Glueball Masses in Quantum Chromodynamics

We review the recent glueball mass calculations using an efficient method for solving the Schr\"odinger equation order by order with a scheme preserving the continuum limit. The reliability of the method is further supported by new accurate results for (1+1)-dimensional $\sigma$ models and (2+1)-dimensional non-abelian models. We present first and encouraging data for the glueball masses in 3+1 dimensional QCD.