Ignorance of the Buenos Ayreans respecting the lands south of the Salado previously in their Independence. Colonel Garcia's expedition to the Salt Lakes in 1810. The Government of Buenos Ayres endeavours to bring about an arrangement with the Indians for a new boundary. Their warlike demonstrations render futile this attempt. March of an army to the Tandil, and erection of a Fort there. Some account of that part of the country. The coast as far as Bahia Blanca examined, and extension of the frontier-line as far as that point. The hostility of the Indians makes it necessary to carry the war into the heart of their Territories. General Rosas rescues from them 1500 Christian captives. Detachments of his army occupy the Choleechel, and follow the courses of the River Negro and of the Colorado till in sight of the Cordillera. Having given some account of the explorations of the Old Spaniards beyond Buenos Ayres, I shall now proceed to state what has been done by their successors since their independence. It is inconceivable the ignorance which, up to a very recent period, existed amongst even the higher classes of the people of Buenos Ayres respecting the Indian territories which immediately bounded their own lands to the southward. It is indeed only by a laborious investigation of the history of their frontiers, and of the steps taken from time to time to advance them, that we can even now obtain any tolerable notion of the physical features of that part of the continent. This, however, is worth the trouble, as it will furnish materials for laying down a considerable portion of country hitherto most imperfectly and erroneously described in all existing maps.