Observation of fractional charge of (1/3)e on matter

Measurements on niobium spheres are reported which show unambiguously the existence of fractional charges of (1/3)e. We continue to observe charge changes of (1/3)e on particular spheres when they contact other surfaces. Of 21 new measurements we found four charges of +(1/3)e, four of -(1/3)e, and thirteen of 0. Extensive measurements and critical analyses have assured us that the background forces either are negligible or have been measured and taken fully into account