  We review the continuous theory of dislocations from a mathematical point of
view using mathematical tools, which were only partly available when the theory
was developed several decades ago. We define a space of dislocation measures,
which includes Hausdorff measures representing the dislocation measures of
single dislocation curves. The evolution equation for dislocation measures is
defined on this space. It is derived from four basic conditions, which must be
satisfied by the model.
