 This series entry starts with the narrator saying  No more lost airplanes.  He then explains how the first practical airplane flight recorder sends signals back to a control center, where the plane s position is plotted by lights on a large board. Other reports include the production of dry ice from gas reserves near the Salton Sea, an early telephone answering machine, pearls produced by abalone at the Scripps Institution of Oceanography, and the structure of various crystals under the microscope.