CLOCK, GRANDFATHER'S OR LONG-CASE—A tall clock with an anchor escapement popular thru-out the later 18th and early 19th centuries in England and America. Its excellent timekeeping qualities are due to the very long and heavy pendulum which allows a small arc of vibration. Not often made at present. [Illustration] CLOCK, HOOD—A style of clock originating and very popular in Holland during the late 17th century. Made of various woods, carved and ornamented and named from the hood or dome on top. CLOCK, LAMP—A long glass tube upright on a metal stand similar in shape to the old Roman lamps. Figures were painted on the tube to indicate the hours—"12" in the middle section, with "11" above and "1" below the "12." The lamp was filled with oil up to the hour at which it was lighted—then as the oil burned away the time was indicated. This form of clock was used at night in Dutch and German rural homes until a comparatively recent date. [Illustration] CLOCK, LANTERN—Same as Bird-Cage Clock. CLOCK, LARGEST IN WORLD—The Colgate clock in Jersey City is claimed to be twice as large as the next largest clock in the world. Its dial can be read for four miles and weighs six tons. Its minute hand is twenty feet long and the tip of it travels more than half a mile per day. [Illustration] CLOCK MYSTERIES—Glass Dial—A perfectly transparent dial behind which no movement was visible. The hands were caused to revolve by watch works and semi-circular weights in the counterpoise of the hands. CLOCK, OLDEST IN AMERICA—A clock owned by the Philadelphia Public Library—over two centuries old. It was made in London and is said to have been owned by Oliver Cromwell. CLOCK, SHEEP'S-HEAD—A clock similar to the bird-cage or lantern clock in which the dial face projects an inch or two beyond the frame. CLOCK, SKELETON—A clock whose works are covered with glass as a protection from dust, but are without a case, the works being exposed to view. There are eight skeleton clocks in the Charles Mifflin Hammond collection at the Essex Institute in Salem, Massachusetts. CLOCK, TURRET—A large clock in which the dials are distinct from the movement. Because of the exposure of the hands to the wind and snow, of the clock to dust and dirt, and of the oil to freezing temperature, turret clocks to keep time must be fitted with some device to obtain a constant force on the pendulum. The first used was the remontoire but since the invention of the gravity escapement for the Westminster clock by Sir Edmund Beckett this has been used instead. [Illustration] CLOCK, "WAG ON THE WALL"—A wall clock typical of the North of Holland in which weights and pendulum hung below the clock case, entirely unenclosed.