Glenbrook Tunnel War One. The first was Chlorine gas which was introduced by the Germans at the Second battle of Ypres in April 1915. This was followed by the use of Phosphene Gas, also introduced by the Germans. These attacked victims' respiratory organs causing coughing and choking. The Germans used Mustard Gas, a more advanced gas, for the first time at Riga (or Yperite) in September 1917. It caused both internal and external blistering in its victims. The blistering was often delayed and remained in the ground for weeks afterwards making capture of infected trenches dangerous. Protection against mustard gas was far
Action of 25 September 1917 increase the accuracy of German artillery-fire as the British attacked. On 23 September, Crown Prince Rupprecht wrote in his diary that the higher ground at Zonnebeke and Gheluvelt was vulnerable to another British attack and that it was vital that the German counter-attack tactic did not fail again. Next day, Rupprecht wrote that he hoped that another British attack would be delayed, as the 4th Army had insufficient reserves for the whole of the active front east of Ypres. Rupprecht ordered a (methodical counter-attack) against the British flank between the Menin Road and Polygon Wood, which was longer after the