During 1919, the distribution rights for the KLG Sparking Plug were purchased from Kenelm Lee Guinness. Smiths purchased 75 per cent of Ed. Jaeger (London) Ltd in 1927 (which became British Jaeger Instrument Company in 1932). Also in 1927, Smiths purchased the KLG Sparking Plug Company (Robinhood Engineering). The Jackall hydraulic jacking system was manufactured from 1935 by Smith's Jacking Systems and immediately became standard equipment in many popular cars. In 1937, a separate aircraft and marine department was created in the parent company and named Smiths Aircraft Instruments. It operated with Smiths subsidiary Henry Hughes and Son, who manufactured various instruments for the aviation and marine markets.