Soldiers Wearing Gas Masks

Gas warfare, first used by the Germans in 1915, involved attacking the enemy with large amounts of an asphyxiating gas. Gas attacks were somewhat limited by the unpredictability of favorable conditions. In order for a gas attack to be successful, a steady breeze of 5 miles per hour without rain had to be blowing toward the enemy. The gas had to be heavier than air and sprayed in the direction of enemy lines or fired in shells or bombs. If the wind was to strong the gas would be carried past the enemy. If the wind was not strong enough the gas may recede back on to the attackers. When successful, gas attacks could clear an entire trench and allow the attacking army to advance into enemy territory. However, a major risk of gas warfare was the possibility that clouds of the deadly substance could be carried by unexpected winds to local towns and kill innocent civilians.
Soldiers protected themselves from the deadly affects of these gases by wearing gas masks. The gas mask contained respirators that filtered the gas to provide breathable air for the soldiers. A siren sounded to alert soldiers of the launch of a gas attack. The gas cloud was usually effective for a 3 or 4 mile radius. Soldiers had to wait for an all-clear signal from their commanders before they were allowed to remove their gas masks. An additional problem caused by gas attacks was the death of rats and other animals that infested the trenches. Soldiers had to promptly remove all such animals after a gas attack to avoid the spread of diseases carried by these animals.

Why does war require the development of new technology?

Describe the scene in the photograph and explain why this device was necessary.