Collection online

instrument-case / arithmetical jewel

  • Object type

  • Museum number


  • Description

    Arithmetical jewel; ivory, partly covered in velvet; sunk gilt decoration; leather case with velvet lining; blind stamped with gilt decoration; outer leather case; rectangular block; indications engraved and filled in in black, with thin brass indexes, each rotating on pin driven into the ivory; 14 columns of entries, each with 8 thin brass rotating indexes.


  • Producer name

  • Date

    • 1616
  • Production place

  • Materials

  • Technique

  • Dimensions

    • Length: 124 millimetres
    • Width: 61 millimetres
    • Height: 8 millimetres
  • Curator's comments

    Ward 1981
    The 'Jewell' itself is a rectangular block of ivory, 122 X 58 mm, with indications engraved and filled in in black and with thin brass indexes, each rotating on a pin driven into the ivory. There are fourteen columns ofentries, headed respectively X M C X M C X m C x I S, followed by cC and β .
    Specimens of the other letters are:
    x M m C l S
    Each of the columns 1-11 has eight thin brass rotating indexes, alternately rectangular and semicircular. When a rectangular index is rotated it either covers or uncovers a figure v and each semicircle similarly uncovers one by one a series of four dots. In column 12 the smaller indexes are 60° sectors, and they cover or uncover either or both of the figures x and v. In column 13 the smaller indexes cover or uncover the figures VI (one of these indexes is missing), and the larger indexes each cover or uncover a series of five dots. In column 14 there are only four semicircular indexes and each of these covers or uncovers a series of three dots.


  • Bibliography

    • Ward 1981 220 bibliographic details
  • Location

    Not on display

  • Acquisition name

  • Acquisition date


  • Department

    Britain, Europe and Prehistory

  • Registration number



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Object reference number: MCC3600

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