The Second Army is to consist of the 9th, 14th, and 15th Army Corps. The course of action prescribed for this is to advance from Trèves through Luxembourg, with the consent of the Grand Duke, following the Trèves-Brussels railway as far as Arlon, whence it is to approach the French frontier between the fortress of Montmedy and Sedan, and in this vicinity, while covering the communications of the main army, draw on itself the attention of the French field army presumably lying behind the northern section of the French frontier fortresses from about Verdun southward, so hindering it from marching westward to swell the forces opposing themselves to the main German army moving by Namur and Charleroi. Having accomplished this ‘holding’ operation, whether with or without a battle, it is to disengage, move westward below Mezieres, and approach that army after it has crossed the frontier. In performing this arduous task the Second Army will have to encounter the physical difficulties of the Eastern Ardennes, and protect its line of communication running perilously near the frontier. To aid in this work, severe at once, and delicate, it is to be furnished with a strong cavalry force, under the command of Lieutenant-General von Kleist. If from behind the curtain of their eastern frontier fortresses the French are bent on taking the offensive, German strategists, says our Correspondent, freely recognise the impossibility, owing to the diversion through Belgium of the bulk of the German force, of hindering them from over-running Alsace and Lorraine up toward the left bank of the Upper Rhine, where the German fortresses would give them halt. Yet such an advance, if attempted, they will not find quite an unchequered promenade. In Lorraine, Metz, for instance, will somewhat interfere with free transport by rail. In the chain of frontier forts the French engineers have designedly left between Toul and Epinal an undefended gap or _trouée_ of considerable breadth. Because of the fortifications of the second line of defence this specious interval is greatly in the nature of a trap, but its debouche toward France nevertheless needs to be watched by a strong field force on either flank.