It need not be said that the supporting troops on the south front could nowhere be safe from the fire of the heavy fortress guns, nor the foreposts from that of the Chassepôts. The latter consequently often could not be relieved for several days, and the relief was usually effected at night. The less the success of the French arms in the open field, the more lavish were they in the expenditure of ammunition from their works. Mont Valérien hurled its giant shells to a distance of from four to five miles, but this incessant cannonade, to the din of which the ear was soon accustomed, did little damage.
The Artillery Attack on the Southern Front.—Till Mont Avron was taken, the Germans had only been able to oppose field guns to French fortress artillery. But early in January their preparations were at last so far forward that seventeen batteries, long since completed, could be armed with heavy guns against the south front of Paris. A battery stood apart on the left flank in the park of St. Cloud to the north of Sèvres; four were close together on the steep slope of the height west of the Château Meudon; five on the edge of the plateau of Moulin de la Tour, where the mill, serving to guide the aim of the enemy, had been blown up. Four more batteries occupied a lower position between Fontenay and Bagneux. Two, between Chevilly and La Rue, served as protection against a flank movement from Villejuif, with the field artillery of the IInd Bavarian and VIth Corps. Dressing-stations were prepared, and intermediate depôts were supplied with reserve ammunition from the great magazines at Villacoublay.
Under Generals von Kameke[78] and Prince Hohenlohe[79] Colonels von Rieff and von Ramm conducted the artillery attack, General Schulz commanded the engineer attack. The men served twenty-four hours in the batteries, and then had two days' rest. The officers had but one day's rest.
The heavy guns were brought up on January 3rd, by day, into the batteries which lay covered, without any interference; into all the others during the night, after the enemy's outposts had been driven in. Thus on the morning of the 4th 98 guns were ready to open fire: of these 28 were directed on Issy, 28 on Vanves, and 18 on Montrouge, 10 against the emplacements between the first two forts. But a thick fog hid every object, and it was not till January 5th at 8.30 in the morning, that the signal shot was given for opening fire.
January 5th.—The enemy promptly replied. There were in Fort Valérien 106 guns, in Issy 90, in Vanves 84, and in Montrouge 52; there were about 70 in the sectors of the enceinte concerned and at Villejuif, 16-cm. guns for the most part; so the attack at first was heavily taxed. But when at about noon all its batteries came into action, the situation gradually improved and the greater accuracy of the German fire told. Fort Issy had almost entirely ceased firing by two o'clock, nine guns were dismounted in Vanves, and its garrison had lost thirty men; only Montrouge still replied with vigour. The fire was now taken up by the guns of the enceinte, but the forts never again gained the upper hand of the attack. Some gunboats appearing about Point du Jour very soon had to retire. The field artillery of the IInd Bavarian and VIth Corps also co-operated so energetically that no attack was attempted from the works at Villejuif, nor was a single shot fired on the batteries at Bagneux. A number of wall-pieces and long-range Chassepôts taken from the enemy did such good service that the French abandoned more and more of their rayon. The German outposts took possession of the trenches of Clamart, and in the course of the night reversed them against the defence.
Only a couple of 15-cm. shells were thrown into the city itself as a serious warning; the first thing to be done was to batter down the outworks, and for some few days the firing was exclusively directed on these. A stubborn return fire came from Montrouge and from a mortar-battery in a very advantageous position behind the high railway embankment to the east of Issy; and especially from the south front of the enceinte, nearly four and a half miles long in a straight line. Foggy weather on some days necessitated the suspension or entire cessation of firing. But meanwhile the foreposts had advanced to within 815 and 490 yards of Forts Issy and Vanves respectively. New batteries were constructed further forward, and armed with thirty-six guns from those evacuated in rear.
January 10th.—The French garrison meanwhile was again displaying great activity. On January 10th it succeeded in the dark hours in surprising the weakly-held post of Clamart. Three battalions were now posted in the place, and a shelter-trench some 1300 yards long was dug connecting Clamart with Châtillon.[80]
January 13th.—The IInd Army of Paris was still outside the city on the east and north fronts from Nogent to Aubervillers. After some small alarms, on the evening of the 13th strong bodies advanced from Courneuve and Drancy against Le Bourget under cover of a heavy fire from the forts. But the troops in occupation there were on the alert, and being soon reinforced by several companies, repulsed the attempts of the French to storm it, repeated as they were until two o'clock in the morning.
January 14th.—On this day the French made a renewed sortie on Clamart with 500 marine infantry and several battalions of National Guards. These last assembled at the adjacent railway-station with a great deal of noise, and their approach was reported about midnight. The fight lasted a full hour, and ended with the retreat, or rather flight, of the assailants. Patrols followed them close up to the trenches of Issy.