Humphreys and Glasgow was established in 1892 in London to erect water-gas plants and apparatus. The firm had a successful career in consulting engineering, with Humphreys and Glasgow gas plants installed all over the world. In the 1950s and 1960s it won major contracts from the British Gas Board for plants producing gas from coal and oil. The firm ultimately diversified into petrochemical engineering. In the 1970s and following the discovery of North Sea oil and gas and a downturn in the chemical industry, business declined. Whilst the company moved successful into the offshore engineering business, it was ultimately sold to a business concern based in Dallas, Texas, in 1983.