Fifteen-Inch Howitzer, by Percy Smith, 1916-1919.

Percy Smith experienced the newest most powerful naval gun, the 'fifteen inch Howitzer'۪, popularly known as 'Granny'. His attempts at sketching the gun were met with opposition and he was reported to his superiors as such sketches were 'suspicious'۪ and considered to be tantamount to a spying activity. Successive appeals at last reached General Aston, himself interested in etching, and Percy was allowed to continue unofficially.

Image Courtesy of Percy Smith Foundation.