Understood to be a captured First World War German Howitzer, installed temporarily in Victoria Park after delivery by the war office in the late summer of 1919. The aircraft appear to be Westland Wallaces - the type being coincidentally used February 1935 to May 1937 by No. 504 (county of Nottingham) Squadron at RAF Hucknall, possibly on the annual 'Empire Air Day' in the 1930s.