The Salteños boast that within their own territory they possess every climate, from extreme heat to the most intense cold; and, consequently, that they can rear almost every production of nature; for although directly under the tropic, the mountain ranges rise in some places to the height of perpetual snow, counteracting the sun's influence more or less according to the elevation. Thus whilst in all the department of Oran, in the east of the province, the tropical sun has its full influence, under the same latitude in the west, in the mountain districts of Rosario and Rinconada, the cold is intense. In the intermediate valleys the climate is temperate and agreeable. It is in these valleys that the population is chiefly located: they are for the most part highly fertile, being watered by many small rivers and streams, which, running eastward from the mountainous districts, fall into the Salado and Vermejo, which have already been described as the principal aqueducts of these Upper Provinces. Indeed it is in this province that both these noble rivers may be said to have their origin, of which I shall venture to give the following account, chiefly from data published by Colonel Arenales, son of the late Governor of Salta, and now at the head of the topographical department of Buenos Ayres. As a general observation it may be stated that the tributaries of the Salado all run south, whilst those of the Vermejo will be found to the north of the city of Salta, as may be seen on reference to the map.