By June 10, Sherman was ready to resume the advance. The Southerners had taken up a line north of Marietta that ran from Brush Mountain on the east to Pine Mountain in the center to Lost Mountain on the west. McPherson moved against the right flank of this line, Thomas against the center, and Schofield against the left. Rain fell almost every day and hampered the Northern advance. For several days there was heavy skirmishing in which the Federals captured Pine Mountain and made gains at other points. Bishop-General Polk was killed on Pine Mountain by a Union artillery shell on June 14, when he foolishly exposed himself to enemy fire. Maj. Gen. William W. Loring commanded Polk’s Corps for several weeks until a permanent replacement, Lt. Gen. Alexander P. Stewart, took command. By the 16th, Schofield’s advance had been so successful that the Southerners were forced to give up Lost Mountain. For several days, Johnston tried to hold a new line that ran west from Brush Mountain and then turned southward. This line was enfiladed by the Federal artillery, however, and during the night of June 18-19 the Confederates abandoned it and took up a new position extending along the crest of Kennesaw Mountain and off to the south. Hardee’s Corps held the left of this line, Loring’s was in the center, and Hood’s was on the right. When Sherman encountered this strong position, he extended his lines to the south to try to outflank Johnston. He moved most of McPherson’s army to the area directly in front of Kennesaw Mountain and placed Thomas’ army in line on McPherson’s right with orders to extend to the right. In the days that followed, McPherson and Thomas were engaged in what amounted to a siege of the Southern position. Little progress could be made on the ground but the artillery on both sides was used in attempts to batter and weaken the enemy. Day after day, the big Union guns pounded the Southern line, their fire being answered by Confederate cannon high on Kennesaw Mountain. Meanwhile, Sherman drew Schofield’s army in from the Lost Mountain area and ordered it to move south on the Sandtown Road, which ran west of the Federal position toward the Chattahoochee. After a long and muddy march, Schofield’s men reached Nose’s Creek at dark on June 19. On the following day, they crossed the swollen stream and drove the Southerners away. The bridge was rebuilt; on the 21st their advance was resumed. That same day, the right of Thomas’ army established contact with Schofield near Powder Springs Road. Johnston had seen the Federal right being extended and was aware of the dangers it presented to his line of communications. To meet this threat the Confederate commander shifted Hood’s Corps from the right of his line to the left during the night of June 21-22. By early afternoon of the 22d, Hood’s men were in position on Hardee’s left.