Rates of mass transfer at inclined cylinders,with active ends were determined under natural convection conditions by measuring the, limiting current of. copper, deposition from acidified copper sulphate. Physical properties of the solution, cylinder dimensions and. inclination were varied to produce a ScGr range of 1.53 x 10(9) to 7 X 10(10). Under these conditions the data for different orientations were correlated by Sh = 1.075 (ScGr)(0.242). The characteristic length used in obtaining Sh and Gr was calculated by dividing the cylinder surface area by the cylinder perimeter projected onto the horizontal plane. At high CuSO4 concentrations a reasonable agreement was found the experimental rate of:mass transfer and that calculated by summing,the rate of mass transfer at individual surfaces of the cylinder. Deviations were. observed at low CuSO4. concentrations, and the possible causes of the deviations,were explained.