Baillie had preceded him, and even before the general had reached Fairfax Court-house, Pegram's battery was hurrying down the Vienna road, with the First and Fourth Regiments of Virginia cavalry just in front. It was the work of a very few moments to form these forces and others that were coming up, into a line of battle, facing the enemy, but by the time they were in position, Stuart himself came up and took command.

"Tell Captain Pegram," he said to a staff-officer, "to advance his battery to the brow of the hill yonder, and open a vigorous fire upon whatever he finds in front. Order Colonel Jones of the First Regiment to take position immediately in rear of the battery, and support it at all hazards."

Within less time than it takes to write the words, Baillie Pegram's guns were hurling shrapnel into the face of the enemy, whose response was menacingly slow and deliberate.

"That looks," said Stuart, presently, to one who rode by his side, "as if they meant business this time. Send orders to the infantry in rear to form a second line, and be ready in case we are beaten back."

It should be explained that during the autumn of 1861 McClellan sent out many expeditions, each wearing the aspect of an advance in force against the Confederate position at Centreville. These movements were in reality intended as threats, and nothing more. The chief purpose of them was to keep the Confederates uneasy, and at the same time to accustom the Federal volunteers to stand fire and to contemplate battle in earnest as the serious business of the soldier.

These advances were made always with a brave show of infantry, cavalry, and artillery, and with all the seeming of the vanguard of an army intending battle. But after a heavy skirmish the columns were always withdrawn, leaving only picket-lines at the front. McClellan was not yet ready to offer battle. It was during that period that President Lincoln, weary of McClellan's delay and inactivity, sarcastically said that if the general had no use for the army, he (Lincoln) would like to borrow it for awhile.

But this day's movement differed in some respects from those that had gone before. It involved a much heavier force, for one thing, and the proportion of artillery to the other arms was greater. Still more significant was the fact that the commander of the expedition, instead of making the customary dash, threw forward a heavy skirmish-line, holding his main body in reserve, and otherwise conducting himself after the fashion of a general sent to hold the front with as little fighting as might be, until a much heavier force could be brought up.

It was Stuart's duty, as the commander of the cavalry, to find out as quickly as possible what lay behind the lines that confronted him, in order that he might know and report precisely what and how much the movement meant. To that end he sent for Colonel Jones, of the First Regiment, and when that most unmilitary-looking of hard fighters presented himself in his faded yellow coat, the pot hat which he always wore at that time, and with his peculiar nasal drawl, Stuart gave the order:

"Take your right company and ride to the right around the flank of the enemy's line. Find out what it amounts to. See if there are baggage and ammunition trains in rear, and if they mean business. The whole thing is probably as hollow as a gourd, but it may be otherwise. Go and find out."

In the meantime, Stuart had dismounted a part of his forces, and ordered them with their carbines to form a skirmish-line on foot in front. The rest of his men—three thousand stalwart young cavaliers, mounted upon horses that had pedigrees behind them—were drawn up in double ranks wherever there was space for a regiment, a company, or a squad of them to stand.