Bidspirit auction | An Otis King's Patent Cylindrical

An Otis King's Patent Cylindrical Slide Rule Calculator with Original Box and Instructions - This lot features a vintage Otis King's Patent cylindrical slide rule, a precision calculating instrument manufactured by Carbic Limited, London. The device is constructed from chrome-plated metal telescopic tubes with helical logarithmic scales printed on a cream-coloured ground. It features a central sliding cursor finished in matte black. The instrument is accompanied by its original two-piece black textured cardboard telescope-style storage box and an original double-sided printed instruction manual. The manual includes the text Otis King's Patent CALCULATOR and identifies the maker as Carbic Limited of 4, Dundonald Road. The scales show detailed black printed numerical graduations with directional arrows labelled TOP ARROW T and BOTTOM ARROW B on the cursor mechanism. Length (closed): Approximately 15 cm Length (extended): Approximately 25.5 cm.