1851 Great Exhibition: Official Catalogue: Class X.: E. Greaves
503. GREAVES, E., 56 South Street, Sheffield — Manufacturer.
AEolian pitch pipes, German silver, electro plated, and gilt, in sets of 4 for violin, 6 for guitar, 8 for harp key E flat, 8 for the diatonic, and 13 for the chromatic.
AEolian violin mute, a combination of pitch pipe and mute.
Chromatic coolian pitch pipe, one vibrator sounding 13 semitones.
[The natural key of the old single-action harp is E flat, and of the double action C flat. The mute is a small instrument which is fixed on the strings of a violin, over the bridge, to soften and thin the tone. The uncertainty which at present exists with regard to the pitch is a source of great annoyance. The modern pitch varies half to a whole tone sharper from that used in the time of Handel.—H. E. D.]
Blued steel sostenuto tuning-forks, philharmonic and Wilhelm's standard pitch; Lilliput size, in case, philharmonic pitch; and French-shape, with foot and case; case of 13 tuning-forks.
Pair of chromatic tuning-forks, sounding the 13 semitones, in an octave, both equal temperament, philharmonic; and Wilhelm's standard pitch; case of amateur pianoforte tuning instruments. The chromatic tuning- forks are useful for tuning the pianoforte, etc.
Tuning-keys for horizontal and cabinet pianofortes.
Registered portable metronomes, in brass, German silver, silver, pearl, tortoiseshell, electro-plate and gild, silver, silver and pearl, silver and shell. These form a convenient substitute for the large metronome. In principle this is a variable pendulum, the tape winding up within the case, which forms the weight or bob.