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Henry, Morse, and the telegraph

Faraday was a true Philosopher; he did not submit any patents for any of his discoveries—prioritizing scientific pursuit over personal wealth—empowering others to drive creativity and invention. Soon people tried to find practical ways to use this new phenomenon of electromagnetism. The most intuitive application was simply creating stronger electromagnets. Back in 1823 Sturgeon had created the first electromagnet and over the following decade Joseph Henry dramatically improved the capabilities by making a magnet that could lift 3,000 lbs in 1832. Impressive, but not world-changing. Henry’s revolutionary contribution was much more subtle, and was in fact, a misnomer. Henry thought that magnets made with thick copper wire, activated by a large current, could be referred to as “quantity” magnets—which were best suited for lifting and attracting large objects—while magnets made with thin wire and many more turns were “intensity” magnets, which could be activated by a weak current sent through a very long wire. Today, we know this is a matter of “inductance” as a physical quantity. Interestingly, despite this significant contribution and demonstration of inductance, Faraday didn’t reference Henry in his Experimental Researches In Electricity, and today Henry isn’t much of a household name. Nonetheless, posterity was kind enough to give him a unit of measure.

Household name or not, Henry's “intensity” magnets are one of the most important world-changing inventions ever. They were capable of performing action at a distance, and therefore instant communication. Henry demonstrated the capabilities at The Albany Academy in 1831. His discovery was so subtle but so revolutionary that a thousand attempts to put it to practice sprung forth in a very short time. Over the next two decades Samuel Morse, an American inventor and artist, came out on top after fighting tooth-and-nail to develop methods, demonstrations, and enforce patents. Morse expresses his frustration on a letter to a friend in 1848: “I have been so constantly under the necessity of watching the movements of the most unprincipled set of pirates I have ever known, that all my time has been occupied in defense, in putting evidence into something like legal shape that I am the inventor of the Electro-Magnetic Telegraph! Would you have believed it ten years ago that a question could be raised on that subject?” Today, there is no question, Morse’s invention (facilitated by Henry) connected the world; it made the world a smaller place.

Source: Shock and Awe: The Story of Electricity. Presented by Jim Al-Khalili, BBC, 2011

Henry's magnet Telegraph patent drawing
Left: A powerful electromagnet built by American scientist Joseph Henry around the 1830s. Right: Figures from Morse's Telegraph patent
Public Domain

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Full disclosure, I may occasionally borrow a sentence from Will Durant's Story of Civilization. I absolutely love that collection!