A third-order rational approximant in a three-time level reccurence relation is applied successfully to the 'good' Boussinesq equation, already known in the literature. The resulting nonlinear finite-difference scheme, which is analysed for stability, is solved using a predictor-corrector (P-C) scheme, in which the predictor and corrector are both explicit schemes. This P-C scheme is accelerated by a modifed P-C (MPC) in which the already evaluated values are used for the corrector. The behaviour of both the P-C and MPC schemes is tested numerically on the single- and double-soliton waves, and the results from the experiments are compared with that in the literature.