inside and outside, were very thick and strong, plastered so carefully with a kind of white cement that they shone like enamel and led the Spaniards to think that these were palaces whose stones were plated with silver. Bright unfading colors were often used in decoration, and bricks were laid in ornamental courses. Ventilation was had by small apertures placed opposite each other and in a line with loopholes in the outer walls. Chimneys were un-> known to these ancient masons. The cooking for the community was done by a common fire, or by several fires if the clan was a large one.
Outside the large cities these communal dwellings were often grouped by the side of some stream and surrounded by cultivated fields and orchards, or oftener on some commanding hilltop. This was necessary in case of attack from hostile tribes. A group of these massive buildings surrounded by luxuriant trees must have presented a fine appearance. Some were from five to six hundred feet long, with wings. Towers two or three stories high were often added.
The building known as the Casa Grande, on San Miguel River, has walls eight feet in thickness and is supposed to have been seven stories high, with a front of eight hundred feet. Near this building was another, with rooms built around a square. The whole country in this region (one hundred and fifty miles north-west of Chihuahua) is full of Indian mounds, in which are found stone axes, mills for grinding corn, broken pottery, and other tokens that this was once the home of a large and thriving population.
In case of war the terraced roofs were heaped with missiles and bristled with defenders. When defeated, the survivors fled for refuge to the caves which abounded
