Peel’s heavy guns were swung round, and opened in fierce duel with the enemy’s battery firing on the bridge. One of the first shots fired from one of Peel’s 24-pounders struck the gun which Nana Sahib had at last got to bear upon the bridge, and dismounted it. An 8-inch shell next dropped amongst a crowd of his troops, and they quickly fell back. Then the British troops commenced to file across the river, still under the fire of the enemy. The enemy’s advance batteries were quickly driven back, and the great convoy began to creep over the bridge. For thirty-six hours the long procession of sick and wounded, of women and children, of guns and baggage crept across the swaying bridge. On the night of the 29th, the mutineers tried to interrupt the process by sending down fire-rafts upon the bridge. Tried earlier, the scheme might have succeeded, or tried even then with greater skill and daring, it might have had some chance of success; as it was, it failed ignobly, and the endless stream of non-combatants was brought over the river into safety. Campbell, for all his fire of courage—and it may be added of temper—had an ample measure of Scottish coolness, and he kept quietly within his lines for five days till his helpless convoy had been despatched under escort to Allahabad, and was beyond reach of hostile attack. Then, with his force in perfect fighting form, he addressed himself to the task of crushing the enemy opposed to him. His own force, steadily fed by reinforcements, by this time numbered 5000 infantry, 600 sailors, and 35 guns; that of the enemy amounted to something like 25,000 men with 40 guns. Nana Sahib, with his mass of somewhat irregular troops, occupied the left wing between the city and the river; the Gwalior contingent, still formidable in numbers and military efficiency, occupied the town as a centre, and formed the enemy’s right wing, thrust out into the plain towards the canal. It was a very strong position. The enemy’s left, perched on high wooded hills, was covered with nullahs and scattered buildings. An attack on their centre could only be made through the narrow and crooked streets of the city, and was therefore almost impossible. But their right lay open to Campbell’s stroke, and if turned it would be thrust off the Calpee road, its only line of retreat.