In this paper the secular equation for the Rayleigh wave speed in an incompressible orthotropic
elastic solid is obtained in a form that does not admit spurious solutions. It is then shown that inequalities on
the material constants that ensure positive definiteness of the strain-energy function guarantee existence and
uniqueness of the Rayleigh wave speed. Finally, an explicit formula for the Rayleigh wave speed is
obtained. ?? 2004 Acoustical Society of America.
