Lustrum censors in the Campus Martius, after the taking of the census was over. As this purification took place only once in five years, the word lustrum was also used to designate the time between two lustra. The first lustrum was performed in 566 BC by King Servius, after he had completed his census, and afterwards it is said to have taken place regularly every five years after the census was over. In the earliest period of the republic, the business of the census and the solemnities of the lustrum were performed by the consuls. The first censors were appointed in
A Is for Atom tighter editing, new music and a focus on nuclear power as opposed to nuclear bombs. A narrator is relating what is an atom and how atomic energy can be harnessed by man to produce "limitless" energy. Dr. Atom (a caricature with an atom for a head) then explains the similarities between the solar system and atomic structure. He then goes on to relate how the atom is made up of protons, neutrons, and electrons. After this, the narrator explains how there are more than 90 elements with many possible isotopes for each. The history of atomic energy is then overviewed