In fact, the Division was most fortunately placed. After a long experience of close contact with the enemy, it was now to be given a period in which time would be available to collect and crystallise its thoughts on the problems of defence and to be trained by General Harper in the principles of the attack. CHAPTER IV. TRAINING AND REORGANISATION--THE LABYRINTH. The Division was now out of the line for the first time under General Harper's command, and the latter lost no time in instructing officers and men in a form of attack which at the time was employed by no other Division. Past experience, emphasised by the battle of Loos, had made it evident that to hold captured ground against the inevitable counter-attack, the attackers have not only to compete with the enemy actually manning the assaulted trenches. They must, in addition, dispose themselves at the end of the advance in a manner which enables them to resist the counter-attacks which will inevitably be delivered by the enemy's reserves. In the past, the objectives of the attack had not been sufficiently clearly defined, with the result that the forward movement frequently came to an end with some bodies of troops far in advance of others, and all in a state of disorganisation. The foremost troops were thus left exposed, holding insufficiently consolidated salients, and disposed in a manner which prevented command being adequately exercised over them. The result was that the enemy was able to employ his fresh reserves against the tired and disorganised troops holding these salients. His counter-attacks, organised so as to be delivered both frontally and from the flanks, were in consequence frequently successful. It thus followed that Divisions which in the early phases of an attack had carried out a brilliant advance, were subsequently in the later stages often overwhelmed and severely cut up. It had, further, been the custom in the past for the same body of troops to be ordered to fight its way through a succession of trench lines or defended localities. Thus, as the action progressed, the attack became weaker and more disorganised through casualties, and so increasingly lost its driving power. At the same time, when the forward movement came to a standstill, no organised bodies of troops were left suitably disposed to hold the ground gained. The plan of attack adopted by the 51st Division was designed to eradicate both these sources of failure. It was realised that if counter-attacks were to be defeated, the advance must be made in a series of clearly-defined bounds. Each bound was to be made good before the operations for the capture of the next began.