The sun was sinking rapidly westward in the direction of Richmond--that coveted capital of Secessia, for the possession of which so much blood and treasure had been unavailingly expended; the trees, which for so many hours had afforded no shelter from the blinding blaze, except immediately beneath their spreading branches and dust-dimmed leaves, began to cast long shadows eastward; and the fervent heat began to be more sensibly tempered by the breeze creeping in from the placid James. Still the Union troops were resting on their arms, weary but undaunted, awaiting the approach of the Confederates, then (at five o'clock) reported as advancing to the attack. The line was formed as follows: the remnants of Porter's and Sumner's corps on the right; Franklin and Heintzelman in the centre; and Couch's division of Keyes' corps on the left. In position, on the left, were two New York batteries, Robertson's United States battery of six pieces, Allen's Massachusetts and Kern's Pennsylvania batteries. Griffin's United States battery, Weeden's Rhode island, and three from New York, held positions in the centre. On the right were Tidball's, Weed's and Carlisle's regular batteries, a German battery of twenty-four pounders, a battery belonging to the Pennsylvania reserve, and one New York battery--in all about eighty pieces. Within a few minutes of five the signal officers at the various stations waved their telegraphic bunting, announcing the approach of the rebels under Magruder, and immediately afterwards they appeared in sight, in large dense masses reaching apparently quite across the country to the West, North-west and West-south-west,--with cavalry on either flank and artillery thickly scattered at various points, all along their line. Stretching away from the foot of Malvern Hill, in the hostile direction, lay a large open space known as Carter's Field--a field destined that day to be more thickly sown with dead than almost any historic spot on the globe except some portions of the field of Waterloo or that of Grokow. It was a mile long by three quarters of a mile in breadth, enclosed by thick woods on the three distant sides, while that towards the Hill was open. On the two sides flanking the enemy's approach our sharp-shooters were principally concealed. Entirely across Carter's Field stretched the rebel line, while in depth their columns extended so far back that the eye of the signal officer lost them in a wavering line far away in the thick woods extending beyond the scene of the morning's battle.