Abstract: A plasma glow tube for displaying a bar of selectable length comprises an insulating enclosure filled with an ionizable gas. The enclosure may have flat opposing sides, the inside walls of which have conductive electrodes (preferably transparent) deposited thereover in a staggered pattern such that each electrode, except the end ones, is positioned between and equidistant from two opposing electrodes. The electrodes, except for the first and last electrodes which are DC coupled to the gas, are all covered with an insulating layer so that they are insulated from the gas. A potential difference, preferably in the form of a pulse, is applied between first and second end electrodes to ionize the gas therebetween and leave an inside wall charge adjacent said second electrode. A pulse is applied between the charged electrode and the next succeeding, opposite (third) electrode to ionize the gas therebetween and leave a charge on the third electrode, and so on.