Do You Know?
W. H. Samelius, Chairman
Science of Horology and Technical Board
The name "Pendule" was given to watches in which the pallet arbor was placed across the verge escape wheel and to this arbor was attached two arms, each arm having a small weight attached to the outer end, which acted as a balance. There was an opening in the dial showing one of these weights moving to and fro which then appeared similar to the motion of the pendulum of a clock.
The rack lever escapement was invented by Peter Litherland of Liverpool, England, 1781. At the end of the lever was a segment into which teeth were cut, engaging a pinion which took the place of a balance staff and the motion of the lever to and fro would cause the balance to vibrate the same as our watch of today. The lever at no time was detached. While the method secured a steady action it entailed considerable friction and for that reason the rack lever was soon abandoned.
With the regular 15-tooth escape wheel and the 4th wheel having ten times as many teeth as the escape pinion, the balance beats 18,000 vibrations per hour.
When the 4th wheel has nine times as many teeth as the escape pinion the balance vibrates 15,200 per hour. When the 4th wheel has 8 times as many teeth as the escape pinion the balance vibrates 14,400 per hour.
As compared to the solar day, the siderial clock gains 9 5/6 seconds per hour or 3 minutes, 56 seconds in 24 hours.
In 1891, a head-on collision occurred near Kipton, Ohio, killing the engineer and several railway mail clerks. Investigation disclosed there was a difference of four minutes of time as shown by the engineers' watches. This was the cause of loss of life and property. Mr. Webb C. Ball, a jeweler at Cleveland, Ohio, was a witness to the investigation. Interest was aroused so he worked out a system for a plan of inspection for all railroad watches which was accepted and is today in operation on practically all railroads in the country.
It is claimed that Sandoz & Trot was the firm that established the first watch factory in Switzerland in 1804. Previous to that time watchmaking had been a house industry.
The screw bezel for watch cases was invented by E. C. Fitch of 1886. He was one of the early presidents of the Waltham Watch Company.
Gnomonics: The art of constructing and setting sun dials taught extensively during the 17th Century.
Guild: An association of workmen employed in kindred pursuit for mutual protection and aid.
It is believed that Ctesibus, a famous Greek mechanician, that lived in Alexandria, was the first man to apply toothed wheels to the Clepsydra about 140 B. C.
Dog-Watch: A nautical term for two daily two-hour periods of watching aboard ship. The first begins at 4 p. m. and the other at 6 p. m.