"Nothing can be directly done," Sir Sidney said; "but if we make a sally in force we might drive the French back, discover the mine, and carry out the greater part of the powder, and place a small portion under the ditch, and, exploding it, allow the water to run in; or, if the men carry with them a number of fascines, we might establish a work fifty yards from the foot of the wall. This would put a stop to their mining. An enemy attacking it would, as he advanced, be swept by the guns of the two men-of-war and the gun-boats, and the garrison would further be covered by the fire from the tower and walls. I propose that we should sally out in three columns. The central column, which will be composed of the marines and sailors of our ships, will make straight for the mouth of the mine and force its way in; the other two columns will attack the enemy's trenches on right and left."