UP THE URUGUAY RIVER. 221
by iufiltration : similarly petrified cowhorns are said to be found on the upper Parana. Much of the sandstone grit is blackened and polished by the force of the rapids, iron-revetted like the rocks in many of the West African and east South American rivers. In the great Platine valley, I found the crust only here.
My desire to see Uruguayana and the upper Uruguay was thwarted by circumstances. The roads were knee deep in mud, and the weather was detestable, now seething with sun and mist, then raw and damp with the south wind and Gariia, the river fog. The river was falling ra- pidly, the wretched little steamer Chata or raft which was detached to make the passage, had been forced back to repair an injury done by the nearest rapid, and no one ex- pected her to make her destination, whilst M. Rivas, the owner, crowded her with passengers, and demanded uncon- scionable fares. I therefore took heart of grace, and merrily returned to Buenos Aires.
Uruguayana, a fourth-rate Brazilian town in the Upper Uruguay, won a name for itself during the last Paraguayan war. Here fell to pieces the Corps d^Armee of the east, which Marshal-President Lopez had despatched under Colonel Estigarribia, to sweep the riverine valley, and to effect a junction with the western column. The Paraguayan leader had made the fatal mistake of leaving one-third of his forces on the right bank of the stream, which now^here allows communication without boats ; and this second divi- sion of 2500 men, under Colonel Duarto, was annihilated with the exception of 300 prisoners by the 13,000 allies, on 17th August, 1865, at the Battle of Yatay (the Brazilian Jatahy). On June 11, the Paraguayan cause had been greatly shaken by the defeat of her navy at Riachuelo, and Colonel Estigarribia found it advisable to fall back upon Uruguayana. This town was presently invested by the
