The approximate value of the elementary electric charge had been known since 1874, when it was first computed by George Johnstone Stoney. After Stoney, other ex

The approximate value of the elementary electric charge had been known since 1874, when it was first computed by George Johnstone Stoney. After Stoney, other experiments had reduced the uncertainty with which the value was known, but it remained relatively high. The importance of the experiments of Robert Andrews Millikan consists in the fact that the uncertainty of the value of the elementary electric charge obtained by this method was much smaller than by any previous method (he claimed that it was better than one half of one percent, but he used wrong values for the viscosity of air, so his actual result was off by more than that, but still by less than one percent from the correct result).