Our plan of concentration had foreseen the possibility of two principal actions, one on the right between the Vosges and the Moselle, the other on the left to the north of Verdun-Toul line, this double possibility involving the eventual variation of our transport. On August 2, owing to the Germans passing through Belgium, our concentration was substantially modified by General Joffre in order that our principal effort might be directed to the north.
From the first week in August it was apparent that the length of time required for the British Army to begin to move would delay our action in connection with it. This delay is one of the reasons which explain our failures at the end of August.
Mulhouse occupied.
Awaiting the moment when the operations in the north could begin, and to prepare for it by retaining in Alsace the greatest possible number of German forces, the General in Chief ordered our troops to occupy Mulhouse, (Mülhousen,) to cut the bridges of the Rhine at Huningue and below, and then to flank the attack of our troops, operating in Lorraine.
This operation was badly carried out by a leader who was at once relieved of his command. Our troops, after having carried Mulhouse, lost it and were thrown back on Belfort. The work had, therefore, to be recommenced afresh, and this was done from August 14 under a new command.
Enemy losses.
Mulhouse was taken on the 19th, after a brilliant fight at Dornach. Twenty-four guns were captured from the enemy. On the 20th we held the approaches to Colmar, both by the plain and by the Vosges. The enemy had undergone enormous losses and abandoned great stores of shells and forage, but from this moment what was happening in Lorraine and on our left prevented us from carrying our successes further, for our troops in Alsace were needed elsewhere.
On August 28 the Alsace army was broken up, only a small part remaining to hold the region of Thann and the Vosges.
The purpose of the operations in Alsace was, namely, to retain a large part of the enemy's forces far from the northern theatre of operations. It was for our offensive in Lorraine to pursue still more directly by holding before it the German army corps operating to the south of Metz.
This offensive began brilliantly on August 14. On the 19th we had reached the region of Saarburg and that of the Etangs, (lakes,) and we held Dieuze, Morhange, Delme, and Château Salins.