Provides the code behind the Richardson Extrapolation blog post. I use the Poisson equation and the the method of manufactured solutions to test the increase in accuracy provided by this technique. First, an analytic and numerical solution are compared, and the order of convergence determined. Then, extrapolation is performed and a further comparison is performed. It is better! In short, we see an improvement of convergence from second order to fourth order. There is a corresponding increase in numerical accuracy.