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Show AN. INTERESTING CLOCK. It Maker I Proud of It, bat He ni Jf Wish to Make Another. In the window of a German jeweler on Court street, Brooklyn, triors stands a brass clock not more than ten inches high. The passerby who looks through the window sees under the clock, which is supported by four polished columns, a small brass platform, balanced to a nicety on two pivots in the middle, like an ordinary seesaw. A groove cut into the surface of the brass runs rigzaff from one end to the other, and on the path bo made a brightly polished steel I baU. no larger than S bullet, runs un-I un-I ceasingly. When the ball has traveled from one end of the platform to the j other, zigzagging from side to side, it strikes a thin steel wire which hangs from above, and in an instant the platform plat-form is tiltod up at that end and the little ball, impelled by the force of gravity, starts back again. At the other end it comes into contact with another wire, and up goes the platform once more. Sometimes "a big crowd stand around the window intent on the littlo sphere, the mystery of which they find it hard to solve. F. T. Kraft, who runs the store, has followed his trade for many years. One day sis years ago Kraft was walking down Broadway when he saw a clock in a jeweler's window with the same device. de-vice. He stood for an hour in front of the glass watching it and trying to solve the problem of its construction. The proprietor of the store told him the clock had been made in England twenty-five years before, and was the only one of its kind in existence. Mr. Kraft's request to have a look at the mechanism was met with a refusal, and he went off with tho determination to study it out for himself. He worked at it six months during hLs odd hours and finally triumphed. tri-umphed. Then he was surprised to find how simple tho idea waa after all, although al-though he found the greatest delicacy necessary in carrying it out. Mr. Kraft took tho clock from its shelf in the window to explain its mechanism to the reporter. The two mysterious wires which the ball strikes against at the end of each trip are fastened above to a long rod. From the upper side of tin's rod runs a strip of steel, which rests against one of four pins on an escapement escape-ment whoel in the works. When . the ball strikes the wire it releases this wheel, which makes a quarter revolution to the next pin. On tho same axis ia a cog wheel whose teeth fit into those of another of half the circumference. The smaller wheel makes a half revolution while the other is making a quarter. To the axis of this wheel is fastened a rod, which is attached at its other end to the platform, which is pulled up or down according ac-cording to the wire which the ball strikes. It waa in the manufacture of the ball itself that Mr. Kraft had the most difficulty. diffi-culty. It had to be a perfect sphere to work properly, and it was turned down bit by bit to the proper size. A little guard rail is placed at each angle of the groove, so that the ball will not jump off. It takes the ball just five seconds to make the trip, a half second for each section of the groove. The platform acts aa a pendulum with a five second swing. The device is only interesting as a novei-ty, novei-ty, aa it is more susceptible to changes in the weather than the pendulum clock, and lias to be regulated frequently. It is interesting to figure out the distance dis-tance which the industrious little ball travels from day to day. Every second it runs 4 2-5 inches, or 22 feet a minute. This is a quarter of a mile an hour, or 6 miles a day, or 180 miles a month, or 21,790 miles a year, over 11,000,000 feet. Since the clock was first started the ball has traveled a distance equal to nearly three-fourths of the way around the globe. In that time it has not been worn to any perceptible degree, although the brass surface on which it runs has been ground off considerably, j "I have had lots of offers for this ; clock," said the old jeweler, as he put it back on its shelf, "but I wouldn't sell it for any price. It was a pleasure to work out the principle of the thing, but you couldn't get me to make another one of them for a good deal." New York Sun. |