It was late when the light division descended the rough side of the Aldea Lengua mountain to cross the river, and the night came suddenly down, with more than common darkness, for a storm, that common precursor of a battle in the Peninsula, was at hand. Torrents of rain deepened the ford, the water foamed and dashed with encreasing violence, the thunder was frequent and deafening, and the lightning passed in sheets of fire close over the column, or played upon the points of the bayonets. One flash falling amongst the fifth dragoon guards, near Santa Marta, killed many men and horses, while hundreds of frightened animals breaking loose from their piquet ropes, and galloping wildly about, were supposed to be the enemy’s cavalry charging in the darkness, and indeed some of their patroles were at hand; but to a military eye there was nothing more imposing than the close and beautiful order in which the soldiers of that noble light division, were seen by the fiery gleams to step from the river to the bank and pursue their march amidst this astounding turmoil, defying alike the storm and the enemy. [Sidenote: See Plan 3.] The position now taken by the allies was nearly the same as that occupied by general Graham a month before, when the forts of Salamanca were invested. The left wing rested in the low ground on the Tormes, near Santa Marta, having a cavalry post in front towards Calvariza de Abaxo. The right wing extended along a range of heights which ended also in low ground, near the village of Arapiles, and this line being perpendicular to the course of the Tormes from Huerta to Salamanca, and parallel to its course from Alba to Huerta, covered Salamanca. But the enemy extending his left along the edge of the forest, still menaced the line of communication with Ciudad Rodrigo; and in the night advice came that general Chauvel, with near two thousand of Caffarelli’s horsemen, and twenty guns, had actually reached Pollos on the 20th, and would join Marmont the 22nd or 23rd. Hence Wellington, feeling that he must now perforce retreat to Ciudad Rodrigo, and fearing that the French cavalry thus reinforced would hamper his movements, determined, unless the enemy attacked him, or committed some flagrant fault, to retire before Chauvel’s horsemen could arrive.