Few places present a more formidable appearance; the only land approach is over a low sandy isthmus, occupied by one front of fortification, and this narrow road is commanded by the castle; but on the left flank there are considerable sand-hills some 600 or 700 yards distant, which completely enfilade and take in reverse the front defences. Those which cross the isthmus are a double line of works, with the usual counterscarp, covered way, and glacis; but those which run lengthways consist only of a single line, and trusting to the waters in their front to render them inaccessible, are built without any cover. The northern line is from top to bottom quite exposed to the sand-hills; the Urumea, which washes the town on that side, is fordable for some hours before and after low water, and the tide recedes so much that during that time there is a considerable space left dry by which troops can march to the foot of the wall. Yet the wall had been left uncovered, though Marshal Berwick had availed himself of this defect when he attacked the place in 1719, and by effecting a breach there had made the garrison retire into the castle. In the revolutionary war, St. Sebastian’s was taken by the French without resistance; for though the troops would have done their duty in defending it, the inhabitants, rather than endure the horrors of a siege, allowed the magistrates, some of whom were timid and others traitorous, to surrender. ♦DISTRIBUTION OF THE ALLIED ARMY.♦ After the battle of Vittoria, Jourdan had thrown a garrison of between 3000 and 4000 men into the place. The conduct of the siege was intrusted to Sir Thomas Graham, and the fifth division, under Major-General Oswald, consisting of Major-Generals Hay and Robinson’s British brigades, and Major-General Spry’s Portugueze, were employed in carrying it on. The first division, under Major-General Howard, consisting of the 1st and 2nd brigades of guards under Colonel Maitland and Major-General Stopford, with the brigades of the German legion, and Lord Aylmer’s, were in position covering the great road between Irun and Oyarzun, and supporting Don Manuel Freyre’s Spanish corps which crowned the heights of S. Marzial and guarded the line of the Bidassoa from the Crown Mountain to the sea. Giron and Longa kept up the communication with the left of the centre at Vera: this consisted of the 7th and light divisions, under the Earl of Dalhousie and Baron Alten ... the former posted in the pass of Etchalar, the latter on the mountain of S. Barbara, and in the town of Vera. The right of the centre, commanded by Sir Rowland, occupied the valley of Bastan, and with Major-Generals Pringle and Walker’s brigades of the 2d division, under Lieutenant-General the Hon. Sir William Stewart, guarded the passes of Maya. The Conde de Amarante, with Colonel Ashworth and Brigadier-General Da Costa’s Portugueze brigades, held the minor passes of Col d’Ariette and Col d’Espegas on the right, leading also into