The term _hacienda_ has a double meaning, for it is applied both to the great estates and to the buildings. It is a patriarchal existence that is led by these landed proprietors. A thousand peons and more are frequently attached to the estate. Near the station of Villa Reyes is a great _hacienda_ which once controlled twenty thousand peons. These must be provided with homes, but a room fifteen feet square is considered sufficient for a family, no matter how large. Little furniture is needed, for they live out of doors mostly, and mats, which can be removed during the day, take the place of cumbersome beds. The _administrador_, who may be an Indian also, and other heads, live better and are housed in larger quarters. A church is always a part of the estate and a priest must be kept to furnish spiritual solace, as well as a doctor to administer to those whose bodies are infirm. Schools are also maintained by most of the proprietors to-day. The peon must be provided with his provisions each week and a little patch of ground for his own use. Around the buildings lie the cultivated fields, and from early morn until the shades of night have fallen, lines of burros are constantly passing in and out laden with wood, corn, vegetables, poultry, boxes of freight, and all the other items of traffic which are a part of the life of this great household. After piercing another of the mountain ranges which intersect the country from east to west, and traversing miles of fertile fields and gardens bearing semi-tropical fruits and vegetables, the road enters a valley and the city of San Luis Potosi is reached. Every country has its Saint Louis, but only one has a Saint Louis of the Treasure, and that is San Luis Potosi, the capital of the state of that name. It lies in a spreading plain of great fertility—made so by irrigation—whose gardens extend to the encircling hills that are rich in the mineral treasures which give the city its name. The San Pedro mines near here alone produce an annual output of several millions. These mines were revealed to Spaniards by an Indian who had become converted to Christianity. There is a mint here that coins several millions of dollars each year. [Illustration: MARKET SCENE IN SAN LUIS POTOSI]