"I wondered how it would be possible to separate the animals of the different trains, but soon found out.
"As each arriero completed his saddling he led out his madrina, or bell-mare, and tinkled her bell. Instantly his mules followed her, separating themselves from the rest of the herd without the least difficulty. Federico told me it is the bell rather than the mare which forms the attraction, as the mules will follow the bell on a strange mare but will not follow their madrina with another bell. When the mules are turned out to graze they always keep near the madrina, and their manifestations of devotion to her are constant. When she is in danger they have been known to form a circle about her and, with heels outward, make a vigorous defence.
"My saddle-mule was a perfect 'amadrinado,' in the language of the arrieros, or thoroughly trained to follow the madrina's bell. If I fell behind the train at any time, and especially if the bell could not be heard, the beast became restive, and was evidently much alarmed. If I dismounted, for even a minute, it was necessary to keep a strong hold of the bridle, and there would generally be so much kicking and plunging that I needed the aid of the arriero or a peon to mount again.
"The table-land of Uspallata continues for eight or ten miles, till the valley of the Pichiuta River is reached. We ascended this valley, for several miles and then turned across an intervening ridge to the Mendoza River; the Pichiuta is a clear, sparkling stream of excellent water, and there is plenty of pasturage and fuel along its banks, while the water of the Mendoza is muddy and has a brackish taste.
A MOUNTAIN CAÑON.
"Here let me remark that there is a wonderful difference between the rivers of the eastern and western slopes of this part of the chain of the Andes. On the Chilian side the streams are nearly all clear and pure, while on the Argentine side they are mostly muddy, and so impregnated with salt and lime as to be unfit for drinking or cooking purposes. The banks of the small streams are nearly always covered with an incrustation of impure saltpetre, and sometimes the water is so bad that cattle are poisoned by it.
"On the ridge between the two rivers we had our first real dangers of mountain travelling. There are several laderas, or places where the road is cut into the side of a mountain, and so narrow that two loaded mules cannot pass. There are spaces where the path is widened a little, and it is customary for trains, moving in opposite directions, to watch for each other and avoid meeting in the narrow and most dangerous spots.