  Balance equations are derived from Enskog's kinetic equation for a
two-dimensional system of hard disks using Grad's moment expansion method. This
set of equations constitute an extended hydrodynamics for moderately dense
bi-dimensional fluids. The set of independent hydrodynamic fields in the
present formulations are: density, velocity, temperature {\em and
also}--following Grad's original idea--the symmetric and traceless pressure
tensor $p_{ij}$ and the heat flux vector $\mathbf q^{k}$. An approximation
scheme similar in spirit to one made by Grad in his original work is made. Once
the hydrodynamics is derived it is used to discuss the nature of a simple
one-dimensional heat conduction problem. It is shown that, not too far from
equilibrium, the nonequilibrium pressure in this case only depends on the
density, temperature and heat flux vector.

Statistical Mechanics