Silvanus P. Thompson (June 19, 1851 – June 12, 1916) was an electrical engineer and professor of physics best known for Calculus Made Easy. He was born in York, England to a Quaker family and educated at Bootham School, where his father was a master. After graduation Silvanus was made science master at the school and soon became a lecturer and then professor of physics at University College in Bristol.  In 1878 he joined the new City and Guilds of London Institute for the Advancement of Technical Education in Finsbury and served as professor of Physics for 30 years.  He was noted for his impressive lectures and his ability to communicate difficult scientific concepts in a clear and interesting manner; radiologist AE Barclay said that: “None who heard him could forget the vividness of the word-pictures he placed before them.” He developed a method to increase the speed of submarine telegraph transmissions and took a keen interest in Rontgen Light, or x-rays, serving as first President of the Rontgen Society, later called the British Institute of Radiology. He was also the author of the physics textbook Elementary Lessons in Electricity and Magnetism and wrote biographies of Lord Kelvin and Michael Faraday.