With the opposite shore lost Montcalm had now no means of keeping Wolfe at any distance. But Montcalm had chosen his position with skill, and it was so strong by nature that it might yet be held till the autumn, if only he was allowed to defend it in his own way. His left was protected by the Montmorency river, narrow, but deep and rapid, with only two fords, one in thick bush, where the British regulars would have least chance, and another at the mouth, directly under the fire of the French left. His centre was the six miles of ground stretching towards Quebec between the Montmorency and the little river St Charles. Here the bulk of his army was strongly entrenched, mostly on rising ground, just beyond the shore of the great basin of the St Lawrence, the wide oozy tidal flats of which the British would have to cross if they tried to attack him in front. His right was Quebec itself and the heights of the north shore above. Wolfe pitched his camp on the far side of the cliffs near the Falls of Montmorency; and one day tried to cross the upper fords, four miles above the falls, to attack Montcalm in the rear. But Montcalm was ready for him in the bush and beat him back. The next British move was against the left of Montcalm's entrenchments. On July 31 Wolfe's army was busy at an early hour; and all along the French front men-of-war were under way with their decks cleared for action. At ten o'clock, when the tide was high, two small armed ships were run aground opposite the French redoubt on the beach a mile from the falls; and they, the men-of-war, and Wolfe's batteries beyond the falls, all began to fire on the redoubt and the trenches behind it. Montcalm fired back so hard at the two armed ships that the British had to leave them. Then he gave orders for his army to be ready to come at a moment's notice, but to keep away from the threatened point for the present. By this means, and from the fact that his trenches had been very cleverly made by his own French engineers, he lost very few men, even though the British kept up a furious fire.