On getting Hill’s dispatch Wellington pondered much--but came to an unhappy decision. In his reply he wrote, ‘I cannot believe that Soult and the King can venture to move forward to attack you in the position on the Tagus, without having possession of the fortresses in the province of Murcia [Cartagena and Chinchilla] and of Alicante;--unless indeed they propose to give up Valencia entirely. They would in that case[70] bring with them a most overwhelming force, and you would probably have to retire in the direction given to General Alten [i.e. by the Guadarrama Pass, Villa Castin, and Arevalo] and I should then join you on the Adaja. If you retire in that direction, destroy the new bridge at Almaraz.... I write this, as I always do, to provide for every event, not believing that these instructions are at all necessary[71].’ In a supplementary letter, dated two days later, Wellington tells Hill that he imagines that the autumn rains, which have made the siege of Burgos so difficult, will probably have rendered the rivers of the South impassable. ‘I should think that you will have the Tagus in such a state as to feel in no apprehension in regard to the enemy’s operations, be his numbers what they may[72].’ Yet though he does not consider the danger in the South immediate or pressing, he acknowledges that he ought to bring the siege of Burgos to an end, even though it be necessary to raise it, and to give up the hope of its capture. But the continual storms and rains induced him to delay his departure toward the South: ‘I shall do so as soon as the weather holds up a little.’ On the same day (October 12) he wrote to Popham to say that if he had to march towards Madrid, he expected that Souham would follow him, but that Caffarelli must on no account be allowed to accompany Souham. At all costs more trouble must be made in Cantabria and Biscay, to prevent the Army of the North from moving. Popham must not withdraw his squadron, or cease from stimulating the Northern insurgents[73]. Wellington was not aware that Caffarelli was already on the move, and that the diversion in the North--through no fault of the officers in charge of it--had reached its limit of success.