On the 21st came the final orders for retreat. The artillery were directed to burn all that could not be carried off--platforms, fascines, &c.--to blow up the works on San Miguel, and to retire down the high-road to Valladolid. The three 18-pounders were taken a few miles only. The roads being bad from heavy rain, and the bullocks weak, it was held that there was no profit in dragging about the two guns which had lost trunnions and were practically useless. The surviving intact gun shared the fate of its two ‘lame’ fellows: all three were wrecked[59], their carriages were destroyed, and they were thrown out on the side of the road. The artillery reserve, now reduced to the five ineffective 24-lb. howitzers, then continued its retreat. [Illustration: BURGOS] On the night of the 21st-22nd, Pack’s brigade and the other troops left to hold the works retired, the covering army being now in full retreat by various roads passing through or around the city. The main column crossed at the town bridge--the artillery with wheels muffled with straw to deaden their rumbling--risking the danger of being shelled in the darkness by the Castle, which had several guns that bore upon it. The long series of mishaps which constituted the history of the siege of Burgos ended by the failure of the plan for the explosions on San Miguel: the French found there next day more than twenty barrels of powder intact. The arsenal in the town was fired when the last troops had passed, but was only partly consumed. Next morning (October 22) the advanced guard of the Army of Portugal entered Burgos, and relieved the garrison after thirty-five days of siege. Dubreton had still nearly 1,200 effective men under arms: he had lost in his admirable and obstinate defence 16 officers and 607 men, of whom 304 were killed or died of their wounds. The corresponding total British casualty list was no less than 24 officers and 485 men killed, 68 officers and 1,487 men wounded and missing [the last item accounting for 2 officers and 42 men]. Almost the whole of the loss came from the ranks of the 1st Division and Pack’s Portuguese, the 6th Division troops having had little to do with the trenches or assaults[60]. The external causes of the raising of the siege will be dealt with in their proper place--the strategical narrative of the general condition of affairs in both the Castiles which opens the next chapter. Here it remains only to recapitulate the various reasons which made the siege itself a failure. They have been summed up by several writers of weight and experience--John Jones, the official historian of the sieges of Spain, John Burgoyne the commanding engineer, William Napier, and Belmas the French author, who (using Jones as a primary authority) told its story from the side of the besieged. Comparing all their views with the detailed chronicle of the operations of those thirty-five eventful days, the following results seem to emerge.