Evening Star Newspaper, October 25, 1931, Page 79

THE SUNDAY STAR, WASHIN( e T S Marvelous BOTTLES OF NOTHING Nature Abhors a Vacuum, but the Vacuum T'ube Has Become Man’s Best Friend, Seeing, Hearing, Smelling, Tasting, Feeling, Thinking in More Than 200 Different Ways. BY ISRAEL KLEIN. UT of almost nothing, sealed in an airtight bottle, man has succeeded in getting more than he has out of any more substantial substance on earth. Vacuum, the absence of air, has not deterred him, but helped him. The vacuum tube has become an electric brain—modern civ- flization's greatest gift. Yet it has become so only within the short Bpan of the last 25 years. In fact, its capabili- tles have been known and developed only within the years of the modern adult genera- fion. It was in the Fall of 1879, only 52 years ago, ¢hat Thomas Alva Edison produced the first electric light. What he succeeded in doing was to exhaust enough air from a glass bulb, so that & carbonized thread within the bulb, heated by plectric current, burned for 40 hours. And it wasn’t until 1883 that he discovered something happening within his bulb that sclentists now are making use of in a big and practical way. That was termed the Edison effect, the escape of ultra-minute electrons from the heated fila- ment. Nothing was done about the Edison effect for a while. Edison himself was content with developing the electric light, the first andetoday the most widely used vacuum tube in the world. Por the electric light is in reality only a simple yacuum tube—merely a burning filament “set on fire” by an electric current passing through i3, and made possible by the existence of a yacuum, or rather the non-existence of air. The vacuum, to be sure, is not complete. Man basn't yet succeeded in securing a complete abeence of air. But air is evacuated from these fubes up to a point at which the best lighting effect is obtained. DAY, scientists evacuate air and insert a | small amount of an inert gas like neon into the tube to obtain some special effects. Or they add a drop or two of mercury or some other chemical element to obtain other effects. Or they coat the interior of the vacuum tube oontainer with an element to get still other results Out of each of these possibilities have arisen Dew uses for the vacuum tube, uses that are growing In number and importance almost weekly. There's radio, perhaps the most marvelous discovery of the twentieth century, The Edison effect led to it First to realize the possibilities of the escap- ing electrons from a lighted filament in a vacuum tube was Sir John Ambrose Fleming, British scientist, who, in 1904, put these elec- trons to some practical use by catching them on a small electrically connected plate inside the tube. That was a crude, elemental form of wire- Bess tube until Dr. Lee De Forest, young Amer- fcan sclentist, installed a third element into the tube two ycars later and succeeded in con- trolling the flow of electrons from filament to plate. That third element he called a grid, a sort of gate through which the electrons flowed and which could control this flow by means of a varying electrical charge. There’s your simple radio tube. Of course, today, there are four and five element radio tubes, having two and three grids for mucn more accurate and effective control of the elec- tron flow. It was 1906 when De Forest inserted that grid into the vacuum tube. Yet a quarter cen- tury later millions of listeners throughout the world are enjoying entertainments produced out of sight and physical reach, all through the aid of these vacuum tubes. HE radio tube has gone even further. It has made the talkies possible and it has per- mitted considerable improvement in the re- cording of music and voices for improved types of phonographs. Even more promising is television. Here is a combination of both radio vacuum tube and the electric sye. The electric eye to the scientist is called the photo-electric cell. It is actually a vacuum tube that sees, one that converts this vision into corresponding electric impulses, just as the radio tube converts the sound it hears into similar electric impulses. Instead of De Forest's grid, however, the elec- tric eye makes use of a thin layer of some alka- lin element, like potassium, caesium, selenium and so on, which Is even more sensitive to light and its variations than the pupil of the human eye. It s only a matter of connecting this sensitive layer to an electric circuit to get the resulls scientists have succeeded in obtaining from this unusual phenomenon. Television is the most Tfar-reaching and promising possibility. But while television is still in the experimental stage, the scientists have put the electric eye to some 200 practical uses and are finding new applications for it al- most as fast as the demand arises. TALKING motion pictures, in their projection, require the use of the electric eye to catch the sound tracks alongside the film and con- vert these waving lines of light and shade into corresponding sounds. Here, in other words, is an instrument so remarkable that it even sees sounds. In fact, the electric eye has been made to feel, to hear, to taste and to smell, besides see- ing, applying all the five physical senses of man through its single virtue of sight, As an instrument of feeling, for example, the photoelectric cell is being used in some of the large paper mills to detect flaws in paper as it passes through the rollers, to “feel” its thick- ness and discard that which does not come up to specifications. In the reproduction of talkies, the electric eye becomes an electric ear, “hearing” electrically the sounds that had been deposited on the film at the time the scenes were photographed and rcorded Similarly, the senses of taste and smell are 0N, D. €, . OCTOBER 25 193Y. 5 msam——— caught by this ubiquitous eye, converted into electric current and recorded for the benefit of observers, The smell of smoke belching un- duly from a chimney quickly raises an alarm, through this instrument. The rise of a poison- ous gas in a tunnel, or a mine where men are working, can go no farther than the extremeiy sensitive “nose” of this unique vacuum tube. On the West Coast the electric eye is “tast- ing” fruits and grading them for the various markets. In an Ohio steel mill, white-hot molten metal is being kept within a very few degrees of a constant high temperature, more effectively than man has ever been able to keep it. IGHTS are being turned on whenever it gets dark enough, banks are being guarded, traffic is counted, colors are sorted and many other duties heretofore performed by man are being fulfilled by this vacuum tube. It has converted the five senses into one— that of sight. So sensitive is its sight that it can see what man has to detect by one of the other senses more adequate for the purpose. There is, for instance, a vacuum tube that measures a hundredth of a millionth of a bil- lionth of an ampere of electric current, that 1s so sensitive as to react to the slightest electrical impulse and is so powerful as to start high- powered machinery or control deadly electric currents. The bend in a table top made by a 25-cent piece can be measured by an ultra-micrometer, of which this tube is the heart! Yet the same tube will enable electric engineers to double the practical length of their high-power lines carrying up to 220,000 volts of current! For the various services these tubes are to perform, they are built differently. But fun- damentally they are the “thyratron” or the “grid-glow” tube, depending on whether they come from the General Electric or the West- inghouse plants. Combine one of these with a photoetectric cell and you can fashion a robot or mechanical man that will do almost anything but think, N war, as in peace, this robot promises to have its uses. The United States Army recently demonstrated a robot anti-aircraft gun whose sharp “ears” discovered an “enemy” airplane long before any human ears could, and which immedigtely found the range and the altitude of the plane, then aimed the gun and fired. No human hand touched the anti-aircraft gun, yet it is said to be much quicker and more accurate than any heretofore in use. Furthermore, there’s the radio-controlled warship and the radio-controlled airplane, both making use of the radio vacuum tube, the “thyratron” or “grid-glow” tube and the electric eye. Without a man on board, a ship “manned” by the modern robot can be made to maneuver ir all directions and at all speeds, even to fire its guns and throw a smoke screen, at the command of an officer on a ship several miles away. Most extraordinary, perhaps, a blind man places a book, not in Braille, but printed in regular type, before a strange instrument whose interior consists of an electric eye, a disc witn The glowing pano- rama of a city at night made possible by vacuum tubes with one of the miracle- working “bottles of nothing” in the ". m‘- several holes in five rows, a light which shines through these holes upon the lines of type and is reflected back upon the electric eye, a bate tery and a set of earphones. He turns on the current and actually hears the instrument read the book for him! i CIENTISTS at Schenectady and at Pasadena are building huge vacuum tubes of a dif- ferent nature, raising their voltages to one mil- lion, two million, even five million volts, power= ful enough to kill a whole regiment, more powerful than a ton of radium, in some sort of effort to find a more practical treatment for cancer and other fatal diseases. Death-dealing X-rays to defeat death! In several modern hospitals in New York, Chicago, Rochester, Albany, physicians are placing patients, suffering from diseases here= tofore believed incurable, upon a box-like table, turning on a current and awaiting the effect of powerful, but tiny radio waves upon their bodies. These waves, emanating from a tube that oscillates at between 10,000,000 and 14,000,000 cycles a second, have been found to raise & fever in the patient, what physicians have dis- covered is needed to kill the germs of such diseases as paresis, arthritis and various other Jjoint diseases. The list of possibilities for the vacuum tube is aknost inexhaustible. Two hundred practical uses already, yet the vacuum tube has only be- gun to demonstrate its availability. The range is almost infinite. A Schemer Comes to Grz'ef NE salesman with a fine scheme is spendw ing six months in an Iowa jail, considere Ing the error of his ways in trying to play both ends against the middle. He visited farmers in the guise of a Federal poultry and swine ine spector. This went unchallenged for the Feds eral Government is conducting an intensive campaign in Towa looking to the eradication of tuberculosis among the poultry and swine. The energetic “inspector” found tuberculosi§ highly prevalent and had a remedy that h§ would gladly sell to the anxious owners of the fAocks. Curiosity was aroused, however, over the fact that a Government agent was in private business at the same time with the result that the “agent” is now “In” but not in business nor yet In the Government service.