Ohio: Man in front of stockpile. Airplane flies overhead. Aerial photo of Cleveland Ohio. Aerial photography plane, with camera built in. All this to estimate the stock pile size. Darkroom technician. Light bulb illuminates. Projection room. Device to superimpose 2 negatives. All this to see a 3-D image using red and blue negatives. Operator wearing creepy glasses. He draws a topographic map. He is able to read the volume of the pile now.