One of the co-discoverers of plutonium, Dr. Glenn T. Seaborg, holds a historic device: a balance which was used in research during World War II for the first weighing of the new man-made element. The amount weighed was tiny, only about on-millionth of the weight of a dime. Suspended from the upright bar of the balance is a hairlike quartz fiber, too fine to show up in the picture. The Nobel laureate Dr. Seaborg, who acted as the Chairman of the U.S. Atomic Energy Commission, worked with colleagues in an experiement that positively identified the trans-uranium element which, like uranium, is fissionable and thus of tremendous present and potential benefit to mankind.