lue to
positive information. The repetition or confirmation of information
already sent are also of importance, as it is clearly of value to a
commander to know positively that the enemy is still absent, or still
present, at a certain time in a certain locality. In the American
Civil War, during an encounter battle between {108} advanced troops,
the commander of the cavalry of the United States Army held up the
Confederate advanced troops. A sharp fight took place at _Sulphur
Springs_ (October 12, 1863) and the United States cavalry commander
became so absorbed in the battle that he failed to send information to
headquarters, and General Meade did not learn that he was in contact
with the Army of Northern Virginia until late in the afternoon. In the
campaign of _Fredericksburg_, General R. E. Lee, with the Army of
Northern Virginia, was confronted by General Burnside, with the Army of
the Potomac. On November 15, 1862, a patrol of Confederate cavalry
discovered Burnside's troops moving eastwards, and another patrol
brought news the same day that gunboats and transports had entered
Acguia Creek on the Potomac. These two pieces of information,
collected at points 40 miles distant from one another, gave Lee an
insight into his opponent's design. Information gained by aircraft on
September 4 and 5, 1914, and communicated immediately to General
Joffre, led to the discovery of the flank march across the
Franco-British front by the German I. Army, and to the decisive
counter-attack at the _First Battle of the Marne_ (September 6, 1914).

The Advanced Guard commander must be careful how he becomes seriously
engaged, and must avoid any enterprise not strictly in accordance with
the known intentions of the commander of the Main Body. The tendency
to independent action of this kind, which militates against the success
of the best laid plans, was very observable in the early battles of the
Franco-Prussian War of 1870-1871. Actions were hastily entered on by
Advanced Guards, maintained with varying success by the gradual arrival
of reinforcements, and finally concluded with barren results and losses
in excess of those inflicted. At the _Battle of Spicheren_ (August 6,
1870) the Advanced Guard of the 14th Prussian Division commenced the
battle, which had to {109} be sustained for three hours by 11
battalions against 39. During the next three hours 8 more battalions
arrived, and at the conclusion of the battle only 27 batta