ADOBE (4-clO'be), a Spanish-American word (often cor rupted to dobie) for the sun-dried clay used for building by the Indians in the arid regions of the south-western United States and northern Mexico (from Spanish adobar, to plaster). The use of such building material is said to have been anciently introduced into Spain from northern Africa. Soon after the discovery of America the method was imported into Peru, Mexico and other dry countries of the New World by the Spanish conquerors, who brought it as early as the 16th century to the Indians of New Mexico and Arizona. Most of the buildings connected with the Spanish missions in California, established in 1770-1823 were con structed of adobe. In Mexico and the south-western United States the name is not only applied to the bricks but also to the clay from which they are made, and, likewise, to structures built of this material. The usual method of making adobe is very simple. It consists of wetting a quantity of suitable clay, adding a small amount of chopped straw, hay, grass roots or other fibrous litter, mixing the materials with a hoe or a similar implement, and then trampling the mass with the bare feet. When brought to the proper consistency, the adobe is shaped with simple wooden moulds into bricks.
These vary greatly in size, in accordance with intended use, ranging from small forms about Sin. square and 2in. thick to large slabs I or 2yd. long, I f t.
wide and 6 to Bin thick. A com mon form for structural use is about I2in. wide, i6in. long and from 4 to 8in. thick. After being properly dried, adobes are laid in walls, like ordinary bricks, and joined with a mortar of the same material. Often the walls are smoothly finished inside and out with this mortar and given an outer coating of lime wash, which is frequently tinted with yellow or other colours.
In regions of scant rainfall adobe is serviceable in structures of one storey or other low buildings, having well-drained founda tions and non-leaking roofs with wide cornices and eaves. When protected against the action of water adobe walls will endure for many decades and sometimes for centuries. As adobe is a very poor conductor of heat and as walls made of it do not become frosty in cold weather or damp in a short rainy season, adobe structures are warm in winter and cool in summer, the interior temperature of the walls remaining remarkably constant. Since there has been a revival of adobe construction in the south western United States, particularly in California. In a modified form adobe is utilized also in Colorado and other States of the Rocky Mountain plateau, where, instead of being first made into bricks, the adobe is moulded directly into the wall, being applied and dried in successive layers. In the plateau region adobe is used chiefly for walls of stables, cattle sheds and chicken houses. In southern California substantial city homes have been con structed with adobe walls, made from materials available on the premises, and finished with waterproof plaster or stucco, thus making it possible, when so desired, to dispense with the wide cornices and eaves otherwise required in adobe structures. For the artistic adaptation of adobe to building construction see