This author gives the heights of the Passes.) As the observations have been chiefly made in summer, this wind must be an upper and return current.

The Peak of Teneriffe, with a less elevation, and situated in latitude 28 degrees, in like manner falls within an upper return stream.

At first it appears rather surprising that the trade-wind along the northern parts of Chile and on the coast of Peru should blow in so very southerly a direction as it does; but when we reflect that the Cordillera, running in a north and south line, intercepts, like a great wall, the entire depth of the lower atmospheric current, we can easily see that the trade-wind must be drawn northward, following the line of mountains, towards the equatorial regions, and thus lose part of that easterly movement which it otherwise would have gained from the earth's rotation.

At Mendoza, on the eastern foot of the Andes, the climate is said to be subject to long calms, and to frequent though false appearances of gathering rain-storms: we may imagine that the wind, which coming from the eastward is thus banked up by the line of mountains, would become stagnant and irregular in its movements.
Having crossed the Peuquenes, we descended into a mountainous country, intermediate between the two main ranges, and then took up our quarters for the night.

We were now in the republic of Mendoza.
The elevation was probably not under 11,000 feet, and the vegetation in consequence exceedingly scanty.