Dowson and Mason Gas Plant Co
of Alma Works, Levenshulme, Manchester
1887 Dowson Economic Gas and Power Co. was established.
1905 Mason Gas Power Co was formed.
1910 These two companies were amalgamated to form Dowson and Mason Gas Plant Co and were incorporated as a limited company.
1914 Manufacturers of all kinds of gas plants and gas furnaces. Specialities: Dowson gas power plants for bituminous coal, anthracite, coke, charcoal and other fuels; Duff gas producers for furnaces etc.; Weardale gas furnaces for plates and bars, ship frames, annealing of wire, steel casting, malleable casting, tin plate and sheet. 
1922 Lord Invernairn was a director
1961 Manufacturers of industrial furnaces and ovens and burner equipment. 180 employees.