Observation of Fractional Charge of $\left(\frac{1}{3}\right)e$ on Matter

Measurements on niobium spheres which show unambiguously the existence of fractional charges of $\frac{1}{3}e$ are reported. Charge changes of $\frac{1}{3}e$ on particular spheres when they contact other surfaces are continually observed. Of 21 new measurements, four charges of $+\frac{1}{3}e$, four of $-\frac{1}{3}e$, and thirteen of zero are found. Extensive measurements and critical analyses have assured us that the background forces are either negligible or have been measured and taken fully into account.