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Alexander William Stewart (1865 -1933), the technical and managing director of Thermotank
1865 Born Peebles, son of William Stewart, coal master, and his wife Isabella nee Sinclair.
Born and brought up in Glasgow
1891 Living in Old Kilpatrick, Dunbartonshire: William Stewart (age 50), coal merchant. With his wife Isabella Stewart (age 49), and their six children; Christina Stewart (age 26); Alexander (age 25), electrical engineer; Helen M. Stewart (age 22); Ida S. Stewart (age 20); William M. Stewart (age 17), apprentice electrical engineer; and Frederick C. Stewart (age 13).
1894 Member of Institution of Electrical Engineers, living in West Glasgow
1901 Electrical engineer living with his mother and father in Old Kilpatrick, Dunbartonshire
1922 Freeman of the City of London; living at 8 Lancaster Crescent, Glasgow
1933 Died, Glasgow. Of 8 Lancaster Crescent and Craigownie Castle
Obituary 1933 
THE great progress made in recent years in the ventilating and heating of ships, railway carriages, public buildings and aeroplanes, owes much to the work of Alexander William Stewart, the technical and managing director of Thermotank, Ltd., of Govan, Glasgow, who died in Glasgow a little over a week ago. Almost up to the last Mr. Stewart continued to take an active part in the business, which he founded in 1900, along with his two brothers, and which now has branches in many countries.
Mr. Stewart was born and educated in Glasgow, and was first prizeman in naval architecture of his year. He spent some time under Mr. Biles, now Sir John Biles, at the Clydebank yard of J. and G. Thomson, which later become John Brown's yard, where as manager of the electrical department he had much to do with the early application of electricity to ships. His own experience at sea convinced him of the necessity of combining heating with ship ventilation, which combination was an essential principle of the Thermotank system which he designed and developed.
From modest beginnings in 1900 the business extended, and Mr. Stewart lived to see his invention adopted in practically all the important ships of the world. During the war Mr. Stewart designed the Thermotank inductor, which enabled large volumes of poison-laden air to be dealt with without danger. Another invention was the punkah louvre ventilator, which found application in both naval and mercantile ships, and in the ventilation of public buildings, railway carriages, and aeroplanes. More recently he interested himself in the design and production of an axial flow type of fan for large volumes of air or gas.
Mr. Stewart was a member of the Institution of Naval Architects, the Institution of Electrical Engineers, and the Institution of Shipbuilders and Engineers in Scotland.