On approaching Centreville the first object that attracted our attention was one of the huge earthworks of the enemy, with large logs placed in the embrasures, the ends pointing toward us, and painted black in imitation of cannon. The earthworks seemed very imperfectly constructed, and from this fact, and the counterfeit guns which surmounted them, it was evident that no fight had been seriously counted on by the absconding forces. The substantial character of their barracks, bake-ovens, stables, and other improvements, confirmed this view; and on reaching Manassas we found the same cheap defenses and the same evidences of security, while the rebel forces were much less than half as great as ours, and within a day's march from us. What was the explanation of all this? Why had we not long before, driven in the rebel pickets, and given battle to the enemy, or at least ascertained the facts as to the weakness of his position? Could the commander be loyal who had opposed all the previous forward movements of our forces, and only made this advance after the enemy had evacuated? These were the questions canvassed by the members of the committee in their passionate impatience for decisive measures, and which they afterward earnestly pressed upon the President as a reason for relieving General McClellan of his command. They were also greatly moved by the fact already referred to, that General McClellan had neglected and repeatedly refused to co-operate with the navy in breaking up the blockade of the Potomac, which could have been done long before according to the testimony of our commanders, while he had disobeyed the positive order of the President respecting the defenses of Washington by reserving only nineteen thousand imperfectly disciplined men for that service, through which the capital had been placed at the mercy of the enemy. Meanwhile the flame of popular discontent had found further fuel in the threats of McClellan to put down slave insurrections "with an iron hand," and his order expelling the Hutchinsons from the Army of the Potomac for singing Whittier's songs of liberty. Of course I am not dealing with the character and capacity of General McClellan as a commander, but simply depicting the feeling which extensively prevailed at this time, and which justified itself by hastily accepting merely apparent facts as conclusive evidence against him.