On May fourteenth began what has been justly considered one of Bonaparte's most daring and brilliant moves. Even at the present day and after extensive improvement of grade, the road over the Great St. Bernard is for a long stretch barely passable for wheeled vehicles; it was then a wretched mule-track, more like the bed of a mountain torrent than a highway, and at that season of the year storms of snow and sleet often rage about the hospice and on the higher reaches of the path. The First Consul had carefully considered the great outlines of his strategy; the detail had wisely been left to able lieutenants. One by one the successive divisions, with that of Lannes at the front, climbed the steeps, crossed the yoke, and passed down on the other side to Aosta. There was, of course, some snow, and there was in any case no track for the gun-carriages; the cannon were therefore dismounted, laid in sledges of hollowed logs, and dragged by sheer human force along the rough highway. The passage into the upper vale of Aosta was commonplace enough, and on the sixteenth the head of Chabran's column also arrived there safely by way of the Little St. Bernard. But every enterprise has its crisis. Lower down, on an abrupt and perpendicular rock, was Fort Bard, which entirely controlled the valley. It proved to be impregnable. Lannes hesitated for a day. Berthier wrote him that the fate of Italy, perhaps of the republic, hung upon its capture. This proved to be a pardonable exaggeration. The French van took a rude mountain-path which lay to the northward over Monte Albaredo, and, leaving their artillery behind, advanced, or rather climbed across, toward Ivrea. Bonaparte himself came up two days later, and, hearing that Melas had now left the Var, ordered the path to be improved. Lannes, in the interval, attacked Ivrea, but failed for want of cannon. Marmont, the chief of artillery, could not wait for the engineers to complete the new road, but, wrapping all his wheels in hay, and strewing the streets of the hamlet at the foot of Fort Bard with dung, carried all the guns safely past under cover of night. The Austrians could not fire in a plumb-line downward, and, though aware of the movement, they were helpless. The garrison held out for a time, but surrendered on June first. Ivrea fell at once; the three thousand Austrians in the valley were scattered; and the Italian plains lay open to the daring adventurers, many of whom, having once outflanked the Alps under the same leader, had now attacked and surmounted them. Their enemy was first incredulous, then surprised and undecided; his forces were so scattered that it seemed as if he could no longer hold Tortona. Should that fortress fall into French hands, Genoa could be promptly relieved.