Ernest Swinton proposed the idea of the armored tank in 1915 to withstand bullets on the battlefield, helping the Allies win the war. Chlorine gas was a deadly substance used by the Germans in 1915 that would burn soldiers and lead to a slow death. Antiaircraft weapons fired at planes from the ground up to a range of 3,000 yards. As new weapons were developed and countries allied, the economy declined due to the increasing costs of the weapons and replacing destroyed ships and armies.