though the enemy wire in the immediate vicinity of the crater would be
destroyed, the obstacle effect of the whole entanglement remained almost
in its entirety. A new fuse which was known as No. 106 was introduced in
1917, by means of which the shells would explode instantaneously on
impact, and the splinters would destroy the wire over a much bigger area
than had formerly been the case. The artillery could now ensure the proper
cutting of the enemy wire entanglements, and it had been anticipated that
in the attack of the 31st July the troops would not encounter serious
obstacles in the way of wire entanglements, particularly as they were to
be supported by tanks. It is true the artillery had cut the wire, but
several units had nevertheless been held up. The Germans had anticipated
to some extent the British methods of attack and invented a system of
defence to meet it.

The Commander of the Fourth German Army which was defending the Ypres
sector, Infantry General Sixt von Arnim, was a commander of high standing,
inasmuch as the British Higher Command had thought fit to publish some
observations of his on the Somme Battle. In the Ypres sector he had
adopted the plan of holding the forward zone with few troops well disposed
in depth, with strong reserves in rear which could be used for an
immediate counter-attack before the British could consolidate any
positions they had won. His advanced troops were carefully echeloned in
fortified farms, each strongly concreted and armed with several machine
guns. The advantage of this scheme was that it afforded few definite
targets to the British artillery, and gave every opportunity to the
Germans to ambush and enfilade advancing British infantry. Tanks were of
little avail against these block-houses, which in reality formed a belt of
small fortresses which could only be overpowered one by one. At any rate
they could easily break up the force of an attack, and inflict a large
number of casualties at a small loss. The reserves could then be used to
counter-attack the British before they had properly put the positions won
into a state of defence. Such a method of defence was indeed a difficult
obstacle to the advance, and its efficacy had been learnt at great cost in
the last fight. This system of defence meant that new tactics had to be
evolved to combat such a scheme. The German method of defence was
explained in printed sheets and the explanations were retailed to the men.
In the