Siemens revolutionised electricity generation, invented the moving-coil loudspeaker, did much to advance international telegraphy, and helped found the electrical engineering industry. His gold and silver electro-plating technology was sold by his brother Wilhelm (later William) to a Birmingham industrialist. Helmholtz, a lifelong friend, was met initially in the circle around Siemens’ teacher Magnus (who, impressed by Siemens’ dynamo, offered to make a public presentation about it). Siemens, together with Helmholtz, Clausius, Kirchhoff and Wiedemann, was active in the Physical Society of Berlin, founded by du Bois-Reymond (who became a good friend).
The prolific Edison invented the phonograph, popularised electric light, and (among much else) founded the world’s first industrial research lab. Acheson, Dickson, Hammer and Tesla all worked with or under him, though he never appreciated Tesla’s genius. Marey’s meeting with him helped inspire the kinetoscope, while Muybridge’s led to the first ever moving image with sound (Muybridge despairing at its crudeness). Eastman and Edison clashed over X-rays but successfully collaborated on photographic and movie technology. Edison ignored his family and had few friends, though Eastman and Ford became close.
Baskerville encouraged Boulton’s sense of experiment. Watt, always the more cautious, joined him in a notable 25-year manufacturing partnership. Of other Lunar Society colleagues, Wedgwood (the other great enlightened industrialist of the age) and Darwin were good friends, Small his confidant and doctor. Flaxman and Murdoch (a key colleague) both worked for him. Franklin, introduced by Michell, was a hero to him (they took to each other enthusiastically). Banks and Herschel were friends (Boulton supplied Banks with green glass earrings to barter on Cook’s voyage), Boswell and Johnson were suitably-impressed visitors.
Edison was an early customer of Eastman’s — their inventions were mutually complementary — and cooperated with him over a long period. Baekeland sold his photographic-paper invention to him for thirty times what he’d thought reasonable. Pathé had met Eastman early in the century, and made contact again in the 1920’s to merge their firms. Barnard briefly worked with Eastman (who was adept at employing the right people); Frances Benjamin Johnston had her first camera sent to her by Eastman, a family friend, and acted as his business agent in Washington, but it is unclear what kind of contact they enjoyed.
Siemens corresponded with Wheatstone about electromagnetic issues, and together they invented a self-excited generator. He spent two days showing Faraday around his revolutionary gas furnace in Birmingham, but when Faraday gave his lecture about it he accidentally burned his notes (Siemens later named a cable-laying ship after Faraday). Werner von Siemens was his brother and fellow engineer.
Clementi spent much of his life in England, though it was in Vienna that he had a musical ‘duel’ with Mozart. Cramer, Meyerbeer, Hummel, Berger and Moscheles were among his pupils, as was Field, who effectively became his assistant. Haydn’s visits to London provided public competition but led to genuine friendship. Ever the businessman, Clementi persuaded Beethoven to let him become his British publisher. Moscheles, who had studied with him in London, was one of the pallbearers at his funeral.
After a career in theatrical spectacle (he was responsible for the Paris and London dioramas, and had been a scene-painter for the Paris Opera), Daguerre joined with Niépce to develop the first permanent form of photography. Morse, who met Daguerre in Paris, may or may not have taken the process back with him, but was one of the first to make daguerrotypes in North America. Arago got government funding for Daguerre and Niépce’s work thus allowing the technique to be made public, though the latter had by then died.