One of the first attempts made by the Independents to acquire accurate data respecting the country to the south of the Salado appears to have been in 1810, on the occasion of one of the periodical expeditions to the great salt lakes in the south. Those expeditions formed a singular exception to the ordinary supineness and indisposition of the Spaniards to cross their own frontiers. They consisted of large convoys of waggons dispatched under direction of the municipal authorities to collect salt for the yearly supply of the city, escorted by a military force to protect them from the Indians. Of their apparent importance some idea may be formed from one, of which an account has been preserved, and which took place during the time of the Viceroy Vertiz, in 1778, composed of 600 waggons, with 12,000 bullocks, and 2600 horses, and nearly 1000 men to load them, besides an escort of 400 soldiers. The Indians, on these occasions, were propitiated by suitable presents, and, as the caravans never deviated from their object, they became habituated to them, and, instead of regarding them with jealousy, in general rather looked forward with eagerness for the annual tribute in the shape of presents which the Spaniards were ready to pay them for an unmolested passage across their territories. They even lent the people their assistance at the salt-lakes to load their waggons in exchange for beads and baubles from Buenos Ayres. The Viceroy occasionally attached some pieces of artillery to the troops, and generally availed himself of the opportunity to make a salutary display amongst the savages of the military discipline and power of the Spanish soldiers, which no doubt had its due effect; but no one thought of turning these expeditions to any further account:--they never departed from the same direct and beaten track across the pampas, and not the slightest pains were taken to collect any further information respecting the country beyond, at least in the time of the Old Spanish rule. The members of the National Government, set up in 1810, were animated by a different spirit: they foresaw with the dawn of their new destinies the prospect of their becoming a commercial people, and the consequent necessity of giving such encouragement to the extension of their pastoral establishments as would tend to the multiplication of the staple commodities of the country. The extension of their frontiers, and their due protection by military posts were consequently among the first objects of their attention; and when the annual expedition to the Salinas was about to set out, they took care to select an officer for the command of it qualified to reconnoitre the country and to collect such information as might assist them in determining upon their future plans for an extension of their territorial jurisdiction.