culty in the worst places in keeping the cattle going. This is chiefly because of the wind. In the Gran Chaco, whence the cattle have come, the southeast wind prevails. It is a soft, warm wind, dry or wet according to the season, and affects the cattle but little, for they do not graze upon wide open plains but upon patches of campo scattered here and there among woodland or forest tracts. On the Puna de Atacama, however, the northwest wind prevails. Though the mornings are calm, the wind rises to gale strength in the late forenoon and by mid- afternoon is blowing with great violence, carrying sand and dust in considerable volume and weakening man and beast by its great force and low temperature. At times it blows all day at freezing or just a little above freezing temperatures. When it comes laden with snow or dust it is called viento blanco and envelops the herds of cattle and the horsemen and makes going exceedingly difficult. When it blows with greatest violence the cattle tend to break and run, seeking shelter one by one or in groups under the lee of large rocks or ridges or in tributary valleys off the main trail. To keep the cattle together and not to lose ground by having them run before the wind is often a difficult task, though it becomes less difficult as the western border of the mountains is reached, for the beasts are then so tired and enfeebled that they are glad to lie down at every opportunity. Thus they arrive at the western crest of the cordillera and begin the long descent toward the desert settle- ments, particularly that of San Pedro de Atacama.
It takes thirteen to fourteen days for cattle to be driven from Salta to San Pedro de Atacama. They wait at San Pedro one or two days, according to the need for beef at the nitrate establishments, as well as their own condition, which depends largely upon the weather they have experienced in crossing the Puna. The days of waiting are called “la tablada.” In this time the cattle are fed liberally, and if any of them are ailing or footsore they receive the attention of a veterinary. From San Pedro it takes three days to drive them to the nitrate establish- ments, and the men return in two days more, receiving 45 pesos Chilean for the five days’ work. On the return they rest from three days to a weck at San Pedro or work in the fields
