of cover from view or fire.

The artillery was no doubt concealed in the woods behind. The men were
doing their work with a quick, noiseless efficiency that would have made
you very proud if you could have seen them.

Soon after the Column had passed into the woods, the noise of the guns
was heard. The Subaltern could imagine the whole scene as vividly as if
he could see it: the van-guard of the German Advanced Guard suddenly
"held up" by the bursting of the British shells; the hasty deployment of
the German cavalry; the further "holding up" of the main-guard of the
Advanced Guard while a reconnaissance was being carried out with the
help, perhaps, of a "Taube." Remember that the Germans must have been
daily, almost hourly, expecting the Allies to make a determined attempt
to check their continued advance, and must have been very nervous of
walking into some trap. Therefore the Commander of the German Advanced
Guard would have to discover very exactly the nature of the resistance
in front of him before the Officer commanding the main body--some miles
behind, of course--could decide what force it would be necessary to
deploy in order to dislodge the enemy from his position.

This is no easy matter. What the retreating army is fighting for is
time--time to get clean away. Consequently, if the Officer commanding
the advancing army deploys a larger force than is necessary, he grants
his opponent the very thing that he wants--time, since the deployment
of, say, a Division is a very lengthy operation, occupying at least
three hours. On the other hand, if he details too small a force for the
work, his attack is held in check, and more time than ever is wasted in
reinforcing it in a measure sufficient to press home the attack.