Let G be a bounded
domain in the complex plane and let u(z) be continuous on Ḡ. In this paper
we study the boundary modules of continuity, ω(δ), of u on ∂G and the
modulus of continuity, ω(δ), of u on Ḡ. We investigate the extent to which the
inequality “ω(δ) ≤ω(δ)” holds when u is harmonic on G and show that
the precise formulation of such inequalities depends on the smoothness of
∂G.