Blend times and power consumption have been measured for Newtonian and pseudo- plastic fluids in agitated, baffled vessels with diameters of 0.30,0.61 and 1.83 m. The viscosities of the fluids were selected to give a range of Reynolds numbers between 200 and 105. Four impellers were tested with diameters between T/3 and T/2 positioned at T/3 clearance above the lowest point of the vessel base. The impellers were typical of those found in the chemical industry.