Principal Riddell retirement book A book presented to John Robertson Riddell in April 1939 who was principal of London School of Printing for 27 years from 1912-1939. The book is embossed with 1912-1939 and his initials on the cover, inside staff and students have signed small pieces of paper with their job role and they have been stuck into the book. Riddell had been Principal at the school's predecessor the St Bride Foundation Printing School and continued on after the school has fallen under London County Council jurisdiction in 1922. Apr 1939