motor-cars are available to follow up the aeroplanes. They carry a yellow flag are exempt from the ordinary police road control. In camps & billets a bell is run on approach of hostile aircraft. For purposes of recognition, besides the ordinary marks German aeroplanes carry light balls throwing out a cluster of white stars.

BC Archives, MS-0392 / FRANK SWANNELL PAPERS Box 1 / Diary and enclosures, 1915. Volume 4