The annexed illustration shows a cross section of an ordinary barrel organ, a is the barrel, 'set' round its circumference with 'pins,' at the various intervals, and of the various lengths, necessary for the music, and turned by the worm b on the shaft c; d d are the bellows worked by the cranks e e on the shaft and the connecting rods f f, and delivering the wind into an air chamber g, which runs to the further end of the case, and is kept at a uniform pressure by the spiral springs h h. The air vessel again delivers the wind into the wind-chest m, which communicates with the pipes n n. Each pipe has its valve o, which is kept closed by a spring until the corresponding pin on the barrel raises the trigger p, and forcing down the connecting wire r, opens the valve and admits wind to the pipe. s s is the case. Space being very valuable in these instruments the pipes are packed together very closely, and are often bent in shape to fit the demands of the case. In the diagram one is shown lying beneath the floor of the bellows.
The barrel is made of staves, about 2½ inches wide, of the best pine wood without knots or sap, and seasoned for many years before being used. At each end of the barrel, and sometimes also in the middle, is a circular piece of hard mahogany called a barrel-head, to which the staves are glued and pegged. The barrel is then handed to the turner, who makes it perfectly cylindrical, and it is then covered with cartridge paper and sometimes painted. At one end of the barrel the 'head' is furnished with a circle of teeth for the worm connected with the handle to work in when slowly rotating the barrel. Projecting from this 'head' is the notch-pin. The number of notches in the pin corresponds to the number of tunes played by the barrel. A knife lowered into the notch prevents the barrel from shifting its position. The simplest arrangement is for the barrel to play a tune completely through in the course of a single revolution.
The keys are usually 7-8ths of an inch apart, and the intervening space upon the barrel may be filled either with pins for producing fresh tunes to the number of nine or ten, or with a continuation of the original piece lasting for the same number of revolutions of the barrel. In the latter case the 'notches' are arranged in a spiral so as to allow the barrel to shift horizontally to left or right at the end of each revolution without the intervention of the hand.
It is not within the scope of this article to speak of the players of the street organs, but it may be mentioned that there are some four 'masters' in London, employing from 30 to 50 men each, to whom the organs are let out on hire. The number of organs sold for use in London alone by the house already named is about 30 a year, but the export trade to the West Indies, Brazil, etc., is also considerable.Barrel organs have been made with three and four barrels in a circular revolving iron frame. The first of the kind, containing four barrels, was made by Mr. Bishop, sen., the father of the present organ-builder of that name, for Northallerton church, Yorkshire, about the year 1820. Many years later Messrs. Gray and Davison made grinder organs with three barrels in one frame.
[ E. J. H. ]
[ F. G. ]
[ W. H. H. ]
[ M. C. C. ]