Harry L Welsh spent the majority of his career at the University of Toronto. He received undergraduate and master’s degrees there, and was a professor there until his retirement. He did his Ph.D. work at the University of Gottingen, but was interrupted after only two years due to the political climate in Germany at the time. He finished this degree in 1936. After a brief position at a glass company, Welsh joined the university in the fall of 1936 as a demonstrator. During the war, he aided in the teaching of special courses for military personnel, and was promoted to Assistant Professor in 1942. In 1943, he was asked to serve with the t of Operations Research of the Royal Canadian Navy in Ottawa, which he did until the end of the war. Then, he returned to the University of Toronto, with a newfound interest in spectroscopy, for the rest of his career.

Throughout his career, he made many contributions to both scientific research, the field of spectroscopy, and the University of Toronto. As Chairman of the physics department, he expanded the faculty, built a new building for the department, and organized a Research Board to handle the growth of research. He supervised 65 Ph.D. students by 1979. Simultaneously, he continued to perform rigorous research and greatly enhanced his field.

He was widely recognized for his work. He was a Fellow of the Royal Society of Canada, the Royal Society of London, the American Physical Society, and The Optical Society. He also received numerous medals and awards, including OSA’s William F. Meggers Award in 1974.

Welsh passed away in 1984.