The motion of a single gas bubble rising steadily in an uncontaminated Newtonian viscous fluid of infinite extent is reviewed. Using experimental data gathered from the literature over the past century, a data bank is set up for bubble velocities as a function of their diameters. These data provided a very broad range of liquid properties and bubble hydrodynamic regimes as density (722 - 1,380 kg/m(3)), viscosity (2.2 x 10(-4)-18 Pa . s), surface tension (15.9 -91.0 mN/m), Reynolds number (1.9 x 10(-7)- 1.1 x 10(4)), and Morton number (1.0 x 10(-11)-1.0 x 10(7)). From a dimensional analysis, a single equation is proposed to pr edict bubble velocities. The simplicity and good precision over the whole range of parameters facilitate its use in design calculations of chemical engineering.