The political isolation of Buenos Aires between 1852 and 1862, during the time when the first concessions were issued, made upon the railway system an impression that would not be effaced until twenty-five years afterwards. It was not until 1886 that Rosario was connected by rail with Buenos Aires. The line to Mendoza and Chile, begun in 1870 (F. C. Andino), joins the line from Rosario to Cordoba. It reached Mendoza at the foot of the Andes before going on to Buenos Aires; and it was in 1888 that the Pacific railway was completed between Buenos Aires and Villa Mercedes, and established direct communications between the capital and the province of Cuyo. The line from Rosario to Cordoba is, therefore, the chief branch round which the Argentine system developed. It is remarkable that at the time of the original concession in 1855 a westward extension was contemplated, and that there was some idea of making it a stage in a trans-Andean. The first concessionaire, Wheelwright, had made the oldest railway in South America, from Caldera to Copiapo, in Chile in 1851. The 1855 concession authorized Wheelwright to extend the Cordoba line westward and link it with the Copiapo line. When he opened the Cordoba station in 1870, Wheelwright, not suffering himself to be discouraged at the slowness with which the line had crossed the Pampa, still said that the goal was the Pacific, by way of Rioja, Copacabana and the San Francisco pass. This ambitious programme deserves to be recalled, if only as a reminiscence of the former orientation of the trade of Rioja and Tinogasta toward the Pacific, and as a proof of the importance, in the imagination of the men of that generation, of the old trans-Andean roads from north-western Argentina. Even before the Rosario line had reached Cordoba, it had been continued northward as far as Tucuman. The work was pushed vigorously, and Tucuman was reached in 1875. The Cordoba-Tucuman line was the first to be constructed entirely in the region of the scrub, and _quebracho_ sleepers were then used for the first time. The earliest lines of the Buenos Aires province and the Argentine had, on the model of the Indian railways, a gauge of 5 feet 8 inches, but the Central Cordoba, from Cordoba to Tucuman, had a narrow gauge of forty inches. Hence goods coming from Tucuman had to be transferred at Cordoba. At the same time (1875) the line from Concordia to Monte Caseros was opened, and this made it possible to avoid the rapids of the Uruguay, which was to be a source of supply to the whole Mesopotamian system. Its gauge was fifty-seven inches. Differences of gauge are, and will continue to be, one of the characteristics of the Argentine system.