The protrusion to the south-westward[3] of the Ist Army towards the Saar, which had not been intended by the supreme Command, had brought its left wing in upon the line of march laid down for the IInd, and detachments of the two armies had to cross each other at Saarbrücken on the 6th. Thus there was indeed no lack of strength at that point; but as a battle on that day was neither expected nor probable, the synchronous arrival of troops had not been pre-arranged, and so detachments could only come up by quite unprescribed routes and arrive one after the other at different hours.
The 14th Division of the VIIth Corps was the first to reach Saarbrücken, towards noon on the 6th.
General Frossard, considering his position there very hazardous, had left the night before, without waiting for permission, and had fallen back with the IInd Corps on Spicheren, where it had entrenched itself. The IIIrd, IVth, and Vth Corps were behind, at distances of from nine to nineteen miles, and the Imperial Guard was about twenty-three miles rearward. The Emperor, therefore, had it in his power to collect five Corps for a battle in the vicinity of Cocheren, or, on the other hand, to support Frossard with at least four Divisions, if that General were confident that his position was strong enough to hold.
The range of heights which upheaves itself immediately behind Saarbrücken is capable of affording a serious obstacle to a hostile passage of the Saar. It was known that the French had evacuated those heights, but General von Kameke thought it prudent to seize them at once, in order to secure the debouche of the columns following him. When, in the forenoon, two squadrons of the 5th Cavalry Division showed themselves on the drill-ground on the ridge above the farther bank, they were greeted with a hot fire from the Spicheren heights. But as it seemed highly probable, from the previous behaviour of the French, that the force seen there was only the rear-guard of the retiring enemy, General von Kameke (commanding 14th Infantry Division) ordered an immediate attack, since he had the promise of reinforcements. General von Zastrow (commanding VIIth Corps), as soon as he recognized that the 14th Division had involved itself in a serious engagement, allowed the 13th to go forward. General von Alvensleben (its commander) also ordered up to Saarbrücken all the available troops of the IIIrd Corps, and with equal promptitude General von Goeben (commanding VIIIth Corps) hurried thither the entire 16th Division. Generals von Döring (commanding 9th Infantry Brigade) and von Barnekow (commanding 16th Infantry Division), belonging respectively to these two Corps (IIIrd and VIIIth), had besides already struck forward from Tudweiler and Fischbach in the direction of the cannon-thunder, even before receiving orders to that effect.