Electric Light 20 x 30 Poster and similar items

20inch x 30inch Poster There are two kinds of electric lamps employed - the Arc lamp, and the Filamen lamp. In the arc lamp two carbon rods are placed with their points almost touching. The eletric current sparks across the gap, and an arc of glowing vapor is forms, the carbon points becoming white hot, and a dazzling light is produced. In the filiment lamp the electric current passes through an extremely fine wire which creates so high a resistance as to become white hot, thus giving out light. - There is a border around the image. Image size is correct.