To cover this retreat, the Army Reserve was to hold Pontarlier till all the baggage-trains should have passed La Cluse, while the XVIIIth Corps was to take up a covering position between the two forts. Defensive works there were at once set about. What of the XVth Corps on the way by Morez had failed in getting through with the cavalry was to try to cross into Switzerland at any available point. _February 1st._--When the advanced guard of the IInd Corps now advanced on Pontarlier from Ste. Colombe, it met with but slight resistance at the railway station. The Colberg Grenadiers took possession of the town without a struggle, and captured many prisoners, but then found the road on the further side entirely blocked by guns and waggons. They could pass beyond on either side of the road only with difficulty through deep snow. Just in front of La Cluse the road winds between high rocky precipices into the wide basin of the Doubs, completely commanded by the isolated fortalice of Joux perched on the solid rock. On debouching into the open the foremost companies were received by a hot fire. Four guns, dragged up thither with the greatest exertions, could make no head against the heavy guns of the fort, and the French themselves here passed to the attack. The Colberg Fusiliers had meanwhile climbed the heights to the left, followed by the 2nd Battalion of the Regiment and a battalion of the 49th Regiment, which drove the French out of the farmsteads on the rifted upland. The steep cliff on the right was also scaled, several rifle sub-divisions of the 49th climbed the acclivity up to La Cluse, and the Colberg Grenadiers advanced to the foot of Fort Neuv. To take the strong fortalices by storm was obviously impossible, and furthermore because of the nature of the ground the fugitive enemy could scarcely be overtaken in force. Of the French, 23 officers and 1600 men were taken prisoners, with 400 loaded waggons; of the Germans, 19 officers and 365 men had fallen, mostly of the Colberg Regiment. The troops spent the night on the field of the fighting. As no large force could come into action at La Cluse, General von Fransecky had ordered the main body of the Corps to march further southward to Ste. Marie. To avoid the necessity of crossing the steep chain of the Jura, General von Hartmann first betook himself to Pontarlier to avail himself of the better roads from thence, but his progress was stopped, the fight at La Cluse having assumed unexpected proportions. The VIIth Corps and the 4th Reserve Division, which had reached the Doubs at noon, were equally unable to get at the enemy.