McClellan had been removed, and Burnside, taking command, led his army to the riverside before Fredericksburg. Carleton was witness of the bombardment of the city by the Federal artillery. From his coign of vantage at General Sumner's headquarters, on the piazza of an elegant mansion, one hundred feet above the Rappahannock, and about three-quarters of a mile from it, he could see, as though it were a great cartoon and he a weaver of the Gobelins tapestry of history, the awful pattern of war. Beyond the sixteen rifled Rodman guns of large calibre and long range, mounted on the river bluff and thrust out through sand-bags, behind the masses of infantry, the pontoon and artillery trains, Carleton stood and saw the making of a bridge in fifteen minutes, in the face of a terrific musketry fire from the opposite shore. Then followed views of the street fight in the doomed city, the shattered houses, the cloudless sky, the setting sun, the gorgeous sunset dyes, the deepening shadows, the masses of men upon the opposite hills, the screaming shells, the puffs of white smoke, the bursting storms of iron, the blood-red flames illuminating the ruin of dwellings, the battle smoke settling in the valley, so densely as to obscure or hide the flashes. All this was before Carleton on that afternoon and evening of that winter's day, December 11th. Then he spread his blanket for a little sleep, expecting to awake to behold one of the greatest battles of modern times; but the sun set without the two great armies coming to close quarters. The next day was a hard one, for Carleton was in the field until night, now watching a bombardment, now a charge, and again a long and stubborn, persistent musketry fire. The shells sang near him, and at one time he was evidently the target for a whole Confederate battery; for, within a few seconds, a round shot struck a few rods in front of him, a second fell to the right, a third went over his head, a fourth skimmed along the surface of the ground, just over the backs of a regiment, lying flat on their faces. As he moved to the shelter of the river bank, a shot dropped obligingly in the water before him. All day long the lines of batteries on the hills smoked like Etna and Vesuvius. Sometimes, between ordnance and musketry, there were twenty thousand flashes a minute. Carleton thus far had seen no battles where the fire equalled that which was poured upon Sumner's command during the last grand, but hopeless, charge at sunset. At nightfall, when the wearied soldiers could lie down for rest, Carleton began the work of writing his letter. Among other things he said: "With the deference to military strategics, my own common sense deprecated attempting the movements which were made, as unnecessary and unwise,--which must be accomplished with fearful slaughter, and which I believed would be unsuccessful.... "It is a plain of Balaklava, where the Light Brigade, renowned in song, made their fearful charge."