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Experiments made by A. Graham Bell during the Autumn of

1875 ­ Not earlier than June nor later than October 1875

  1. Circuit (g-cMd-eM2f-h) Battery power two Grove cells.
    Upon plucking S the other armature S' was thrown into vibrations. Upon placing the ear against M2 a loud musical note was perceived which was inaudible when the finger was placed upon the armature S'.
  2. The armature S' was removed and the ear placed as before against M2 Upon plucking S no sound was audible from M2
  3. Circuit (cMd-iM2f-c). No battery employed. Upon plucking S S1 could be felt to tremble. Upon placing the ear against M2 a faint musical tone could be perceived each time S was plucked.
  4. Same arrangement as last but a + b crossed so as to make a closed circuit aM'ba Sound audible at M2 as before when S was plucked.
  5. No sound audible from M2 when S' was
[PrevPage] [Next] [INDEX ]  Volume 1   October 1875   Page 5   [Source] [ NOTES ]