It should be evident, at this stage in the book, that the durability and longevity

of an earth wall will be dependent as much upon the raw material originally

employed as it is on the degree of care with which the building was con-

structed. It would perhaps be reasonable to assume that few buildings that

were built in haste, with little care and using unsuitable materials, still survive.

However, experience has shown that such buildings do exist, though they