The History of the Metal Detector

By Daniel Bernzweig

The metal detector you’re using today has a surprisingly long history. In fact, the history of the metal detector is quite interesting and even involves a former president!

The First Metal Detector Appears

Back in the mid 1800s, after the invention of electricity, many scientists, scholars, and gold miners began experimenting with the idea of developing a machine that could locate metal buried underground. A device like this would be incredibly useful to the many prospectors still looking for gold after the “Gold Rush” and, as a result, could make the first person to perfect a metal detector very, very rich.

The first metal detector mentioned in history, however, actually has nothing to do with finding gold. Instead, it was used in an attempt to save President James Garfield after he was shot in Washington, D.C. on July 2, 1881, at the Baltimore and Potomac Railroad Station by Charles J. Guiteau. The President had been shot in the back, but, luckily, the wound did not kill him. Unfortunately though, doctors couldn’t locate the bullet and Garfield continued to suffer.

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. President Garfield finally died of infection from his wound September 19, 1881.

Improving the Original Metal Detector Design

Although the first metal detector didn’t help save the 20th President of the United States, the machine Alexander Graham Bell made was a viable metal detector and it went on to be the prototype for which all other metal detectors from that time forward have been based. Initially, these machines were really big, complicated, and ran on vacuum tubes. But, they were useful and continued to rise in popularity as a result. Most importantly these early metal detectors were used to find and clear landmines, and unexploded bombs across Europe after WWI and WWII.

At about the same time Gerhard Fisher, the founder of Fisher Metal Detectors, made an important discovery in his work on navigational systems. The radio beams he was using were being distorted every time there was an ore bearing rock in the area. As he was trying to work out the kinks in his system, he reasoned that this type of technology on a smaller scale might be useful as a metal detector. In 1925 Fisher was granted the patent on the first portable metal detector and he sold his first Fisher machine to the public in 1931.

The 1950s to Present Day Metal Detectors

Even though Fisher was granted the first patent on a metal detector, he’s just one of many who refined and perfected the technology currently being used in your metal detector. Another major player in the development of today’s metal detectors is Charles Garrett, the founder of Garrett Metal Detectors. An electrical engineer by trade, Garrett started metal detecting as a hobby in the early 1960s. After trying a variety of the machines on the market he couldn’t find one that was able to do all he wanted. So he began work on his own metal detector. After much research he was able to create a machine that eliminated oscillator drift, as well as several unique search coils he patented all of which essentially revolutionized metal detector design up to that point.

Other factors that have greatly influenced the development of metal detectors as we know them today include transistors - invented in 1947 by John Bardeen, Walter Brattain, and William Shockley - as well as discriminators, new search coil designs, and wireless technology. All of these things and more have allowed the metal detector to become the lightweight, portable, easy to use, deep seeking machines we know today.

With the number of players involved both professional and amatuer, as well as the rapid pace of technological advancement as a whole, the future of metal detectors is anyone’s guess. What can be almost guaranteed though is that metal detectors will continue to evolve and change in order to find even more treasure. Treasure hunters just don’t quit and, as you can see by the history of the metal detector up to this point, it’s these passionate, inventive people who’ve made metal detectors the machines they are today; and who’ll continue to influence the future of metal detecting.

© 2014 Detector Electronics Corp.