  The Chern--Simons term is used in the geometric theory of defects. The
equilibrium equations with $\delta$-function source are explicitly solved with
respect to the $SO(3)$ connection. This solution describes one straight linear
disclination and corresponds to the new kind of geometrical defect: it is the
defect in the connection but not the metric which is the flat Euclidean metric.
This is the first example of a disclination described within the geometric
theory of defects. The corresponding angular rotation field is computed.
