about ten o'clock
They were , indeed , already in movement against the Confederate position , their attack being directed toward the portion of the line held by Jackson 's division . General Stuart gave orders to Major Pelham , who commanded his horse artillery , and who immediately brought up the guns and began the battle by opening fire on the flank of the enemy . The guns of the Northern batteries at once replied , and for some hours the artillery duel continued , the Federal guns doing heavy execution . For a time attacks were threatened from various points , but about ten o'clock , when the fog lifted , a mass of some 55,000 troops advanced against Jackson . They were suffered to come within eight hundred yards before a gun was fired , and then fourteen guns opened upon them with such effect that they fell back in confusion . At one o'clock another attempt was made , covered by a tremendous fire of artillery . For a time the columns of attack were kept at bay by the fire of the Confederate batteries , but they advanced with great resolution , pushed their way through Jackson 's first line , and forced them to fall back .