The fight began about ten o'clock. Both sides were soon re-enforced. After two hours' stubborn fighting the Confederates were driven back across the pike, beyond Young's Branch of Bull Run, and took up a second position on a hill each side of the Henry House. The whole Union force had now crossed Bull Run. Griffin's and Ricketts' powerful batteries were posted in favorable positions, whence they poured a deadly fire upon the Confederates. The whole Union line advanced to the turnpike. About two o'clock the Confederates were forced to abandon their second position and fall back still farther. Early in the morning Beauregard and Johnston had given orders for an attack upon the Union forces across the river, not knowing that McDowell had assumed the offensive. These orders were now countermanded, and all available troops hurried up the Sudley road toward the Warrenton pike front. Till after noon the prospect for the Confederates looked gloomy. They had been steadily driven back. Some of their regiments had lost heavily, while all were more or less demoralized. Johnston and Beauregard gave their personal direction to re-forming the line upon a second ridge to the south of the Warrenton pike, under cover of a semicircular piece of woods. Twelve regiments, with twenty-two guns and two companies of cavalry, concentrated in this favorable position and awaited the Union advance. [Illustration: Map.] Bull Run-Battle of the Forenoon. McDowell had fourteen regiments available for the attack. He decided to hurl them against the Confederate centre and left. About half-past two Griffin's and Ricketts' batteries took up an advanced position on Henry Hill. The Confederate guns opened fire, and a short artillery duel took place. A Confederate regiment now advances to capture the exposed batteries. They are mistaken for Union re-enforcements and allowed to come within close range. The muskets are levelled. A terrible volley is poured into the batteries. The gunners are stricken down. The frantic horses dash madly down the hill. After a little confusion the Union troops boldly advance and retake the batteries. The battle surges back and forth. The guns are three times captured and lost again. The fight becomes general along the Confederate centre and left. The Union generals are getting alarmed. So far they have been confident of victory. Now regiment after regiment is going to pieces in this terrific melee, and still the "rebels" hold their ground. About half-past four o'clock General Early arrives by rail with three thousand more of Johnston's army, and, assisted by a battery and five companies of cavalry, bursts upon the extreme right flank and rear of McDowell's line. [Illustration: Map.] Bull Run--Battle of the Afternoon.