importance of mud in connection with building and architecture first attracted my attention. I had to pass from Tehran eastward, through Khorassan and into Afghan Turkestan. Along the whole of this route mud is the building material. Some of the serais—that is, caravan serais for the accommodation of travelers—are of burned brick, but these are about the only exceptions. Not only villages, but large towns, are built of mud or sun-dried brick. The defensive walls are of the same material; even such large towns as Sabzawar, Nishapur, Meshed, and New Sarrakhs are fortified with walls of this kind. On realizing this almost exclusive use of one building material, in one region, my mind naturally recalled what I had seen in India, where, although stone and fire-burned
brick are largely used, yet the villages are over very large districts wholly constructed of mud. In Afghanistan it is the same. The fort at Peshawer, which was Afghan territory up to Runjit Singh's time, is a mud one. Jellalabad is surrounded by a mud wall. From the Khyber Pass to Tehran the towns and their defenses, as well as the villages, are almost identical in their material as well as in their general appearance.
These statements show that over a large geographical space in the Eastern world the building material at the present day is almost exclusively mud. I have been thus far speaking of what I have seen with my own eyes. To this may be added the practice of other countries. I believe that it is the same over most of Central Asia. It is now accepted that in Mesopotamia it was largely employed; and we know that in Egypt, from the earliest times to the present day, it has been the principal means employed in structural erections. It was largely used in Greece in ancient times, and also in Spain. It was known in South America and all along the Pacific coast, from Peru to San Francisco. The word "dobies," for sun-dried bricks, is a familiar term—this is derived