Charles Horace Mayo, together with his fellow surgeon and older brother William, were the leading founders of the famous Mayo Clinic, instituted in Rochester, Minnesota in 1919. Charles was born in Rochester the son of Doctor William Mayo, an immigrant from England. Educated at Northwestern University, the non-profit clinic made his family the most famous physicians in American history. He died of pneumonia in May 1939, aged seventy-three. (By John Osborne)