construction of such instruments and rolls, it is enough to say that they are what has become familiar to the public in the form of mechanical attachments to pianos, such as the pianola, and the musical rolls consist of perforated sheets, which are passed over ducts connected with the operating parts of the mechanism in such manner that the same are kept sealed until, by means of perforations in the rolls, air pressure is admitted to the ducts which operate the pneumatic devices to sound the notes. This is done with the aid of an operator, upon whose skill and experience the success of the rendition largely depends. As the roll is drawn over the tracker board the notes are sounded as the perforations admit the atmospheric pressure, the perforations having been so arranged that the effect is to produce the melody or tune for which the roll has been cut.
Speaking in a general way, it may be said that these rolls are made in three ways. First. With the score or staff notation before him the arranger, with the aid of a rule or guide and a graduated schedule, marks the position and size of the perforations on a sheet of paper to correspond to the order of notes in the composition. The marked sheet is then passed into the hands of an operator who cuts the apertures, by hand, in the paper. This perforated sheet is inspected and corrected, and when corrected is called “the original.” This original is used as a stencil and by passing ink rollers over it a pattern is prepared. The stenciled perforations are then cut, producing the master or templet. The master is placed in the perforating machine and reproductions thereof obtained, which are the perforated rolls in question. Expression marks are separately copied on the perforated music sheets by means of rubber stamps. Second. A perforated music roll made by another manufacturer may be used from which to make a new record. Third. By playing upon a piano to which is attached an automatic recording device producing a perforated matrix from which a perforated music roll may be produced.
It is evident, therefore, that persons skilled in the art can take such pieces of sheet music in staff notation, and by means