  We develop a second order well-balanced finite volume scheme for compressible
Euler equations with a gravitational source term. The well-balanced property
holds for arbitrary hydrostatic solutions of the corresponding Euler equations
without any restriction on the equation of state. The hydrostatic solution must
be known a priori either as an analytical formula or as a discrete solution at
the grid points. The scheme can be applied on curvilinear meshes and in
combination with any consistent numerical flux function and time stepping
routines. These properties are demonstrated on a range of numerical tests.
