Page:Popular Science December 1931.djvu/131

 AGE-OLD QUEST FOR PERFECT TIMEPIECE (Continued from page S3) words, the ancients developed the clepsydra, or water clock. In its simplest form, the clepsydra was nothing but an earthenware globe with sev- eral small holes in the bottom. When a lawyer, senator, or other orator started his harangue, the globe was fdlcd with water. He was informed that his time was up when all the water had run out. Ever since then, there has been a con- tinuous search for more and more accu- rate timekeeping machinery. The hourglass of our ancestors, consisting of two glass globes connected by a small aperture, one of them filled with a quantity of fine sand, was one of the many adaptations of the classical water clock. During the first si.xteen centuries of our calendar, all sorts of complicated mechanisms were produced. They looked quite impres- sive, but as timekeepers they were not much better than the early water clock. A great change came in 1583. One morn- ing in that year, a nineteen-year-old student in the University of Pisa, Italy, attended ] mass in the cathedral. His mind was diverted I from the service by the swinging of a lamp overhead. Timing the swings by feeling his i own pulse, he found that each .swing was accomplished in precisely the same period. The youth was Galileo, and that is how he discovered the law of the pendulum. THE use of the pendulum marks the begin- ning of accurate timekeeping, for the first clock that made any pretense to keeping true time was provided with a pendulum. It is safe to say that the same simple mech- anism also is the last word in correct time recording, for the most accurate clock in the world today is merely a piece of machin- ery designed to drive a most exquisitely refined pendulum. The pendulum clock had and still has one great disadvantage — it isn't exactly the thing to carry around with one. Even before the pendulum clock was thought of, experi- menters were working on portable time- pieces and, toward the end of the fifteenth century, German craftsmen produced what then was considered a masterpiece — the so- called "Nuremberg egg," great granddaddy of your pocket watch. Nearly as big as your alarm clock, the Nuremberg eggs did not amount to much as timekeepers, but they were so beautifully designed and so richly decorated as to con- stitute works of art. In those days, only kings and nobles had timepieces of any kind. The workman of today with only a dollar watch can tell time far more accu- rately than could the medieval king with one of the ornamental eggs. Still, those monstrosities were the forerun- ners of the high-grade modern watch. The first great step forward was the application, near the end of the seventeenth century, of Galileo's pendulum principle to portable timepieces. The invention of the hairspring made it possible to substitute the coiling and uncoiling of a spring for the pull of gravity, so that the balancc-wheel-hair-spring arrangement, introduced at that time, really amounted to a pendulum action. The time- piece thus produced reduced the daily errors of the Nuremberg eggs from half hours to only a few minutes, and the same crude mechanism, without basic change, still is used in the dollar watches and cheap alarm clocks of today. The machinery that makes a really fine watch keep time to the second is not as simple as that. (Continued an ptifjc 12S) THERE'S MONEY TODAY IN ART nPHIS is the day of the artist. His skill is sought ■wherever design and color are important factors in the sale of merchandise. Furniture, rugs, wall hangings, household utensils, wear- ing apparel, jewelry, art gifts, lamps, automobiles — nearly everything sold today depends on design and color to attract the eye of the purchaser. Drawings for advertise- ments in newspapers, magazines, catalogs, folders, posters, display cards and many other media call for the skill of the modern artist. Consider the number of drawings in this magazine alone. Art is a necessity in modern business. If you like to draw, train this talent of yours and put it to work in a field offering rich reward. You can learn drawing at home in your spare time. Many leading artists have contributed exclusive illustrated lessons to our courses. Many of our students and graduates now earn $2500.00 to $6000.00 a year, some a great deal more. SEND FOR OUR FREE ART TEST It brings out your sense of proportion, design and color. Our instruc- tors will give you frank advice as to your talent and probable chance of success. It costs you nothing. Just fill in the coupon below and we will send you this test together with one of the books shown. The book "Your Future" outlines possibilities in the field of drawing for adver- tising. "A Road to Better Things" describes magazine and newspaper illustrating. Each book shows examples of our students' work. Mark on the coupon the book you want and MAIL IT NOW. FEDERAL SCHOOLS. INC. FEDERAL SCHOOLS, INC. 1212-A, Federal Schools BIdK't Minneapolis, Minn. Please send me Free Art Test and book I have checked. C Your Future LJ A Road to BiRger Things Name. Age OccHfxition. Address DECEMBER, 1931 127 Cc(_ ,