Universität Stuttgart Abteilung Wirkungsgeschichte der Technik, page 3
At February 1915 the gas troops started the installation of the gas cylinder. Haber was at the front and supervised personally all activities. Due to the changing wind directions the gas cylinders were finally installed in the northern- and northeastern front sections. Due to the closeness to the frontline, what was often less than 50 meter away, the work could be done only at night. The installation was finished on 11 April 1915. From 14 April on it gave orders for readiness to the gas troops, which were cancelled again and again due to changing wind conditions.
On 22 April 1915, after 17.00 o'clock the wind direction was appropriate. After a short artillery bombardment, about 6000 Cylinder were opened simultaneously. 150 tons of chlorine gas has been discharged within 10 minutes on a length of 7 kilometer. Based on eye witness reports a tremendous gray-green cloud came over the French and Algerian servicemen and enveloped them. Due to the gas the service men could not respire and many of them died under great pain. Who were able to run, fled in panic and let a big gap to develop in the front line. Thereby the German infantrymen could advance till the next day by three kilometer.6
Abb.1. Drawing from John de G. Bryan shows the escape of the French soldiers at the first German
gas attack at Ypres on 22 April 1915 (from "The illustrated London News")7
A contemporary witness describes the situation:
"It is a hateful and terrible sensation to be choked and suffocated and unable to get breath:
a casualty from gunfire may be dying from his wounds, but they don't' give him the sensation
that his life is being strangled out of him".8
Martin Gutmann