Six Marks #6

WW2Central Communications Building & Staff Office,Wee Fea, Lyness. Caricature “Prof Joad”. Pencil on whitewash. This lifelike cartoon is only10mm across. CEM Joad was a prominent socialist and pacifist who was well known as an author and broadcaster. He was chair of the National Peace Council from 1937 to 1938. After the outbreak of WW2 he abandoned his pacifism and became a key contributor to the hugely popular BBC Radio discussion programme The Brains Trust. What was the motivation of the person who left this tiny image in an inconspicuous corner of the room shown below?