DOUBLE BOTTOM CASE—A watch case in which the inner cover or bottom is made solid with the middle. The vogue in English cases for a long time; now almost obsolete. DOUBLE-SUNK DIAL—A dial in which there are two sinks; one for the hour hand, and a deeper one for the seconds hand. DRAW—1. The force which holds the lever against its bank, due chiefly to the angle of the locking face of the pallet stone. 2. The angle of the locking faces of pallets in the lever escapement. DRIVER—Of two wheels working together, the one which imparts the power. The driven wheel is termed the follower. DRIVING WHEEL—In a clock the wheel on the main arbor which drives the whole train. DROP—That part of the motion of the escape wheel when it is not in contact with the pallet. DRUM—The cylinder, or barrel, on the main arbor in a clock on which the driving cord winds, raising the weight, when the clock is being wound. DUMMY WATCH—(Fausse Montre.) About 1770 it became the fashion to wear two watches. But because two real watches were too expensive for most people, the custom grew up for having one sham watch—usually worn on the right side. These were called "dummy watches" or "fausse montres." EARNSHAW, THOMAS—1749-1829. An eminent English watchmaker who invented the spring detent escapement and the compensation balance, both essentially the same as are now used in chronometers. He first soldered brass and steel together for the balance instead of riveting them. EAST, EDWARD—Watchmaker to Charles I and an eminent horologist. He was one of the ten original assistants named in the charter of the Clockmakers' Company and at once took a leading part in their proceedings. He was elected master in 1664 and 1682. He was the only treasurer ever appointed by that company. He died probably about 1693. East's watches were often presented as prizes by Charles in tennis tournaments. EDWARD VI—King of England from 1546 to 1553. Said to have been the first Englishman to wear a watch. ELECTRIC CLOCK—A clock in which the pallets moved electrically from a distant mechanism drive the escape wheel and the hands. ECLIPTIC—That plane passing through the center of the sun in which lies the orbit of the earth. Also used to designate the apparent path of the sun in the heavens. ELGIN—A city in Illinois, U. S. A., in which is located the Elgin National Watch Company—one of the largest factories in the United States. END-SHAKE—Freedom of pivots to move endways. Necessary in a watch or clock because there is no force to spare and a tight pivot would stop the movement. END-STONE—A small disc of jewel against which the end of a pivot sets. See _Capped Jewel_. END-STOP—In a watch the same as end-stone. ENGAGING FRICTION—Friction which results when the teeth of two wheels gearing together come into action before reaching the line of centers—that is, a line drawn from center to center of the gearing wheels.