Abstract
The ratio of the electrical resistivity at 293°k and 77°k has been measured as a function of thickness in the range 13 μ to 2 μ for annealed and cold-rolled super-purity aluminium. The annealed specimens show the dependence predicted by Fuchs' theory of surface scattering. The cold-rolled specimens show a deviation from Fuchs' theory which may be attributed to a loss of dislocations during thinning. The loss is estimated to be about 80%.