In Paris all preparations were actually made for a great sortie. But as the earlier attacks on the front of the VIth Corps had shown that this section of the investment was materially strengthened by fortifications about Thiais and Chevilly, it was decided in the first instance to gain the plateau east of Joinville and from thence to bend rightward towards the south. The attention of the Germans was to be distracted by attacks in the opposite direction.
On the 18th,[45] the day on which the Army of Orleans had vainly striven to press forward to Beaune la Rolande, General Ducrot assembled the IInd Army of Paris in the neighbourhood of Vincennes, and Mont Avron was occupied on the following day by Hugues' Division of the IIIrd Army. As, however, the construction of the bridges (over the Marne) at Champigny and Bry was delayed, the battle was postponed till the 30th; but it was left to the commanders of the subordinate affairs to carry them out simultaneously with the chief enterprise or in advance of it. Accordingly, Maud'huy's Division assembled in the night of 28th--29th behind the redoubt of Hautes Bruyères, and advanced against L'Hay before daybreak.
Warned by the heavy firing from the southern forts, General von Tümpling (commanding VIth Corps) had early ordered the 12th Division to get under arms in its fighting positions, and the 11th to assemble at Fresnes.
The French, favoured by the darkness, made their way through the vineyards into L'Hay; but were successfully driven back by the Germans with the bayonet and clubbed arms.
After a prolonged fire-fight, the French renewed their onslaught at 8.30, but without success; and then the defenders, reinforced from the reserve, retaliated with a vigorous counterstroke. At ten o'clock the enemy retreated to Villejuif.
Admiral Pothuau at the same time had moved up the Seine with Marines and National Guards. An outpost at Gare aux Boeufs was surprised and captured, and Choisy le Roi was fired upon by field-guns, fortress artillery, and gunboats which appeared on the Seine. Just as the Grenadiers of the 10th (Prussian) Regiment were on the point of making an attack, General Vinoy broke off the fight.
This demonstration cost the French 1000 men and 300 uninjured prisoners; the Prussians, remaining under cover, lost only 140 men. The fortress kept up its fire till mid-day, and then the enemy was allowed a short truce, to remove his numerous wounded.