Barrel
A cylindrical box made of brass or steel in which the mainspring of a watch or clock is confined. Barrels are of two general types, those with and those without teeth around their circumference. In fuzee watches the power is conveyed to the fuzee by means of a chain and from the fuzee to the center pinion by means of the great wheel on the fuzee. In American watches the barrel has teeth cut upon its circumference and gears directly into the center pinion. The latter type is generally known as the "going barrel." The going barrel is again divided into two types, one which has a support at both ends of the arbor and the other which is supported only at the upper end by the ratchet wheel. This latter form, which is sometimes termed the overhanging barrel, is generally found in repeaters and complicated watches, where economy of space is found desirable. This type of barrel is objectionable even in the very best makes of watches on account of the undue friction of the ratchet wheel and its liability to become out of upright by even the smallest amount of wear. Where this style of barrel is used, the objections may, to a certain extent, be overcome by the use of a large ratchet wheel and superior fitting. Of late years steel has taken the place of brass for barrels very largely, especially among American makers, but these barrels do not find favor among repairers as it is very difficult to replace the mainspring hook when broken. The barrel dates from about 1500, but is not as old as the main spring, for there are many examples still in existence of antique watches which had no barrel proper. This is illustrated by a watch, which is in the collection of Mr. Carl Marfels, of Berlin. In this specimen the mainspring is confined within the limits of four iron pins, and the motion is conveyed to the train through the medium of the staff and a great wheel.