'The Gun Line 'SOS'. The Salvo. Captain Gilbert Holiday, Royal Field Artillery (1879-1937). Holiday'S Early Life Was Spent In St. John'S Wood And From His Window He Was Able To Watch The Royal Horse Artillery, Which Was His First Contact With Horses. He Was Educated At Westminster And Then Studied At The R.A. Schools. He Worked As An Illustrator At The Graphic, The Tatler And The Illustrated London News. Holiday Served As A Gunner In The Royal Field Artillery On The Western Front During The First World War And He Painted Many Pictures For Army Messes.'