He kept a miniature set of traffic lights to control lengths of speakers, switching to red when they became dull or prolonged.[1][9] Charles Singer 1922–1924 Sir Arnold Chaplin[10] After studying at St. Bartholomew's Hospital Singer's primary appointment was at the City of London Hospital for Diseases of the Chest, where he remained for the next twenty-nine years. He co-authored the textbook on Fibroid Diseases of the Lung, and The Science and Art of Prescribing and wrote The Illness and Death of Napoleon Bonaparte (1913). He loved old books and prints, and became Harveian Librarian at the Royal College of Physicians.[10][11] 1924–1926 John Davy Rolleston[12] An original member of the Section, he was a member of the council, secretary and president.[13] 1926–1928 Walter G. Spencer[14] Known as "The Historian of Westminster" by fellow medics 1928–1930 Herbert R. Spencer[15] Obstetrician who wrote about William Harvey, midwifery and external cephalic version.[15] 1930–1931 Sir Humphry Rolleston[16] 57th president of RSM.[16] Humphry Rolleston