THE major part of thiook (Chapters I, II, III and V) is not very different from what was in the first two English editions (1959 and 1970).This is a natural result of the fact that the basic equations and conclusions of elasticity theory have long since been established. . The second edition included a chapter on the theory of dislocations in crystals, written jointly with A.M.Kosevich, which haeen only slightly changed in the present edition.