All night the sentries on picket duty along the allied lines watched the flames extending and the light growing in intensity. Occasional explosions from the midst of burning areas showed that General Wood had been correct in his suspicion that deadly mines lay in wait for any who might try to extinguish the conflagration. At daybreak he reported the condition of affairs to General von Blücken. The commander approved his action, but ordered several of the smaller vessels to reconnoitre immediately the Hell-Gate passage of the East River and report if that route was practicable for transports or war-ships. Admiral Seymour had anticipated the need of this knowledge the moment the burning and abandonment of the city was reported to him, and at the earliest dawn three small vessels--two of them tugs and one a light-armored cruiser--had pushed through the Gate and descended safely as far as Blackwell’s Island. Their report was brought to General von Blücken by Admiral Seymour in person, shortly after seven o’clock in the morning. A force of seventy-five thousand men was instantly ordered to embark and to proceed down the river to the Battery. If that was deserted, they were to push across the Hudson and attempt a landing on the New Jersey shore. Before the transports started, about twenty-five of the lighter-armored and swifter of the fighting vessels in the fleet steamed in advance down the narrow East River to clear the way and draw the fire of any of the enemy who might still linger in their retreat. At the same time a slow and cautious advance was made by the army from the North directly upon the burning city. It was soon found that the entire upper half of the town was in hopeless ruins. But as morning approached, the retreat had become more of a flight, and less time had been left the hurrying revolutionists to devote to destruction. All through the lower half of the city buildings were found on fire, but there had been no such universal incendiarism as had caused the obliteration of every structure above Central Park. No apparatus for putting out fires had been left in working order in the city; but by the demolition of surrounding buildings the allies succeeded in confining these detached conflagrations to narrow limits, within which they eventually burned themselves out. The revolutionists made no stop at Jersey City on their retreat. They knew that in a very short time it would be under the guns of the allied fleet. They had been compelled to abandon all their artillery except a few batteries of field-pieces, and could make no reply that would be felt within the iron sides of the armored vessels. Picking up the detachments which had been left along the west shore to watch the loyalists at Newburg, they pushed on towards Philadelphia.