Wolfe's first move was to occupy Point Levi, and erect batteries there, from which he could bombard the city. His next was to occupy the ground just east of the mouth of the Montmorenci, in the hope of being able to cross that stream higher up and attack the main French camp in rear. There was no real risk in dividing his army, assuming that the force on the north bank of the St. Lawrence was sufficiently large, for the detachments on the south bank were inaccessible to the French. On July 18, some ships ran past the batteries of Quebec, a feat which the French commanders had deemed impossible. Boats were dragged overland behind Point Levi, and launched on the river above. It became necessary to detach troops to guard the long line of cliffs extending for many miles above Quebec. Still Montcalm could not be brought to risk anything by a counter stroke: a direct attack on his camp seemed hopelessly rash, but there was apparently no alternative. On July 31 an attempt was made to scale the heights a little west of the Montmorenci, which failed: the over-eagerness of the detachment ordered to lead the attack spoiled what little chance there may have been, but success was hardly possible. Then Wolfe fell ill, and for weeks nothing was done. When he recovered, if it can be called recovery for an acute attack of a mortal disease to pass away, he turned his attention in earnest to the river above Quebec. Ship after ship ran the gauntlet of the batteries, and troops were pushed up the southern bank. A large French force under Bougainville had to be employed to guard, as best they could, the long line of cliffs on the opposite shore. Several attempts at landing were made, without achieving much except wearing out the French troops with incessant marching to and fro, while the English, conveyed rapidly in boats, could threaten any point they pleased. Obviously however, it was one thing to land a party for a mere raid; it was far more difficult, under the conditions, to land the whole army, small as it was, and establish it on the high ground west of Quebec. Before he had seen the place, Wolfe had hoped to attack the city in this way: now, after proving that no other course was feasible, he reverted to this desperate venture.