Page:St. Nicholas, vol. 40.1 (1912-1913).djvu/105

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NATURE AND SCIENCE FOR YOUNG FOLKS
73


Twelve tiny screws and six jewel-pins. An escape-wheel. An escape-pinion.
(Magnified and photographed with the head of a medium-sized pin to show relative size.)

The Wonders of a Watch

It is a matter of every-day occurrence for a person to say to his watchmaker, “Here is a
Three tiny screws holding a small jewel.
(Greatly magnified.)
watch which you sold me ten years ago. It has gone well till lately, when it has taken to stopping without any apparent cause.”

The people who speak in this way little think of the amount of work that a watch has performed in this space of time, and may be astonished at the following figures:

“In ten years,’ says London “Answers,” “which include two leap-years, and consequently a total of 3652 days, the hour-hand has made 7306 and the minute-hand 87,648 revolutions. The end of an average minute-hand has traveled more than 10,280 yards—more than six miles. The second-hand has made 5,258,880 revolutions, and its extremity has traversed on the dial a distance of nearly 123 miles. The escape-wheel has made 52,588,880 revolutions, and as it has fifteen teeth, it has come 788,832,000 times in contact with each pallet. The balance-wheel has made 1,577,064,000 vibrations, and any point on the outside of the rim has covered a distance of about 50,000 miles, and that is equal to twice the circumference of the earth.”

These amazing statements and figures have been submitted to the Elgin National Watch Company of Elgin, Illinois, and Mr. George E. Hunter, the superintendent, says that they are almost right for an Elgin watch, small changes being due to the size of the watch. In the Elgin No. 16 size, the end of the minute-hand in ten years travels 11,473 yards; in No. 18 size, 12,238 yards. The second-hand in No. 16 travels 130.38 miles; in No. 18, 143.42 miles. A point on the outside rim of the balance-wheel of 16 and of 18 respectively, travels 44,511 and 48,891 miles.

Interesting as these figures are, and surprising as are the distances traversed, one’s interest is increased by a knowledge of the amount of force,
The “pallet and fork” which works in connection with the escape-wheel.
(Magnified about three times.)
in horse-power, required to drive an Elgin watch, size 18. Of this Mr. Hunter says: “All watches are built to run for at least thirty hours, and on that basis, the power required to drive an 18 size

Vol. XL.—10.