This resolution was executed as promptly as it was formed. He instantly raised the siege, and filed his whole army in the night of the 21st under the walls of the castle and over the bridge, which was closely enfiladed by its artillery; a bold and unprecedented manœuvre, which military men adduce as a proof that the march of troops cannot be stopped by the fire of artillery in the night. The allies moved in silence and good order; but a party of Guerrillas, regardless of discipline, then, as at all times, put their horses to their speed, and the clatter which they made alarmed the garrison. A fire was consequently opened from the guns which were directed on the bridge, and the first discharge was most destructive; but the gunners then lost the range and direction, and their farther fire served only to quicken the speed of the carriages. Every thing was brought away in this retreat except the three disabled guns, and the eight pieces of the enemy which had been taken in the horn-work. The loss of the allies during the siege amounted to 24 officers and 485 men killed; 68 officers and 1487 men wounded ♦RETREAT FROM BURGOS.♦ and missing. The enemy did not begin to follow till late on the ensuing day; 10,000 of their troops encamped that day on the south of Burgos, and on the morrow at noon they came up in force with the retreating army. Sir Stapleton Cotton detained them for above three hours at the passage of the Hormaza, in front of Celada del Camino; they were twice charged there by Major-General Anson’s brigade with great success, and the rear-guard continued to fall back in the best order, till the Guerrillas on their left were driven in and came flying upon them, four or five of the enemy’s squadrons being mixed with them in pursuit. In the confusion which ensued, the French were mistaken for Spaniards, and, favoured by that mistake, they fell upon the flank and rear of the allies. Some loss was sustained, and Lieutenant-Colonel Pell, of the 16th dragoons, was taken prisoner, having had his horse shot. A very superior body of cavalry, in which the enemy were strong, now came up, and the allied cavalry fell back hastily, lest they should be surrounded; but having crossed a wide and deep ditch by a narrow bridge, the brigades of Major-Generals Bock and Anson charged their pursuers when only part had filed over: in this they were repulsed, hardly pressed, and forced upon the infantry rear-guard of German light troops under Colonel Halkett; that officer formed his troops in four squares, and the men behaving, as that legion ever did, admirably, repulsed the enemy in several charges, and checked the ♦THE ALLIES CROSS THE PISUERGA.♦ pursuit. The right of the army crossed the Pisuerga that afternoon at Torquemada, and the left at Cordovilla, where head-quarters were established that night.