Howard McMahon; Physicist Was 75

Howard O. McMahon, a scientist and inventor who formerly headed the management consulting firm of Arthur D. Little Inc., has died in Cambridge, Mass. He was 75.

McMahon died Aug. 5 of heart disease.

An expert in low-temperature physics and chemistry, the Massachusetts Institute of Technology graduate joined Little as a researcher in 1943. He became vice president for research and development in 1956 and served as president from 1964 until his retirement in 1977.

In 1951, McMahon received the Edward Longstreth Medal of the Franklin Institute for his work on the Collins Helium Crystal, which liquefies helium gas at minus 452 degrees Fahrenheit.

A year later he was given the Frank Forrest Award by the American Ceramics Society for his research in thermal radiation.

Among McMahon’s patents was one for a popular bubbling candle for Christmas trees, which he developed when he was a student. Needing money for college, he sold the invention to a Canadian neon sign company for $100.

Following his retirement from Little, McMahon founded the Helix Technology Corp., a manufacturer of cryogenic refrigeration systems.