  Consider a one-parameter family of smooth projective varieties X_t which
degenerate into a simple normal crossing divisor at t=0. What is the dual
variety in the limit? We answer this question for a hypersurface of degree d
degenerate to the union of two hypersurfaces of degree d_1 and d-d_1 meeting
transversely. We find all the irreducible components of the dual variety in the
limit and their multiplicities.
