The whole operation was very much more important than was appreciated by the British public at the time, and formed a notable example of anticipatory tactics upon the part of the German General Staff. Just as they had delayed the advance upon the west by their furious assault upon Verdun on the east, so they now calculated that by a fierce attack upon the north of the British line they might disperse the gathering storm which was visibly banking up in the Somme Valley. It was a bold move, boldly carried out, and within appreciable distance of success. Their first care was to collect and concentrate a great number of guns and mine-throwers on the sector to be attacked. This concentration occurred at the very moment when our own heavy artillery was in a transition stage, some of it going south to the Somme. Hardly a gun had sounded all morning. Then in an instant with a crash and a roar several mines were sprung under the trenches, and a terrific avalanche of shells came smashing down among the astounded men. It is doubtful if a more hellish {24} storm of projectiles of every sort had ever up to that time been concentrated upon so limited a front. There was death from the mines below, death from the shells above, chaos and destruction all around. The men were dazed and the trenches both in front and those of communication were torn to pieces and left as heaps of rubble. One great mine destroyed the loop of line held by the Princess Patricia's and buried a company in the ruins. A second exploded at Mount Sorel and did great damage. At the first outburst Generals Mercer and Williams had been hurried into a small tunnel out of the front line, but the mine explosion obliterated the mouth of the tunnel and they were only extricated with difficulty. General Mercer was last seen encouraging the men, but he had disappeared after the action and his fate was unknown to friend or foe until ten days later his body was found with both legs broken in one of the side trenches. He died as he had lived, a very gallant soldier. For four hours the men cowered down in what was left of the trenches, awaiting the inevitable infantry attack which would come from the German lines fifty yards away. When at last it came it met with little resistance, for there were few to resist. Those few were beaten down by the rush of the Würtembergers who formed the attacking division. They carried the British line for a length of nearly a mile, from Mount Sorel to the south of Hooge, and they captured about 500 men, a large proportion of whom were wounded. General Williams, Colonel Usher, and twelve other officers were taken.