solution to absorb any slight gas leakages. Three layers of
sandbags were built above the salzdecke to protect the cylinder
from shell fragments and to form a firestep for the infantry.
This concealed the cylinders so efficiently that, in our own trenches,
I have often found the new occupants of a sector ignorant
of the presence of gas cylinders under their own firesteps.
On the favourable night the dome was removed and a lead pipe
was connected to the cylinder and directed over the parapet
into No Man's Land, with the nozzle weighed down by a sandbag.
The pioneers stood by the batteries of twenty cylinders each
and let off the gas a fixed few minutes after a rocket signal,
at which the infantry retired to leave the front line free
for the pioneers, who not only ran the risk of gassing from
defective appliances but were subjected to almost immediate
violent bombardment from the opposing artillery. When surprise
was complete artillery retaliation was very late in developing.
This gives a faint idea of the elaborate preparations required.
They must have been doubly arduous and lengthy on the very first
occasion of cloud gas attack.


[1] _Die Technik Im Weltkriegre_. Publisher: Mittler, Berlin, 1920.


German Opinion of Results.--We can now regard the chlorine attack
of April 22, 1915, as the first and successful result of a huge
German experiment on a new method of war, the pioneer work
of which actually began at (if not before) the outbreak of war.
Quoting again from Schwarte: "G.H.Q. considered the attack near
Ypres to he a successful experiment. The impression created