Measurements of the spatial structure of tokamak edge density fluctuations ñ have been made using compact probe arrays in the Caltech tokamak. The results indicate that the structure of ñ in the tokamak edge is characterized by very short auto-correlation times and short cross-correlation lengths, i.e. that the edge density fluctuations consist of small-scale 'turbulence'. The space-time structure of this ñ turbulence is consistent with several recent non-linear edge instability models. The structure of the local electrostatic potential is measured to be qualitatively similar to that of ñ, and local cross-correlation between ñ and indicates large outward radial particle transport similar to predictions of the edge instability models.