Musical transposition calculator in circular slide-rule form

1840-1880 in United Kingdom

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Musical transposition calculator in circular slide-rule format, plus key, in velvet-lined fishskin case, unsigned, United Kingdom, 1840-1880

The first is by J Wilson and is dated 1820. The second is not signed and dates from the mid 19th century. Because all the notes in a scale have a fixed frequency ratio, music can be ‘transposed’ up or down the various keys. These little devices are like circular adding machines; moving the tonic, or fundamental note, a certain number of tones up or down moves all the notes in the scale by the same interval, so music can be rewritten in a different key. The second calculator has the tonic at the top and reveals the notes in the appropriate major scale.


Object Number:
balsa (wood), brass (copper, zinc alloy), fish skin, leather, pine (wood) and velvet
overall (closed): 15 mm x 60 mm x 73 mm, 60 mm, .081kg
slide rule
  • furnishing and equipment
  • tools & equipment
  • calculator
  • furnishing and equipment
  • tools & equipment
  • calculator
Trevor Philip and Sons Ltd.

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