Siege of Belfort.—In the south-eastern theatre of war, the forces detailed to operate against Belfort had been only gradually brought together under cover of the XIVth Army Corps.
The town is surrounded by a bastioned enceinte. The citadel has a wide command, built as it is on lofty rocks, which, to increase the development of fire, are encircled by successive tiers of works in terrace-formation. On the left bank of the Savoureuse, newly constructed lines of defence protected the suburb and railway station. On the high adjacent ridge to the north-east the forts of La Miotte and La Justice, with the enclosing lines connecting them with the main fortress, formed a spacious intrenched camp. Hostile occupation of the lofty eminences of the two Perches (Hautes and Basses) would certainly endanger the whole defensive position, dominating as they did even the citadel from the south at a distance of only 1100 yards, and whence the works on the left bank of the river could be brought under fire. But two forts of masonry had been constructed on the Perches before the advent of the enemy, and further to strengthen the defence the nearest copses and villages, as for instance Pérouse and Danjoutin, had been intrenched.
The fortress was by no means deficient in bomb-proof accommodation. Its armament consisted of 341 heavy guns, and it was provisioned for five months.
When immediately after the opening of the campaign, the VIIth French Corps vacated Alsace, only about 5000 Gardes-Mobiles remained in Belfort, but its garrison, increased by calling in National Guards, now exceeded 17,000.
The vigilant Commandant, Colonel Denfert, laid great stress on the maintenance in force of the environs in his front. The advanced posts were every day assigned to fresh operations, which the artillery of the fortress had to cover at extreme ranges.
On the opposite side, General von Tresckow (commanding 1st Reserve Division) had available at the outset, a force of not more than twenty weak battalions of Landwehr, five squadrons and six field-batteries, in all barely 15,000 men. He had at first to confine himself to a mere investment. The troops, intrenched in the villages round a wide circumference, had to repel many sorties.
Orders were received from the supreme Headquarter to set about the regular siege of the place. General von Mertens was charged with the direction of the engineer operations, and Lieut.-Col. Scheliha with that of the artillery attack. The difficulties of the undertaking were obvious. The rocky nature of the soil could not but increase the labour of throwing up earthworks, and the cold season was approaching. The attack could be carried on successfully only from the south against the main work—the formidable citadel. Only fifty heavy guns were available for the time, and the infantry strength was not sufficient to efficiently invest the place on all sides.
In these circumstances, there devolved on General von Tresckow the task of attempting the reduction of Belfort by a mere bombardment. Towards this purpose the attack was chiefly directed from the west, in which quarter, after the enemy's garrison had been driven out of Valdoye, the infantry occupied Essert and Bavilliers, as well as the adjacent wooded heights. On December 2nd seven batteries were constructed on the plateau between these two villages by 3000 men, under cover of two battalions. The hard-frozen ground added to the difficulties of the work; yet, notwithstanding the moonlight night, the operations would appear to have escaped the attention of the besieged. When on the following morning the sun had dispersed the fog and made visible the objects, fire was opened.
The fortress replied at first but feebly, but afterwards with increasing vigour from the entire line of works, even from Forts La Miotte and La Justice at a range of 4700 yards, and the losses in the trenches were considerable.
Four more batteries in front of Bavilliers were armed, and on the fall of La Tuilerie the infantry pressed on to within 170 yards of the enemy's most advanced trenches. The artillery fire caused a conflagration in the town; but the ammunition was soon exhausted, whilst the lofty citadel maintained unchecked an effective fire, and repeated sorties on the part of the garrison had to be repelled. It was now clear, since no decisive result had followed the methods hitherto resorted to, that only by a regular attack could that be attained.