To M. de Angelis I am also indebted for the copy of a MS. map, by Don Alvarez de Condarco, in which are laid down not only a recent journey of his own in 1837, to examine the mines in the Indian territory south of the Diamante, but the several marches of the troops, detached from Mendoza, in 1833, to co-operate with the forces from Buenos Ayres under General Rosas, in the general attack made upon the native tribes. I had already received, as I have mentioned in Chapter IX., through my friend Don Manuel Garcia, a map drawn by General Pacheco, showing the march of the principal division of that army, along the banks of the River Negro, from the Islands of Choleechel to the junction of the Neuquen. The routes in question have been very material to the laying down of the true courses of some of the many rivers which constitute the most important, though hitherto undescribed, features of that part of the continent:--and it is satisfactory to find that they are strikingly corroborative of the accounts, as far as they go, which I had already cited as given both by Villariño, by Don Luis de la Cruz, and our own countryman, Dr. Gillies. Thus far I have spoken of my geographical materials:--they will be found embodied in the accompanying map of the Republic by Mr. John Arrowsmith, who has spared no time or labour in its construction. In this he has also availed himself of the invaluable recent survey of Captain FitzRoy, to give the whole of the line of coast upon the very best authority. In the interior the various routes, which appear now for the first time collected together, have been all re-protracted from the original sources of information, whilst a careful re-examination of the labours of the Boundary Commissioners and of other authenticated authorities has enabled him to correct many errors of position which had crept, I hardly know how, into the latest maps, not excepting those compiled in the topographical department of Buenos Ayres. Upon the whole, although we have yet a vast deal to learn before any perfect map can be drawn of this extensive portion of the new continent, I trust that the present attempt will be regarded as no slight improvement upon our old geography of that part of the world[5].