��to believe he could also make his machine print the music executed in the ordinary notation, but avowed that this was only a project. The apparatus shown did not appear to have been in working order. In 1887 M. Charpentier took out another patent, in which metal styles attached to the under part of the keys acted on the balanced ribs of a revolving cylinder ; these were kept inked, and marked the paper as it gradually unwound. He also provided for depressing by electro-mag- nets or pneumatic agency. In 1880 Mr. H. J. Dickenson proposed to apply the principle of the Casselli electro-chemical telegraph to recording music played on the piano ; from the meagre account of his plan printed in the specification it is impossible to describe its mechanism. In 1 881, M. A. P. Hodgson, an engineer of Paris, took out a patent (No. 573) for an ' Apparatus for cor- rectly transcribing musical compositions.* The instrument is termed by the inventor the 'Piano- graph Metronome.' To judge from the specifica- tion and drawings attached to the patent, this apparatus was of the most complicated descrip- tion. The machine was furnished with a metro- nome for governing the rate of motion at which a cylinder should revolve, and so regulating the time ; this had to be mathematically exact, other- wise the mechanism would not synchronise with the player. If all went right, the machine was supposed to print on a huge band of paper about four feet broad, lines representing in their length the duration of the notes held down. As no pro- vision was made for indicating any variation of the time-measure, or for accelerandos, ritardan- dos, etc., M. Hodgson's machine would not have proved of much utility, even if it could have been constructed ; he had so little idea of music that he directed the player ' to end his compo- sition by a perfect chord in the key of F, and not by the tonic a third or a fifth/
In 1 88 1 Herr J. Fohr showed at the Stuttgart Exhibition of that year an excellent contrivance which accomplishes the object aimed at in a more complete way than before. The apparatus was exhibited in action in London, and a paper was read upon the subject by the present writer at the June meeting 1882, of the Musical Association; it is described at length in the 1881-2 volume of the society's proceedings. The machine was also shown in operation before the members of the College of Organists. The me- chanism of this Eleotro-chemischer Notenschreib- apparat is simple. The apparatus is contained in a small pedestal which may be placed at the side of a piano, and connection is made with the instrument through a cable of wires attached to a long frame resting on the keyboard of the instrument. This is furnished with a series of studs each one touching the back of the ivories and ebonies just in front of the usual name board ; these studs, by means of insulated wires, are in connection with platinum points which press on a band of paper, five inches broad, unwound from a drum by means of clockwork. The paper, as it passes through the mechanism, is saturated with a solution of ferrocyanide of potas-
si urn, ammonia, sulphuric acid and water ; it is afterwards ruled by means of an aniline inking roller with the five lines of the stave, and some dotted ledger lines are added above and below. On the pianoforte key being depressed, the circuit is completed and the current runs from a Le- clanche* battery, passing through the saturated paper by the particular style or styles in connec- tion with the keys struck, and staining it a bluish colour ; the electric current decomposing the salts with which the paper is charged. The length of the stain depends upon the time the key is held down ; a semibreve, for instance, appearing as a long streak, while a quaver would be but a dash, and a demisemiquaver a mere dot. The blank spaces on the paper represent the periods of silence ; thus, marks are formed by the passing current, and rests are indicated by its absence. The stains representing the white notes are twice as broad as those standing for the black ones MM. A pedal serves to indicate the bar lines. On depressing this (as in the ordinary mode of beating time) the position of the first beat in the bar is indicated by short double lines = stained at the moment of depression on the top and bottom of the stave. The rate of motion of the paper is governed by a sliding lever, which also serves to start and stop the clock-work arrangement. Herr Fohr's apparatus is simple in design, and the musical shorthand it produces is translateable without much diffi- culty. It is worked upon much the same plan as that of the electro-chemical telegraph of Bain. In 1872 Mr. Alexander A. Rossignol took out a patent (No. 990) for an ' Apparatus for tracing music,' and his scheme is substantially the same as that of Herr Fohr. The only modification would seem to be that M. Rossignol employed styles made of two different metals which severally stain the saturated paper red and blue, representing the black and white keys of the piano. There is no record of this instrument having been constructed. As it is stated that Herr Fohr's design dates from several years ago, since which time he has been working it out, the question as to priority of invention is uncertain. The following illustration is a reduced represen- tation of the first section of ' God Save the Queen,' as produced by Herr Fohr's contrivance ; it is in the key of A and in four parts, 3-4 time.