THOMAS, SETH—Born at Wolcott, Conn., 1785. A very successful clockmaker who contributed probably more than any other man toward popularizing the modern cheap clock. The Seth Thomas Clock Co., of today, he started in 1813 with twenty operatives. By 1853 it had nine hundred. He died in 1859. THREE-QUARTER PLATE—A three-quarter plate watch is one in which there is a piece cut out from the top plate large enough to permit the balance to rotate on a level with that plate. It is the most common form at present in use in both cheap and high grade watches, and found in both "pillar" and "bridge" models. TIME-CANDLES—Candles in alternate black and white sections were used to mark the passage of time in Europe and Asia for a long time. In England and France they were used to limit the bidding at an auction. The phrase "by inch of candle" meant that the one bidding when the flame expired was the successful bidder. King Alfred is said to have used time-candles and to have inclosed them in thin horn plates to protect them from drafts, thus originating the lantern. [Illustration] TIMEKEEPER—Any device primarily concerned with measuring and indicating the sub-divisions of the day. TOMPION, THOMAS—"The father of English Watchmaking." Born 1638. He was the leading watchmaker at the court of Charles II. He found the construction of the time-keeping part of watches in a very indifferent condition and he left English clocks and watches the finest in the world, although many great improvements were made after his time. He associated closely with such scientists as Hooke, and Barlow, and made practical application of their theories—two notable instances being the cylinder escapement and the balance-spring. Tompion was the first to number his watches consecutively for the purpose of identification though he did not so mark his early ones. There is a famous clock in the pumproom at Bath, England, of Tompion's construction. Little is known of his domestic life but he appears to have been unmarried. He died in 1713 and is buried in Westminster Abbey. Tompion was master of the Worshipful Clockmakers' Company in 1704. TOP PLATE—The plate in a watch farthest from the dial. In full plate watches it is circular; in three-quarter plate or half-plate watches a part is cut away. [Illustration] TOWER OF THE WINDS—An octagonal tower north of the Acropolis of Athens spoken of as horological by Vario and Vitruvius. Believed to have had a sundial on each of its eight faces and to have contained a clepsydra fed by a spring. TRAIN—The toothed wheels of a watch or clock which connect the barrel or fusee with the escapement. In a going-barrel watch the teeth about the barrel drive the center pinion which drives the center wheel and then in turn the third wheel pinion, third wheel, fourth wheel pinion and fourth wheel, escape pinion and escape wheel. TRIPPING—The running past the pallet's locking face, of an escape wheel tooth.