A complete set of contour integrands is derived for the primary BIE's
of elastostatics and potential flow. Because of surface-independent pr
operties of vector potentials, these apply to non-planar surfaces and
can be differentiated at the fixed point, producing contour integrands
for both the so-called hypersingular and Cauchy singular parts of the
gradient BIE. The results are applicable to 'far field', 'near field'
and 'on surface' cases. Numerical examples demonstrate exact agreemen
t with surface quadrature, and contour plots are given showing variati
on of the hypersingular integrands in 'on surface' cases.