Electronics in Control

One of the most important U.S. task forces of World War II--which may do the enemy as much damage as any that the nation sends overseas--consists of several thousand scientists. In complete military secrecy they all work together in one big building at one big scientific institution on one big problem: wartime applications of and improvements on the electron tube.*

The incredible accuracy of U.S. naval guns at Casablanca, which at 26 miles smashed the hull of the French battleship Jean Bart in two salvos, was a triumph for the electron tube. Declared Rear Admiral Stanford C. Hooper last week: "Radio directed and reported the destruction." Even at the very hour that war began the electron tube was the first to serve the nation. On Dec. 7, 1941 the electron tube caught the mutter of Japanese aircraft when they were 132 miles away from Pearl Harbor.

No man can see 132 miles, or even 26, and the men at Pearl Harbor and Casablanca were no exceptions. But the electron tube can. What is more, the electron tube can hear, feel, taste, remember, measure, count and talk. Unable to think and without a conscience, the tube is still less than human. But with proper accessories it far exceeds the human senses (except taste and smell) in keenness.

Its vision, for instance, allows it to "see" beyond the horizon, through fog and clouds, in black dark. It can "see" through stone and steel to detect invisible internal flaws. It can "see" the whiskers on a disease germ that is only a speck in the best microscope.

With electron tubes any combat unit, even a plane streaking across the night sky above the clouds, is in close touch with its command post. Army headquarters in Australia, Iceland, Tunisia, China are neighboring plugs on a single electronic switchboard.

When war ends, the new war-born developments will "go to peace." Already electron tubes of various forms can accomplish miraculous things:

> Count and sort merchandise, match colors and finishes, gauge size and thickness of materials to a millionth of an inch.

> Measure, control and record pressure, humidity, temperature, color, acidity.

> Detect fog, smoke, dust and vapors that are invisible to the eye, and take protective action.

> Control any machine operated by a relay switch--manipulating doors, elevators, conveyors, furnaces, traffic.

> Operate machines by remote control--in lighthouses, electric substations, pumps, planes, ships (TIME, Jan. 18).

> Concentrate heat in small areas even deep within the insides of larger objects--to bake, dry, glue, stitch, anneal, weld, rivet.

> Motivate many medical treatments-by-heat which come under the heading of diathermy.

The electronic industry was no dwarf in the peacetime U.S. Then nearly 150 million tubes, of more than 400 different types, were produced in a year. Radio equipment production jumped from well under half a billion dollars in 1941 to $1 billion in 1942. Plans for 1943 will bring the production figure to $3 billion. Military secrecy cloaks the uses to which tubes are being put but these totals tell the story of their myriad usefulness.

Mechanism of Revolution. Actual father of electronics is Lee De Forest.* who evolved the first modern electron tube in 1906. But the grandfather was Thomas Alva Edison. He noticed in 1883 that the hot wire in his new light bulb gave off electricity, but he could neither understand nor use the effect. In 1904 Sir J. Ambrose Fleming sealed a separate metal plate through the glass into an Edison light bulb, was able to draw current from the plate. De Forest added the grid. How many electrons from the filament reach the plate, and how fast, depends on the intervening grid which is acted upon by incoming electric stimuli.

The grid is the sense organ of the tube. To it is attached an antenna if the tube is to be used for radio reception, a microphone if it is to amplify sound, or an electric eye if it is to respond to light signals. Changes of voltage on the grid change the current from filament to plate. In each case the extremely faint stimuli received by the grid are amplified to hundreds of times their original strength. By using several tubes, with the plate of one connected to the grid of the next, the amplification can be multiplied to thousands or millions.

The plate is attached to the outgoing circuit leading to a radio loudspeaker, or public-address system, or telephone, or a magnet which controls an electric switch if the tube is to set a machine in motion. In the illustration, the electric eye is immune to the correct color of healthy oranges. When it "sees" a defective orange it sends a slight current to the grid. This steps up the current from filament to plate, causes a magnet to operate an ejector device which instantly sends that orange out of the packing line.

Great new streamscapes of the electronic world may be visible at the war's end:

> Detectors on ocean vessels to make visible other ships, icebergs, shores, through night and thick fog.

> Very short radio waves to multiply available radio channels, possibly by many thousands, making possible wide use of radiotelephones by truck fleets, construction gangs, large-scale industrial and mining operations.

> Television to project pictures on screens 18 by 24 feet, in full color (already possible). Programs are now picked up at Schenectady from Manhattan, 135 miles away, forecasting national network programs by relay stations.

* Often and deceptively called the "radio" tube (which suggests only a fraction of its uses). * Sharp-eyed, white-fringed Lee De Forest, 69, inventor of hundreds of subsequent electronic devices, maker and loser of several fortunes, now lives in a huge hillside home at Hollywood, drives daily to his unimpressive laboratory on Wilshire Boulevard, is putting into production an altimeter which indicates the height of a plane above the actual ground beneath instead of sea level. He also manufactures diathermy equipment, to which he credits his own excellent health. Last July in a single week he climbed both Mt. Whitney (highest in the U.S.) and Mt. Langley.

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