The Off-Key Bard
History

This Day in History — Philo Farnsworth Demonstrates Electronic Television

On this day in 1927

On September 7, 1927, Farnsworth transmitted the first all-electronic television image — a line from a triangle slide — while RCA was quietly preparing to steal his idea.

The Off-Key Bard stares at a screen displaying little more than a glowing line. It doesn't look like much — but that line represents a technology that will eventually place moving images from around the world inside billions of homes.

"Mechanical television had already shown that pictures could be transmitted. Farnsworth wanted to do it with electronics."

On this day in 1927, in a small laboratory at 202 Green Street in San Francisco, a 21-year-old inventor named Philo T. Farnsworth and his small team placed a glass slide containing a line drawing of a triangle in front of a device he called the Image Dissector. On the other side of a partition, a receiving tube waited. When Farnsworth activated the system, one line of the triangle appeared on the receiver as a small bluish square of light.

He rotated the slide. The line on the receiver rotated with it.

"That's it, folks!" Farnsworth said. "We've done it! There you have electronic television!"

The image was crude, tiny, and almost comically simple. But it worked in a way that nothing had worked before. No spinning disks. No mechanical parts. An image captured, transmitted, and reconstructed using nothing but electrons.

The Idaho Field, the Chalkboard, and the Idea

Farnsworth had been working toward this moment for nearly a decade. Growing up on a farm in Idaho, he had absorbed the principles of electricity from every science magazine he could find. According to his family's account, he was around 14 years old when the idea came to him while driving a horse-drawn harrow across a field. He watched the parallel furrows passing beneath the implement and thought: if an electron beam could scan an image in horizontal lines the same way a plow sweeps a field row by row, the image could be captured, transmitted as an electrical signal, and reconstructed on a receiver.

In 1922, when he was still in high school in Rigby, Idaho, he sketched the concept on a chalkboard for his chemistry teacher, Justin Tolman. Tolman kept the memory of that drawing carefully, having no idea how important it would become.

The Image Dissector

The heart of Farnsworth's system was his Image Dissector camera tube — a device that converted light into a stream of electrons that could be scanned, transmitted, and reconstructed at a receiver. Unlike the mechanical television systems that used rapidly rotating perforated discs to scan images in analog chunks, Farnsworth's system had no moving mechanical parts. The scanning happened at electron speeds, which meant it could eventually capture fast-moving images that mechanical systems could not.

Farnsworth had moved to San Francisco in 1926 with his new wife Pem and her brother Cliff Gardner, who became the team's glassblower. Gardner hand-formed the delicate vacuum tubes the system required. The team worked in their rented laboratory, scraping together enough funds from their backers — primarily Leslie Gorrell and George Everson — to continue building prototypes. By September 7, 1927, they had a working system.

The following year brought further milestones. In September 1928, when impatient investors arrived wanting to see a return on their money, Farnsworth pointed his camera at a dollar sign drawn on a glass slide and projected it on the receiver. He was responding to their pressure with a joke they could see. The first press demonstration of the system happened around the same time. In 1929, Farnsworth transmitted an image of Pem, making her one of the first people ever to appear on an all-electronic television system.

The War With RCA

In 1930, Vladimir Zworykin came to visit Farnsworth's laboratory. Zworykin presented himself as a representative of Westinghouse interested in Farnsworth's work from a scholarly standpoint. He was no longer working for Westinghouse. He was working for RCA, where David Sarnoff had tasked him with developing RCA's own electronic television system. Zworykin spent the visit taking detailed notes and expressing admiration for Farnsworth's Image Dissector.

RCA subsequently offered Farnsworth $100,000 for his television patents — an amount that sounds substantial but would have transferred all his rights to a corporation that would profit enormously from them. Farnsworth refused. RCA launched a sustained legal campaign to challenge his patents, attempting to establish that Zworykin had conceived the essential elements of electronic television first.

That is where Justin Tolman came in. In court, Farnsworth's former high school teacher appeared as a witness and reproduced from memory the diagram Farnsworth had drawn on his chalkboard in 1922 — five years before the September 7, 1927 demonstration. It established that Farnsworth had conceived the core system as a teenager. The Patent Office ruled in Farnsworth's favor.

In 1939, RCA agreed to pay Farnsworth royalties for his patents — the first time in the corporation's history that it had ever paid royalties to an outside inventor rather than collecting them. Farnsworth ultimately held over 300 patents.

The commercial victory was incomplete. World War II interrupted civilian television broadcasting just as it was getting started. By the time production resumed, critical elements of Farnsworth's technology had been superseded. He suffered from exhaustion and depression in his later years and rarely spoke publicly about his role in television's invention.

The medium that would reshape human communication, entertainment, and politics across the 20th century had been born in a rented San Francisco laboratory from a 21-year-old's memory of plowing furrows in an Idaho field.

"A glowing line upon a screen,
The smallest picture ever seen.
Yet in that light the future grew —
A window through which worlds came through."

History reminds us: revolutionary breakthroughs don't always look revolutionary when they first work. On September 7, 1927, the future of global television wasn't a newscast or a championship game. It was a single line from a triangle, rotating obediently on a screen — and proof that Philo Farnsworth's idea, which had begun in an Idaho field, actually worked.

Sources

← Back to the Desk — History