light should show no impossible salients, no outlying indefensible positions, no naked flanks, and no yawning gaps. How easy are such exercises over a map upon a study table, and how difficult when conducted by dazed, {53} over-wrought officers, pushing forward their staggering, half-conscious men in the darkness of a wilderness of woods and fields, where the gleam of a single electric torch may mean disaster to all! And yet, as every morning dawned, the haggard staff-captain at the telephone could still report to his anxious chief that all was well, and his battle-line still intact between the Hun and his goal. On the morning of the battle the general disposition of the Fifth Corps had been that the Seventeenth Division (Robertson) was in the line on the left, the Sixty-third Naval Division (Lawrie) in the centre, and the Forty-seventh Division (Gorringe) on the right, being the southern unit of the Third Army, in close liaison with the Ninth Division, the northern unit of the Fifth Army. Two divisions were in close reserve, the Second (Pereira) on the right, and the Nineteenth (Jeffreys) on the left. [Sidenote: Fourth and Fifth Corps. March 21.] The Forty-seventh Division was in a particularly important position, since it was the flank unit and the liaison between the two armies depended upon it. It had only come into line the day before the battle, taking the place of the Second Division, which was now in immediate support. On March 21 the 140th Brigade covered the right of the divisional front, and the 141st the left, the sector being that of La Vacquerie. In view of the menacing attitude of the enemy both the 142nd Brigade and the 4th Welsh Fusiliers Pioneer Battalion were brought nearer to the front line. So heavy was the gas bombardment in the morning that the front battalion of the 140th Brigade, the 17th London, had to evacuate some advanced trenches and to wear their gas masks for hours on end. The front line trenches were blown {54} to fragments, and so also were many of their garrison. The following infantry advance, however, though vigorously conducted, had no great weight, and seems to have been the work of two battalions carrying out a subsidiary attack. By a counter-attack of the 19th London they were driven out once more.