Amongst the most interesting perhaps of these I may mention—
The original Diaries of Don Juan de la Piedra, sent out from Spain, in 1778, to explore the coasts of Patagonia.
A series of papers drawn up by his successors the Viedmas, the founders of the settlements at San Julian and on the Rio Negro.
The original Journal of Don Basilio Villariño, who, in 1782, explored the great river Negro, from its mouth in lat. 41° to the foot of the Andes, within three days' journey of Valdivia, on the shores of the Pacific.
The Narrative, by Don Luis de la Cruz, of his Journey through the territory of the Indians and the unexplored parts of the Pampas, from Antuco, in the south of Chili, to Buenos Ayres, in 1806.
The Diary of Don Pedro Garcia's Expedition to the Salinas, in 1810, given me by my most estimable friend, his son, Don Manuel.
Together with a variety of other unpublished accounts of the Indian territories south of Buenos Ayres, principally collected by order of that government, with a view to the extension of their frontiers.
The substance of these papers, all which relate to the southern and least known parts of the New Continent, will be found in Chapters VII., VIII., and IX.
Respecting the eastern or Littorine provinces of the Republic, as I have ventured to call them, the most valuable data existing are, first, those collected by the Jesuits, and next, the various reports and memoirs drawn up by the officers employed to fix the boundaries under the treaties between Spain and Portugal of 1750 and 1777. The especial qualifications of the individuals, particularly of those employed in the last case, the length of time spent upon the service (more than twenty years), and the enormous expenses incurred by Spain in the endeavour to complete that survey, led to a large accumulation of invaluable geographical data respecting extensive ranges of country never before properly examined, much less described.
Nor were the labours of the officers in question confined to the frontiers. They fixed, as I have stated in Chapter VIII., all the principal points in the province of Buenos Ayres, made surveys of the great rivers Paranã and Uruguay, and of their most important tributaries; and drew up many notices of great interest respecting the countries bordering upon the higher parts of the Paraguay, which the pretensions of the Portuguese in that direction rendered it requisite for them to explore with more than ordinary care and attention[2].