Second, since the charge on the drop wasmultiplied more than four times withoutchanging at all the value of G, or the value ofe l , the observations prove conclusively that inthe case of drops like this, the drag which theair exerts upon the drop is independentof whether the drop is charged or uncharged.

How completelythe error arising from evaporation, convectioncurrents, or any sort of disturbances in theair, are eliminated, is shown by the constancyduring all this time in the value of the velocityunder gravity.