Written on back: "April 1970; 20,000 VOLTS -- That's what this water-drop electrostatic generator built by Jim Christensen, a ninth grader at Andrews University Junior High, will produce. The generator, which won Jim the grand award in the junior high science fair at AU, consist of three tin cans plus hoses and connecting wires. When drops of water from the two hoses at top pass through the metal rings on center board, an electrostatic difference amounting to 20,000 volts is set up between the cans at bottom. Jim is the son of Mr. and Mrs. Bruce Christensen, 2514 Lemon Creek Road, Berrien Springs. The science fair was coordinated by Clifton Keller, science and mathematics teacher at the AU Junior High."