The term "dislocation" is used in several different senses in the
literature of mechanics. In the elassic work of VOLTERRA, WEINGARTEN,
and SOMIGLIANA, it refers to particular solutions of the equations of
linear elasticity, in which a con- tinuous field of strain does not
correspond, globally, to a continuous field of dis- placement. The
configuration of the body so obtained, even when that body is free of
all load, is subject to interior stress that does not vanish, and in
general no deformation of the body as a wh oIe can bring it into a
stress-free configuration. Nevertheless, if any sufficiently sm all part
of the body is considered by itself, a configuration for it in which the
stress is everywhere zero may be found at once. In this work
constitutiL"e assumptions provide the basic data. These consist in
prescribed stress-free configurations for each material point and in
prescribed elastic moduli governing the response to deformation from the
stress-free configuration at each material point. Everything follows
from these data, ineluding the dislocations present, if any. In
particular, the common boundary-value problems of linear elasticity may
be set and solved for the dislocated body.