Burgos, instead of Vittoria, was now become the pivot of operations, and the right of his army being secured, the emperor prepared to change his front, and bear down against the armies of Castaños and Palafox, with a similar impetuosity; but it was first necessary to ascertain the exact situation of the British force. Napoleon believed that it was concentrated at Valladolid, and he detached three divisions of cavalry and twenty-four pieces of artillery, by Lerma and Palencia, with orders to cross the Douero, to turn the flank of the English, threaten their communications with Portugal, and thus force them to retire. It was soon discovered that the heads of their columns had not penetrated beyond Salamanca and Astorga, and that many days must elapse before they could be concentrated, and in a condition to act offensively. Certain of this fact, the emperor let loose his three divisions of cavalry, and eight thousand horsemen sweeping over the plains, vexed all Leon and Castille. The authorities showed no firmness; the captain-general, Pignatelli, fled in consternation; the people submissive and fearful, displayed no enthusiasm, and disconcerted by the rapid movements of the French, spread a thousand confused and contradictory reports. The incursions of the cavalry extended to the neighbourhood of Astorga, to Benevente, Zamora, Toro, Tordesillas, and even to the vicinity of Salamanca. Such was the fear, or the apathy of the inhabitants, that thirty dragoons were sufficient to raise contributions at the gates of the largest towns; and after the overthrow of Espinosa was known, ten troopers could safely traverse the country in any direction. The front of the French army being now changed, the second corps, hitherto the leading column of attack, became a corps of observation, covering the right flank, and protecting the important point of Burgos, where large magazines were establishing, and upon which the reinforcements continually arriving from France were directed. The exact situation of the other corps was as follows: The first corps, the guards, and a part of the reserve, were at Burgos; and Ney, with the sixth, occupied Aranda de Douero; the march of his force from the Ebro had been made with a view to intercept the army of Estremadura on the side of Madrid; but the sudden destruction of that body of troops having rendered this precaution useless, Ney was equally well placed to cut the communication of Castaños with the capital. General Lagrange occupied Logroña, and Moncey, with three divisions of infantry and his light cavalry, was at Lodosa. The Spanish army of the centre was consequently turned and cut off from Madrid even before Castaños was aware that the campaign had commenced. [Sidenote: Baron Larrey’s Surgical Campaigns.]