Chemical weapons and the United Kingdom army against British and Canadian soldiers near Ypres, Belgium, in 1917 and later also against the French Second Army. The name Yprite comes from its usage by the German army near the town of Ypres. The Allies did not use mustard gas until November 1917 at Cambrai, France, after the armies had captured a stockpile of German mustard-gas shells. It took the British more than a year to develop their own mustard gas weapon, with production of the chemicals centred on Avonmouth Docks. (The only option available to the British was the Despretz–Niemann–Guthrie process). This was used first in September
Halberstadt CL.II Halberstadt CL.II The Halberstadt CL.II was a German two-seat escort fighter/ground attack aircraft of World War I. It served in large numbers with the German "Luftstreitkräfte" (Imperial German Army Air Service) in 1917-18. Early in 1917, "Idflieg", the German Army Inspectorate of Flying Troops, developed a requirement for a new type of two-seat aircraft, smaller than the existing C-type aircraft. This type, to be known as CL-type (Light C type) aircraft, were to be used to equip "Schutzstaffeln" (Protection flights) to escort reconnaissance aircraft. To meet this requirement, Halberstadt developed an aircraft based on its earlier, unsuccessful Halberstadt D.IV single-seat