  We have adjusted the Density Matrix Renormalization method to handle two
dimensional systems of limited width. The key ingredient for this extension is
the incorporation of symmetries in the method. The advantage of our approach is
that we can force certain symmetry properties to the resulting ground state
wave function. Combining the results obtained for system sizes up-to $30 \times
6$ and finite size scaling, we derive the phase transition point and the
critical exponent for the gap in the Ising model in a Transverse Field on a two
dimensional square lattice.
