Fowler's Universal Calculator

Fowler & Co. in Manchester made this pocket calculator during the early 1930’s. It was designed for engineers; draughtsman and science students with several advantages over straight slide rules. The calculator consists of a dial and two rotating knobs. The dial is synchronized with a rotating red radial hairline cursor for 6 separate circular scales. The scales are: multiplication and division, a reciprocal scale (turning counter clockwise), logarithm, cube and cube roots, squares, sines of angles and tangents of angles. The rule is marked Fowler's Universal Calculator' and 'Patent' and 'Fowler & Co. Manchester. Comes in its original green felt lined leather case signed Fowler’s Calculator. Also included is the original instruction book. Fowler's was founded in 1898 by William Henry Fowler. He was joined by his son Harold in 1905.