The evening was calm and sultry--but the extreme verge of the horizon became heavily overcast, and persons conversant with “skyey influences” might have easily foretold a coming storm. It was now dusk--big drops began to fall, some of the brigades had already reached the ground marked out for their night positions, the guns were parked, and the horses of the cavalry picketed. Others were, however, only moving to their bivouacs; and Pakenham’s, the third division, being separated from the remainder of the army by the Tormes, had guarded against sudden attack by intrenching the commanding height it rested on. Suddenly a torrent fell--the wind rose and swept across the open hills with amazing violence--the thunder-clouds burst--and, by the glare of lightning, the sparkling arms of infantry masses were visible over the whole extent of the position, as the last brigades pressed through the tempest to occupy their ground. No shelter the allied army could obtain could have averted a summer shower--and all in a few minutes were drenched to the skin; while the cavalry horses, scared by the lightning, broke from their picketings, and trampling upon their riders rushed madly to and fro, occasioning indescribable confusion. Many of the animals were recovered by the exertions of the dragoons, but numbers of the men were injured in the attempt, and thirty horses, having got within Marmont’s lines, were secured by the French. The allied position had its right upon one of two hills called the Arapiles; its left below the ford of Santa Martha; while its cavalry held Calvarasa de Abaxo. Marmont occupied Calvarasa de Arriba and a contiguous hill, called Neustra Senora de la Pena. Nothing could be more imposing than the parallel movements of the rival armies during the last three days. Far as the eye could range, masses, apparently interminable, pursued their march with beautiful regularity--now displayed in brilliant sunshine as they swept over a contiguous height--now lost where an accidental dipping of the ground for a time concealed the column. Generally both armies abstained from hostile collision, by a sort of mutual consent; and excepting where the line of march brought the light troops into immediate proximity, or the occupation of a village produced a trifling fusilade, the grand movements of the rival hosts exhibited a “ceaseless march,” the leading columns pressing forward toward the Tormes, and the rear hidden from view “by dust and distance.”