In the mountains, the shoeing of mules and horses is frequently a matter of much difficulty; and it is advisable for the traveller to acquire the art, and furnish himself with needful implements, before leaving the more civilized part of the country. Farriers are only to be found in the large Indian villages, and it is common to ride fifty or sixty leagues without meeting with one. In the village of San Geronimo de Surco, the innkeeper is the only blacksmith, and Dr Tschudi, whose horse had cast a shoe, was compelled to pay half a gold ounce (upwards of thirty shillings) to have it replaced. This was one half less than the sum at first demanded by the exorbitant son of Vulcan, who doubtless remembered the old Spanish proverb, "for a nail is lost a shoe, for a shoe the horse, for the horse the horseman."[9] The doctor took the hint, and some lessons in shoeing, which afterwards stood him in good stead. It is a common practice in Peru, on the sandy coast, and where the roads permit it, to ride a horse or mule unshod for the first four or five days of a journey. Then shoes are put on the fore feet, and a few days later on the hinder ones. This is thought to give new strength to the animals, and to enable them to hold out longer. On the mountain tracks, the wear and tear of iron must be prodigious, as may be judged from the following description of three leagues of road between Viso and San Mateo, by no means the worst bit met with by our traveller. "The valley frequently becomes a mere narrow split in the mountains, enclosed between walls of rock a thousand feet high. These enormous precipices are either perpendicular, or their summits incline inwards, forming a vast arch; along their base, washed by the foaming waters of the river, or higher up, along their side, winds the narrow and dangerous path. In some places they recede a little from the perpendicular, and their abrupt slopes are sprinkled with stones and fragments of rock, which every now and then, loosened by rain, detach themselves and roll down into the valley. The path is heaped with these fragments, which give way under the tread of the heavily laden mules, and afford them scanty foothold. From time to time, enormous blocks thunder down the precipice, and bury themselves in the waters beneath. I associate a painful recollection with the road from Viso to San Mateo. It was there that a mass of stone struck one of my mules, and precipitated it into the river. My most important instruments and travelling necessaries, a portion of my collections and papers, and--an irreparable loss--a diary carefully and conscientiously kept during a period of fourteen months, became the prey of the waters. Two days later the mule was washed ashore; but its load was irrecoverably lost. Each year numerous beasts of burden, and many travellers, perish upon this dangerous road. Cavalry on the march are particularly apt to suffer, and often a slip of the horse's foot, or a hasty movement of the