"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. [Illustration: 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. "One of our baggage-mules was ahead, and right in one of the laderas he met a train coming the other way. I feared he would be thrown from the path into the great chasm, a thousand feet below, and you may be sure my face was full of anxiety. "To my surprise and delight the mule planted his four feet close together, and turned around in a space not more than a yard wide! Then he trotted back to join us, and I wanted to get down and hug him for his display of intelligence. "Federico told me to allow everything to my mule, and under no circumstances attempt to guide it in a dangerous spot. 'The mule knows every ladera on the mountains,' said he, 'and exactly where to place its feet. Never hurry it in the least, and never touch the reins no matter how much you are tempted to do so.'