What lies beneath the ground? Our poor eyesight cannot penetrate even an inch into the soil, so for centuries, fortune-seekers have tried every way imaginable to see below the surface. Whether searching for mineral veins, groundwater, or buried treasure, people have looked for ways to avoid the plodding and backbreaking process of digging. They have followed dreams, seers, dowsing rods, and advice from the spirit world. When petroleum became an item of commerce, oil-hunters took to all these methods. Many built homemade inventions called doodlebugs, which they said could detect underground oil. It took a while, but science finally came up with its own toolbox of oil-finding methods in the early twentieth century. Finding oil is still expensive and risky, however. The old ways? They are mostly gone, but a few oil-dowsers still stride across fields with rod or pendulum, and no doubt people still consult dreams and psychics. And don’t pretend that you yourself haven’t wondered if that