In the Millikan oil drop experiment the magnitude of the
elementary charge was measured to be 
C.
The tabulated value is 
C.
The elementary charge was found by examining the motion of oil
droplets with radii 
cm between a pair of highly charged
capacitor plates. Although the droplets typically contained
protons, they were found to have net charges of only 2 to
15 times the elementary charge. Such low charges enabled observation
of the quantization of charge.