In a particular early run (1911), Millikan observed that the following measured charges, among others, appeared at different times on a single drop:

.

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Let the value of the quantum of charge be e. Therefore, the values of the charges on oil drops measured by Millikan have to be integral multiples of e.

In the ascending order of the values given in the data above we write

where and is some integer.

Similarly, where and is some integer, and so on.

We work out the ratios

and

We now find the smallest integer for which will be integers. From the data above, we note that the solution is

The value of quantum of charge e that can be deduced from the above data of the Millikan’s experiment (1911) is