Vintage Otis King Model L Cylindrical Slide Rule Calculator Serial Number S5489

A vintage Otis King Model L cylindrical slide rule calculator manufactured by Carbic Limited, London. This mechanical calculating instrument features a telescopic chrome-plated metal body with a central black textured sleeve grip. The device operates via two rotating and sliding cylinders covered in spiralled logarithmic scales, providing greater precision than standard linear slide rules. The scales are marked Otis King’s Patent and Copyright. The top cap is embossed with Made in England and the base cap is stamped with the serial number S 5489. The calculator is housed in its original dark blue textured cardboard slipcase, which features a green paper label identifying the model as L and the serial number. The lot is further accompanied by its original printed instruction sheet from Carbic Limited, 54, Dundonald Road, London S.W.19.