Sep 13, 2016 ... read more
Bell's simpler circuit for the double coil metal detector. For SaleClick here to see more scientific instruments typical of late 1800s, that was available to DR. Bell and other inventors; coils, coil winders, coil resistance measurement equipment, Sine meters for measuring current, and batteries. read more
In 1881, Alexander Graham Bell invented the first metal detector. As President James Garfield lay dying of an assassin's bullet, Bell hurriedly invented a crude metal detector in an unsuccessful attempt to locate the fatal slug. Bell's metal detector was an electromagnetic device he called the induction balance. read more
One of his visitors during that time, Alexander Graham Bell, built a metal detector specifically to try to help find this bullet, but, sadly, his attempts were unsuccessful. It turns out the metal springs in the bed President Garfield was lying on confused the machine and rendered it essentially useless. read more