What is Metal detector?
A '''metal detector''' is a [[tool]] a person can use to help find [[metal]] nearby. It is useful for finding metal within other objects, or for finding metal underground. Most metal detectors will make a sound or have a needle move on a sensor in order to show where objects are. This tells how close you are to an object - for example, by making a higher-pitched sound when you are closer to an object. ==History of the metal detector== [[Alexander Graham Bell]] invented a kind of metal detector in [[1881]] when he was trying to find the bullet in President [[James Garfield]]'s body after he had been shot. The metal detector worked but it was confused between the bullet and a coiled bed-spring on which the President lay. Gerhard Fischer made a better version in the 1920s but the detector got confused when someone was approaching [[ore]]-bearing rocks. He was given a [[patent]] in 1925. A businessman named Shirl Herr had earlier tried to get a patent for a metal detector but was not given one until 1928. ==Uses== A metal detector can be used by [[archaeologist]]s for finding things like metallic [[coin]]s, [[bullet]]s, and [[jewellery]] underneath or inside a surface. [[Category:Archaeology]] [[Category:Measuring tools]]