Operation
A set of levers called keys is positioned just above the surface of the barrel. Each key corresponds to one note. A rod is connected to the rear of each key. The other end of the rod is a metal pin which operates a valve within the wind chest. When the instrument is played (by turning the crank), offsets on the crank shaft cause bellows to open and close to produce pressurized air. A reservoir/regulator maintains a constant pressure. A worm gear on the crank shaft causes the barrel to rotate slowly and its pins and staples lift the fronts of the keys. This causes the other end of the key to press down on the end of the rod which, in turn, activates the valve and allows air from the bellows to pass into the corresponding pipe.
To allow different tunes to be played from one barrel, the barrel can be moved laterally to bring a different set of pins and staples under the keys. Street barrel organs usually play 7 to 9 tunes, although small organs (usually the older ones) can play up to 15 tunes. Less commonly (and usually for large orchestrions) the pinning will form one continuous spiral and the barrel will be gradually moved as it rotates so that the pins remain lined up with the keys. In this case, each barrel only plays one long tune.
Read more about this topic: Barrel Organ
Famous quotes containing the word operation:
“An absolute can only be given in an intuition, while all the rest has to do with analysis. We call intuition here the sympathy by which one is transported into the interior of an object in order to coincide with what there is unique and consequently inexpressible in it. Analysis, on the contrary, is the operation which reduces the object to elements already known.”
—Henri Bergson (1859–1941)
“It requires a surgical operation to get a joke well into a Scotch understanding. The only idea of wit, or rather that inferior variety of the electric talent which prevails occasionally in the North, and which, under the name of “Wut,” is so infinitely distressing to people of good taste, is laughing immoderately at stated intervals.”
—Sydney Smith (1771–1845)
“Waiting for the race to become official, he began to feel as if he had as much effect on the final outcome of the operation as a single piece of a jumbo jigsaw puzzle has to its predetermined final design. Only the addition of the missing fragments of the puzzle would reveal if the picture was as he guessed it would be.”
—Stanley Kubrick (b. 1928)