In the meantime Napoleon, on learning that the German troops had entered France from the south through Basle, had sent pressing orders into the Bourbonnais, Auvergne, and Burgundy, to make a levy of conscripts as soon as possible and send them to Paris. At the same time the depôts of Dauphiny and Provence, as also the conscripts in the eastern departments, were to assemble at Lyons to close to the enemy the approaches from Switzerland and Savoy, and if necessary to operate on his rear. The prefects of Burgundy, Picardy, and Normandy, and of Touraine and Brittany, were to appeal to the communes to form companies of National Guards _d'élite_, who were to march to Paris, Meaux, Montereau, and Troyes. These arrangements were hardly made in time to present a serious obstacle to the invaders. The civil authorities and the regular troops began to make a hasty retreat before the armies of the coalition, and were leaving the inhabitants to themselves without arms or guidance. It thus happened that some bodies of troops coming from the south found themselves in an isolated position, and uncertain whether they ought to continue their route or fall back. Such a case happened on the Saône; three battalions of infantry, certain artillerymen called to Vincennes to assemble at the great central depôt which the Emperor was organising there, and some detachments of various arms making their way for Dijon, to push on thence towards Troyes--found themselves on the flank of the left column of the army of Bohemia. They retraced their steps, and made a rather long détour, hoping to get beyond the enemy's right, and resume the route for Troyes through Beaune, Sémur, Montbard, and Châtillon-sur-Seine; but surprised by bad weather and snow, during a night march in the mountains of the Côte-d'Or, they lost their way, and found themselves in the morning at Saint-Seine, which was already occupied by a body of Austrian pioneers. The French were much limited in point of munitions, and had no artillery. They could not force the passage, and were obliged to fall back into the valley of Suzon, hoping still to find the road from Dijon to Langres clear. But at Thil-le-Châtel they came upon another body of the enemy, and had to retire towards the small town of La Roche-Pont, for it was evident that they were cut off. The colonel who commanded this small column was instructed, should it be impossible to reach Langres, to take up a position at Auxonne or at La Roche-Pont, to keep his ground there, and to form a nucleus of defence until the arrival of Augereau's force, which was to march from Lyons through Macon, Châlon, and Gray, to fall on the rear of Prince Schwartzenberg.