The Montgomery advertiser., 1902-04-27
THE. EARTH'S MOTION
PENDULUM 200 FEET LONG RIG
 GED UP BY SCIENTISTS.
How Foucault's Wonderful Experi- ment of Fifty Years Ago in the Roman Pantheon Will Be Re- peated to Settle Question of
 Its Scientific Value.

Paris Special to New York World.
 The most brilliant experiment ever made in astronomy is about to be repeated by the Astronomical Society of Paris.
 It is known to all scientists as ''the pendulum experiment of Foucault," and it's purpose is to prove the circular mo- ton of the earth
 Foucault, who first conceived the idea was the most ingenious of all French scientists of the generation just passed Tn 1851, when he was a pupil of Arago he asserted that if long pendulum were suspended inside a very high building and put in motion the movement of the earth from west to east would be shown by the changing of the surface underneath the pendulum.
 He. illustrated his idea by swinging a pendulum above slowly revolving table It was seen that the twisting of the wire did not alter the direction in which tho pendulum was swinging. and Foucault's idea. as theory, was clearly demon strated.
 After overcoming a great many difficult ties. Foucau1t at last obtained permission to try his idea in the Pantheon at Rome. He asserted that his theory could be made clear to every one who had eyes to see the proofs.
 The dome of this famous building. the Pantheon, Is 2S5 feet in height and the ceiling in the main hall is 200 feet from the floor. Foucault, then an enthusiastic young scientist in his twenties, managed to fasten a. steel wire to the centre of the ceiling and attached heavy ball of metal to the lower end of the wire.
 The metal ball was suspended half an inch above circular mahogany table. twelve feet in diameter. hollowed ont slightly and with little rim of fine sand running around the edge of 1t.
 A needle was inserted in the under side of the metal ball, projecting nearly half an inch downward, so that it almost touched the surface of the table and made a line whenever it touched the rim of sand.
 Pulling the pendulum out beyond the edge of the table Foucault fastened 1t with a cotton string and when the wire was perfectly motionless set fire to the string and released the pendulum
 In a few moments, to his great delight, the floor was distinctly seen to move un- derneath the pendulum. Every time the long pendulum swung through the ridge of sand 1t made its mark in new place. The floor was twisting about at the rate of one revolution every twenty-four hours and the unchanging pendulum was mark ing time with each swing.
 At once the news was sent around the world that the motion of the earth could be seen as plainly as the motion of the clocks wheels are shown by watching its hands.
 The experiment created the greatest en- thusiasm among scientific circles and placed the young Frenchman among the worlds greatest astronomers. No his tory of astronomy is complete today without the name of Foucault and the history of his famous pendulum.
 During the past year the experiment. has been criticised by Professor A. $. Chessin an eminent astronomer, now stationed at Washington University. St. Louis Professor Chessin maintains that a different result might have been ob- tained if the metal ball had been shaped like a dumbbeil. A paper which he pre- pared on the subject has aroused con- siderable discussion among scientists. and the Paris Astronomical Society is about to repeat the experiment mainly to test Professor Chessin's suggestions.
 Professor Chessin is a Frenchman of noble birth. exiled to America becaue of his political opinions Having turned his attention to science. he has become one of the best known astronomers in the Middle West.
 The Astronomical Society of Paris has chosen the Pantheon as the place where the experiment is to be repeated. Tn many respects thls ancient building