RICHARDSON, MATHEMATICAL MODELER

On the occasion of the 70th anniversary of Richardson's book Weather P rediction by Numerical Process (Cambridge University Press, Cambridge) , a review is given of Richardson's scientific work. He made lasting c ontributions to very diverse fields of interest, such as finite-differ ence methods and related numerical methods, weather forecasting by com puter, turbulence, international relations, and fractals. Although he was an original experimenter, the main present-day interest is in his mathematical modelling work.