Stewart, Balfour

Balfour Stewart made pioneering contributions to the study of radiant heat, anticipated the existence of Earth’s ionosphere, investigated solar-terrestrial relationships, and constructed the first physical model of the solar cycle. The son of a tea merchant, Stewart was first educated in Dundee, and at the early age of 13, he entered Saint Andrew’s University. He subsequently transferred to the University of Edinburgh, where he studied natural philosophy under James David Forbes. Under parental pressure, he left the university at age 18 to undertake a business apprenticeship in Leith, which was followed by a commercial venture in Australia.