+44 7831 561042

A Routledge Engineer's Rule.

hover over image to zoom

A Routledge Engineer's Rule; a two-foot, two-fold boxwood rule with a brass hinge and steel end-pieces and marked with his name and 'Bolton' to the calculating side and Davis Option Derby (retailer) to the ordinary side. English circa 1815.

Little is known of Routledge’s early years. The third of ten children, he came from a Yorkshire family, his father being a blacksmith. From 1800, Routledge is recorded as the manager at the Round Foundry in Leeds. Clearly a clever man and somewhat self taught, he had learned the value of logarithms and thereby had the means of developing a method of measuring "all kinds of metals and other bodies" needed for engineering purposes. Using the principles of Edmund Gunter's logarithmic scales and William Oughtred's sliding rule, (both from the 17th century), Routledge combined a 12-inch brass slide, containing the logarithmic scales, with an ordinary 2-foot ruler to which he added a table of commonly used references called gauge points. Patented in 1813, this rule became known as the Routledge Engineer's Rule.

Item Code: 3339

£ 125

Enquire about this item