etc.; and even at this moment your reporter is asking the two former questions at Fortress Monroe, without being able to obtain more than a supposition for an answer. I have said that this movement had been in contemplation some time, but the first intimation of it took place on Monday last, when McCall's division received orders to strike their tents, provide six days rations, and be ready to move at a moment's notice. At nine o'clock at night the whole division arrived at the wharf, and embarked quietly on steamers; left the Landing some time during the night for Acquia Creek, as was supposed, via Fortress Monroe. An order was next issued that no more vessels loaded with supplies should proceed further than Fortress Monroe; and on Wednesday ten days rations were served to the army, which was required to be in readiness to move at an hour's notice. All the knapsacks of those who were ordered to march by land were placed on board barges and schooners, for the humane purpose of relieving the men of their weight and incumbrance during the hot and weary march. On the same day General McClellan and Colonel Ingalls left Harrison's Landing for the nearest telegraph station, and communicated with the War Department as to future movements, returning the following day. On Thursday the army commenced evacuating in earnest. All the siege-guns were removed from the front, and safely embarked on Thursday and yesterday on board barges and schooners. Porter's corps led the van of the overland portion of the army on Thursday night. On Friday morning every tent was struck, and then, for the first time, was it generally known that the whole army was about evacuating Harrison's Landing. On Thursday night fifty sail of vessels left the different wharves, loaded with stores, and yesterday the remainder of the stores were placed on boats and steamers by the contrabands. All the cavalry that remained before the final departure of the land forces acted as pickets, and a strong rear-guard of infantry and artillery was placed to protect the baggage-trains. The sick and wounded who remained at the different hospitals were placed on board the regular steamboats belonging to the Sanitary Commission at the Long Wharf, and were among the first to move out into the stream. Contrabands were shipped on schooners, barges, and pontoon-boats, and it was an amusing sight to see the long line of boats with their ebon freight pass the different steamers and wharves, to take their places among the others anchored in the stream, or hear the questions, answers, and jokes which passed between the two parties, amid the “ha! ha's!” of the white men and the “ya! ya's!” of the black. Gen. McClellan and most of his staff went by land, and yesterday afternoon Col. Ingalls and Captain Rankin started across the peninsula on horseback. Captain Sawtelle remained to direct the operations at the Landing, and great praise is due him for his energetic and indefatigable exertions and excellent management throughout. All being now safely embarked on board the different vessels, Col. Butler, commandant of the depot-guard, called in his sentinels, who were on duty at the different wharves, and embarked his regiment on board the North-America. His regiment, the Ninety-third New-York, have performed the arduous duties of guarding the depots at White House and Harrison's Landing with credit to themselves and satisfaction to the whole army. And now they, too, are all embarked, and the last steamer has steamed to the centre of the stream, the mighty fleet quietly resting at anchor on the bosom of the placid James, waiting for the changing of the tide, which is the signal of departure. The last steamer had paddled out in the stream. This occurred about nine o'clock. The moon was about half full, shedding sufficient light to clearly distinguish surrounding objects. Up and down the river, far as the eye could reach, the fleet lay quietly at anchor, the many-colored signal-lights, bright and flickering, looked like fairy stars of various hues, flashing along the whole line. A light breeze was blowing up the river, rippling the water noiselessly, each ripple moving as with fiery life, from the reflection of the fires on the banks. A sound of many voices singing a hymn, in the direction of the negro barges, came floating musically over the water, to the tune of “We're bound for the happy land of Canaan.” All else was still as death, and as I sat upon the deck of the steamer looking at the enchanting scene, I thought of “peace and good — will to men,” rather than of war and war expeditions. We did not leave until near seven o'clock A. M., when all being in readiness at the change of the tide, the whole fleet moved slowly down the river. Nothing occurred of any particular consequence during the voyage.
--N. Y. Tribune.