the ground-floor. It was explained that this results from utilizing the earth on which the house stands, thus saving the expense of transporting the building material from outside the town.
In good houses a foundation is laid, varying from two to four feet in depth, formed of rough stones or broken fire-burned bricks, and piled up with mud and lime. This is carried up a foot or so above the ground, before the mud wall is commenced. In villages, where everything is rude, this foundation is made of any kind of rubbish that is found handy. This is a very interesting feature of mud architecture. Its object is no doubt to give strength where the wall would be liable to friction from the street traffic; and probably to prevent to a certain extent damp from rising. It would also be a safeguard against another serious danger—that is, if water were to accumulate by any chance round the base of the mud walls, and remain long enough to soak through, a very serious catastrophe might take place from the house tumbling
down. I can not recall to my memory any foundation of this kind in the mud houses of India. Village houses in the northwest of that country are usually built on a chabootra, which is a raised platform of mud, about a couple of feet in height, and this forms the floor of the house. This platform, by raising the foundation of the walls above the ground, may perhaps serve some of the purposes of the layer of stones in the Persian foundations.
The walls of Persian houses vary from two to four feet in thickness. This depends entirely on the quality of the house and the means of the builder. Thick walls make a cool house, and that is a desirable thing in the climate of Persia. If upper rooms are required, a greater strength of wall will be necessary. The mud is either laid on in layers or in the form of bricks. In garden walls hollow bricks are used for the top, to give lightness. These bricks are called sanduk, a word meaning "box," which is de-
- Sun-dried bricks are called khest in Persian; the fire-baked bricks are ajur or aujur. In Afghanistan, khist is used for both burned and unburned bricks. Gill, with a hard g, is Persian for mud.