effect upon the troops; and if Sedgwick had been ordered to storm the Fredericksburg lines, the whole Federal force could have been employed, and the Confederates, assailed in front and rear simultaneously, must, to say the least, have been embarrassed.  But in abandoning his design of crushing Lee between his two wings, and in retiring to the stronghold he had prepared, Hooker did what most ordinary generals would have done, especially one who had served on the losing side at Fredericksburg.  He had there learned the value of intrenchments.  He had seen division after division shatter itself in vain against a stone wall and a few gun-pits, and it is little wonder that he had imbibed a profound respect for defensive tactics.  He omitted, however, to take into consideration two simple facts.  First, that few districts contain two such positions as those of the Confederates at Fredericksburg; and, secondly, that the strength of a position is measured not by the impregnability of the front, but by the security of the flanks.  The Fredericksburg lines, resting on the Rappahannock and the Massaponax, had apparently safe flanks, and yet he himself had completely turned them, rendering the whole series of works useless without firing a shot.  Were Lee and Jackson the men to knock their heads, like Burnside, against stout breastworks strongly manned?  Would they not rather make a wide sweep, exactly as he himself had done, and force him to come out of his works?  Hooker, however, may have said that if they marched across his front, he would attack them en route, as did Napoleon at Austerlitz and Wellington at Salamanca, and cut their army in two.  But here he came face to face with the fatal defect of the lines he had selected, and also of the disposition he had made of his cavalry.  The country near Chancellorsville was very unlike the rolling plains of Austerlitz or the bare downs of Salamanca.  From no part of the Federal position did the view extend for more than a few hundred yards.  Wherever the eye turned rose the dark and impenetrable screen of close-growing trees, interlaced with wild vines and matted undergrowth, and seamed with rough roads, perfectly passable for troops, with which his enemies were far better acquainted than himself.  Had Stoneman’s cavalry been present, the squadrons, posted far out upon the flanks, and watching every track, might have given ample warning of any turning movement, exactly as Stuart’s cavalry had given Lee warning of Hooker’s own movement upon Chancellorsville.  As it was, Pleasonton’s brigade was too weak to make head against Stuart’s regiments; and Hooker could expect no early information of his enemy’s movements.