E was the hot new television that went on sale in 1959. There were probably lots of people in the WSLS-TV viewing area who went out and bought one of these, got it home, hooked it up, and turned it on just in time for dinner—then broke in their new television by watching Uncle Looney. (Photo courtesy of www.earlytelevision.org)

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