G. I. Taylor's theory of diffusion by continuous movements and the A. Einstein equation of diffusion were applied to eddy diffusion of particles in a two dimensional field of homogeneous turbulence produced by a broad shallow channel with extreme bottom roughness. A simple method of determining the Lagrangian eddy size, eddy diffusivity, turbulence intensity, and mixing length was devised. Application of this technique provided experimental verification of the A. N. Kolmogoroff similarity principle that relates eddy diffusion, the rate of energy dissipation, and the Lagrangian eddy scale.