The new detectorists Nikoline Bohr, 32, a member of the Ring Finders network, with her metal detector at a construction site in Nantucket, Mass., May 17, 2021. As an old outdoor hobby draws new followers, metal detectors are sweeping the country. Maddie Malhotra/The New York Times. by Alexandra Marvar (NYT NEWS SERVICE) .- People have been metal detecting since 1881, when Alexander Graham Bell invented a device to find the bullet lodged in President James Garfield. But it took several more decades for recreational metal detectors devices that resemble sort of a skillet on the end of a pole, as one newspaper put it in 1927 to develop a serious cult following.