Napier Bones: reckoning rod for multiplications

around 1700

This model of the Napier Bones is from the 18th century and belonged to Earl of Stanhope in Chevening, Kent. This set was likely used by the 3rd Earl, Charles Stanhope (1753-1816). As Viscount Mahone, he developed several four-species and one two-species reckoning machine (see Inv.-nr. FDM 9395) between 1774 and 1780. Der rods, the small placement-table and the casket with minor damage are made from boxwood. The set contains ten rods and one three-parted block for reckoning with fractions or roots. The casket is, much like similar ones (for example in the British Museum in London or the Whipple Museum in Cambridge), decorated with a linear, geometric ornament ( a six-pointed star, which is edged by several rings). For reckoning with the Napier Bones see Inv.-nr. FDM 8942.