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Show A MILLIONTH OF AN INCH In today's magic world of science seldom is there found anything more remarkable than the amazing process of measurements now in use in many major industries. A few centuries ago an inch was three grains of barley laid end to end. A foot was just what the name indicates, the length of a human foot. A yard was the distance from the nose to the thumb of an outstretched out-stretched arm even in our lifetime fabrics were measured that way in dry-goods stores. Science evolved units of measure-rnent measure-rnent for weight, for electrical current, cur-rent, for time, and for other units, but for years an accurate unit of measurement for length defied the greatest scientific minds. It remained for Carl Edward Johansson, a Swedish immigrant, to solve the mystifying puzzle by discovering dis-covering a process which earned him recognition as the , acknowledged acknowl-edged head of scientific Industrial measurement in the world today. Traveling on a train one day, pondering the delays in assembling rifle parts due to inaccuracy, and the difficulty of interchanging parts which were supposed to be exactly alike, a great idea for the precision measurement of length dawned upon up-on him. The idea was developed, but the world was slow to accept this valuable contribution. The first industry to equip its plants with the Johansson system of gauges was the Ford Motor Company, Com-pany, which secured the rights for North and South America and made them available to any industry on equal terms with itself. Since then the Johansson gauges have come to play a vitally important part in the igreat Ford industries, according to C. A. Morley, local Ford dealer. Said Mr. Morley: "Take a human hair, split it 1500 times, and each part will be about two one-mil-lionths of an inch thick or rather, thin. The operating gauges used in Ford factories are checked by master mas-ter gauges which measure within one-half of the . gossamer thickness of one of these 15 hundred splits of a human hair, or within onemil-lionth onemil-lionth of an inch. A millionth of an inch is constantly being measured meas-ured at Dearborn. "For ordinary measurements in the inspection and machining of parts for the Ford car there is a tolerance of five 10-thousandths of an inch, or half the thickness of a sheet of onion-skin paper. A few measurements are held as close as two 10-thousandths of an inch, to insure longer operating life, or less wear, in the parts. This is one of the reasons why Ford cars can be driven fifty miles an hour for the first one hundred miles, and after that, as fast as the driver chooses. "The gauges oised in making the Ford car are now used for national standards of measurement at Washington, Wash-ington, Paris, and London, and by all the principal governments. Since 1930 every industrial nation in the world has adopted the Johansson standard of temperature for measuring measur-ing devices. |