INSTRUCTION IN Assembly OF ROTARY MOTORS• 
merican student mechanics in a British school, are ehown studying repair and adjustment of gas engines.
Air Service, United States Army photograph
1918
National Archives of the United States via Gorrell's History of the American Expeditionary Forces Air Service, 1917-1919, Series B, Air Service Activities with the French, British, and Italians, Volume 2, History of the Air Service in Great Britain