division, and send even single regiments if no more could be spared, to protect the points in the most danger from the enemy. The peril of the army was hourly becoming more imminent. At five o’clock the brigades of French and Meagher, Richardson’s division, third corps, were ordered to the support of General Porter. At six o’clock the enemy again attacked in great force, but failed to break the unwavering line of Union soldiers. At seven o’clock they rushed forward with increased fury, and finally gained the woods held by Porter’s left. A general confusion followed, with more determined assaults from the enemy, forcing Porter’s men from the position they had so nobly held, to a hill in the rear overlooking the bridge. It was now approaching night, and the hearts of the Union troops were heavy with dire apprehension, when the French and Meagher brigades appeared, sternly driving before them the stragglers who were thronging in disorder toward the bridge. They advanced boldly to the front, and by their steady bearing and their brave example so animated the sinking troops that they rallied, reformed behind the welcome reinforcement, and again advanced up the hill prepared to repulse any attack of the enemy. But what had renewed their courage had filled the rebels with dismay; having been many times in the course of the engagement repulsed with severe slaughter, and now hearing the shouts of the fresh troops, the enemy failed to follow up his advantage; and in the gathering gloom of night the rescued regiments made good their retreat, crossed the bridge in safety, and destroyed it behind them. In this battle the rebels captured twenty-two guns, three of which were lost by being run off the bridges in the final withdrawal. It is due to the artillery to say that not until the last successful charge of the rebels were the cannoneers driven from their pieces, or struck down, and their guns captured. The batteries of Diedrich, Ranahan, and Grimm took position in front of General Smith’s line and aided by the First Connecticut artillery, with a battery of siege guns, drove back the rebels in front of General Porter. [Illustration: MAJOR-GENERAL W. T. SHERMAN.] THE CHANGE OF BASE. The weary hours of the sultry night following the battle of Gaines’ Mill were heavy laden to the soldiers of the army of the Potomac.—While the rear guard was taking positions to beat back the advance of the foe on the next day, the main body of the army continued a retreat which every man felt to be ignominious; and rolled backward, like a mighty stream turned from its source, toward the James river. On the evening of June 27th General McClellan assembled his corps commanders at his headquarters, and informed them of the proposed change in his base of operations, his reasons, his choice of route and method of execution.