![An [?]18th-Century circular ivory calculator,](https://www.christies.com.cn/img/LotImages/2001/CSK/2001_CSK_09290_0111_000(040157).jpg?w=1)
细节
An [?]18th-Century circular ivory calculator,
unsigned, comprising two discs revolving against one another, the upper with graduations stamped on the side A, 12, 2-9, 1, turning against the edge of the lower disc graduated identically, but marked B, the upper surface of the instrument numbered around the outside in fractions 1/16-1, with eigths and quarters where appropriate, an inner band numbered from in 6¼ divisions up to 100, the underside of the instrument numbered 1-12 around the outside, numbered around the inside in 8 5/16 divisions up to 100, the two halves connected by and revolving around a brass screw -- 2in. (5.1cm.) diameter
See Colour Illustrations
unsigned, comprising two discs revolving against one another, the upper with graduations stamped on the side A, 12, 2-9, 1, turning against the edge of the lower disc graduated identically, but marked B, the upper surface of the instrument numbered around the outside in fractions 1/16-1, with eigths and quarters where appropriate, an inner band numbered from in 6¼ divisions up to 100, the underside of the instrument numbered 1-12 around the outside, numbered around the inside in 8 5/16 divisions up to 100, the two halves connected by and revolving around a brass screw -- 2in. (5.1cm.) diameter
See Colour Illustrations
注意事项
No VAT will be charged on the hammer price, but VAT at 17.5% will be added to the buyer's premium which is invoiced on a VAT inclusive basis.