The Emperor, apparently believing that Bagration was stronger than was actually the case, and that he might break northward, directed Eugène with the 4th Corps on July 7th in the track of Davout; but soon becoming aware that his intelligence was false, recalled him to Smorgoni, where he arrived on the 12th. On the 14th Eugène left to support the advance on Drissa, marching by way of Vileika, where the magazines captured by Colbert afforded supplies. Nevertheless food was invariably scanty. The wretched roads wore out the men, who fell sick or straggled in numbers. The horses fared still worse, and many died. St. Cyr, meanwhile, had marched by Novi Troki to Vilna, whence he was directed by Glubokoïe also on Drissa. The march of the unhappy Bavarians will later be alluded to. On July 11th Napoleon ordered Mortier with part of the Guard also upon Glubokoïe, and next day the first detachment of the Head-quarters Staff was directed thither. De Fezensac, who was with this detachment, notes that the Young Guard were already suffering from the effects of the tropical heat, scanty rations and fatigue--especially the newly formed “Flanqueurs-Chasseurs.” Yet Napoleon in a letter of the 11th suggests that Mortier can live on the country! The 10th Corps, after clearing the right bank of the Niemen, had been directed north-eastward towards Mitau and Riga, which latter place it was destined to besiege. The operations of the 10th Corps were so isolated and otherwise of so languid a nature that they may for the moment be ignored. Here it is only necessary to observe that the 10th Corps was moving north-eastward on a broad front, the Prussians advancing on Mitau, the 10th Division, Poles and Germans under Grandjean, on Dünaburg. At the latter place there was a bridge-head garrisoned by some reserve battalions. Davout, having occupied Minsk, remained there for some days. The halt was necessary in order to rally the stragglers and re-establish discipline. It was also utilised in commencing the organisation of Minsk as one of the main depôts of the army, for which its situation at the intersection of the Warsaw-Moscow and Vilna-Kiev high-roads admirably fitted it. Davout had rightly inferred that his occupation of Minsk would oblige Bagration to retire upon Bobruisk. He might then endeavour to march up the left bank of the Berezina to the Minsk-Smolensk road at Borisov or Bobr, and thence press on to join Barclay. The Marshal accordingly sent forward his advance-guard, under Bordesoulle, to reconnoitre Borisov and occupy it if possible. He estimated Bagration’s strength, from the reports of spies and peasants, at 16 to 18 regiments of infantry and 120 guns, besides cavalry. The evaluation was much below the truth, and gives the impression that his informants had only seen and counted the regiments of one of Bagration’s two corps and the 27th Division.