Many of the baggage animals thus perished; but at last the head of the column found itself at the foot of the steep descent in a ravine with almost perpendicular walls, amid whose foot was in summer occupied by a mountain stream.  Into the depth of this ravine the rays of the sun never penetrated, and in it lay a mass of the previous year’s snow which had never entirely melted, but which formed with the water of the torrent a sheet of slippery ice.

The newly formed snow prevented the troops from seeing the nature of the ground, and as they stepped upon it they fell headlong, sliding in their armour down the rapidly sloping bed of ice, many dashing out their brains or breaking their limbs against the great boulders which projected through it.  The cavalry next attempted the passage, but with even less success, for the hoofs of the horses broke through the hard upper crust of the old snow and the animals sank in to their bellies.  Seeing that it was impossible to pass this obstacle, Hannibal turned back the head of the column until they reached the top of the ascent down which they had just come.  There he cleared away the snow and erected a camp; all the infantry were then brought down into the pass and set to work to build up a road along the side of the ravine.

The engineers with fire and explosives blasted away the foot of the cliffs; the infantry broke up the rocks and formed a level track.  All night the work continued, the troops relieving each other at frequent intervals, and by the morning a path which could be traversed by men on foot, horses, and baggage animals was constructed for a distance of three hundred yards, beyond which the obstacle which had arrested the advance of the army did not continue.

The cavalry, baggage animals, and a portion of the infantry at once continued their way down the valley, while the rest of the infantry remained behind to widen the road sufficiently for the elephants to pass along.  Although the work was pressed on with the greatest vigour it needed three days of labour in all before the elephants could be passed through.  The animals were by this time weak with hunger, for from the time when they had turned aside from the valley of the Isere the Alps had been wholly bare of trees, and the ground being covered with snow, no foliage or forage had been obtainable to eke out the store of flour which they carried for their consumption.  Nor was any wood found with which to manufacture the flat cakes into which the flour was formed for their rations.

The elephants once through, the march was continued, and, joining the troops in advance, who had halted in the woods below the snow level, the column continued its march.  On the third day after passing the gorge they issued out on to the plain of the Po, having lost in the fifteen days’ passage of the Alps great numbers of men from the attacks of the enemy, from the passage of the rapid torrents, from falls over the precipices, and from cold, and having suffered still more severely in horses and baggage animals.