A magnetometer is a tool that is used at an excavation site, usually by a skilled technician. It is one of a group of tools that allow scientists to see things from far away or actually through layers of the earth (like an x-ray of the human body). These tools are usually called "remote sensing devices." The magnetometer measures the differences in magnetism that exist between soils of different types and materials made by humans. Because of these differences, fired clay materials, walls, and other evidence of ancient life can be "seen" using a magnetometer. Magnetometry has recently been used with some success in Nubia.
