I suspect the plains of Patagonia, like those of Australia, are traversed by many watercourses, which only perform their proper parts at certain periods.

Probably this is the case with the water which flows into the head of Port Desire, and likewise with the Rio Chupat, on the banks of which masses of highly cellular scoriae were found by the officers employed in the survey.
As it was early in the afternoon when we arrived, we took fresh horses and a soldier for a guide, and started for the Sierra de la Ventana.

This mountain is visible from the anchorage at Bahia Blanca; and Captain Fitz Roy calculates its height to be 3340 feet--an altitude very remarkable on this eastern side of the continent.

I am not aware that any foreigner, previous to my visit, had ascended this mountain; and indeed very few of the soldiers at Bahia Blanca knew anything about it.

Hence we heard of beds of coal, of gold and silver, of caves, and of forests, all of which inflamed my curiosity, only to disappoint it.