(f) In the American Civil War a tactical blunder of another kind, due to the impetuosity of the commander of the Independent Cavalry of the Army of Northern Virginia, prevented the Southern commander from obtaining a great strategical advantage over the Army of the Potomac. The latter force had been withdrawn by General McClellan, after the Seven Days' Battle around Richmond, to a secure position at Malvern Hill, where the assaults of the Army of Northern Virginia were beaten back with heavy losses. McClellan continued the withdrawal and had reached Harrison's Landing on the James River. The Independent Cavalry of the Southern Army had previously been dispatched on a false scent, but at 9 a.m. on July 3 touch was regained with the Northern forces, which were sighted from _Evelington Heights_ (July 3, 1862), a commanding ridge within two miles of the bivouacs of the Army of the Potomac, which was resting in apparent security, with inadequate precautions against surprise. General J. E. B. Stuart, the Confederate cavalry commander, {113} reached Evelington Heights with 1,200 sabres and carbines and one light howitzer, and the whole Army of the Potomac, 90,000 all arms, was in bivouacs in full view from the Heights, and it was clear that his presence was not suspected. The nearest column of the force he was covering was six miles away, and there remained about ten hours of daylight. It is easy to see, after the event, that this was a case where "Silence is golden." Stuart should have sent the information to Lee and to every column commander, urging them to press on at all speed, while he occupied the Heights with his dismounted men with the determination to hold his position with fire action, if discovered, until the arrival of one or more columns of the Army of Northern Virginia. But he failed to appreciate the situation, and forgetting the larger question, he seized the opportunity to spread panic in the ranks of the Army of the Potomac, and opened fire with his one light howitzer. The Northerners recovered from the panic caused by this unexpected attack, when it was realised that only one gun was in action against them, and attacked and captured the Heights, and were strongly entrenched there before the nearest Confederate column arrived. (g) Among the examples of Advanced Guard work in Marshal Foch's "Principles of War" is a problem for a battalion as the Advanced Guard of a Brigade. "What is the problem the battalion commander has to solve? It consists in preparing for the brigade to go into action against an enemy who may debouch from Bettwiller. What does the brigade require for such an action? It requires the _space_ necessary for the full employment of its forces, and the _time_ necessary for their arrival and deployment. In order to achieve that double task the battalion commander orders his troops to occupy _the whole space necessary_, and places them in points where they may hold on for the _necessary time_." {114}