422 On the Temperament of Instruments with Fixed Tones, [June 16, 

 Duplex Finger-board. 



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Concurs 

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D . H 11 



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Let the black and white manuals remain as at present, and let a yellow 

 manual, of the same form as the black, be introduced between B and (7, and 

 jE' and F. Cut out about the middle third of each black and yellow manual, 

 up to half its width, on the right side only, and introduce a thin red manual 

 rising as high above the black or yellow as these do above the white. Over 

 G^, Ai and D, each of which lies between two black manuals, introduce three 

 yellow metal manuals (lacquered or aluminium-bronze) shaped like flute 

 keys, and standing at the height of a red manual above the white one, which 

 can therefore, when necessary, be reached below it. The 7 white manuals 

 are the 7 naturals ; the 5 black manuals are the 5 usual sharps, eft d% 

 g% a% ; the 2 long yellow manuals are the unusual sharps eft and the 3 

 metal yellow manuals are the double sharps /x gx cx ; and the 7 thin 

 red manuals are the 7 flats, cb, c?b, eb,/t7, ^7, «b, Sb. The shapes of the 

 red and metal manuals were suggested by those of General T. Perronet 

 Thompson's quarrils and Jlutals. The 24 levers opening the valves on the 

 organ or harmonium would lie side by side, being made half the width of 

 those now in use, and metallic, if required for strength. The organ pipes 

 or harmonium reeds would be arranged in two ranks of 12 for each octave, 

 the first rank containing the 7 naturals and 5 usual sharps, and the back 

 rank containing the 7 flats, 2 unusual and 3 double sharps. The use of 

 this finger-board is accurately pointed out by the ordinary musical notation 

 which distinguishes the sharps from the flats, and is therefore in no respect 

 adapted to the Hemitonic fusion of sharps and flats into mean semitones. 



