Réaumur was a scientist of unbounded curiosity, many of whose investigations and discoveries show a mind ahead of its time. He was taught by Varignon, dined regularly with Buffon, put a geometric problem concerning honeycombs to his friend König, produced the first systematic study of insect life, and prompted Jussieu to show that corals were animals not plants. He taught Bonnet, Trembley, Spallanzani and Guettard, researched electricity with his younger colleague Nollet, and was assisted by Pitot. Musschenbroek wrote to him about his Leyden-jar experiments; Haller and Morgagni also corresponded.
Lomonosov was one of Russia’s greatest scientists, though in his time was mainly known as a writer: a true polymath, he published work in physics, chemistry, geology, astronomy, classics, language and history, largely working alone. Wolff influentially taught him in Germany. He became Euler’s assistant and later his close colleague in St Petersburg; they corresponded until Lomonosov’s death. He stood as guarantor for his friend and colleague Gmelin, who defaulted (Euler intervened, Gmelin paid him back). He warmly supported Müller’s explorations in Siberia, but (both were hot-headed) took violently against his theory of a Norse origin for the Russian nation.
Talbot (or Fox Talbot – both are used, though Talbot is correct), one of the great founders of photography, was also a noted mathematician, astronomer, botanist and more. His two great lifelong friends and colleagues were John Herschel and Brewster; Herschel’s chemical knowledge and terminological wisdom were critical, while Brewster’s interest in light and optics closely paralleled Talbot’s own. Talbot worked with Arago at his Paris observatory, ordered optics from Fraunhofer, and swapped seeds with Hooker. He corresponded with Crelle about calculus, Hincks about cuneiform translation and Zach about astronomy, among many others.
Humboldt, a small man and intellectual giant, was uncommonly well-connected. Werner taught him geology. Gay-Lussac savaged some of his work, but they became friends and ascended Vesuvius in eruption. He named the brazil-nut tree after Berthollet, travelled in the Low Countries and England with Forster, explored Latin America with Bonpland, and met Jefferson. Felix Mendelssohn, a family friend, dedicated a cantata to him. He wrote to Arago, starting 40 years’ friendship; Faraday was another correspondent. He knew Heine and Darwin, met Meyerbeer frequently, contributed to Schiller’s periodical, and taught Agassiz geology.
Small influentially taught Jefferson. Franklin, a great friend both before and after, spent nine months together with him in Paris. Jefferson sent Buffon, whom he’d visited in Paris, the rather worn skin and bones of a moose so he could have it stuffed (Buffon argued for the superiority of old-world species). Humboldt was a dear friend, spending several weeks with Jefferson, while Paine walked arm-in-arm with him on Washington streets. Paine and Priestley (both close friends) and Peale and Rittenhouse were important members of his literary and intellectual circle. Condorcet was among his other correspondents.
Whewell met Owen at school, and Babbage, Herschel and Peacock at Cambridge. He did an experiment with Airy, sailed with Wordsworth, and visited Ely Cathedral with Ruskin. He taught de Morgan, Thackeray and Tennyson, knew Roget and Talbot, and was a close academic colleague of Sedgwick and Lyell. Widely consulted, Whewell originated still-current scientific terminology with Lyell and with Faraday, and famously rose to Coleridge’s challenge by coining the word ‘scientist’. Jones was a close friend. Despite a famous debate with John Stuart Mill, they never met. Herschel praised the unparalleled breadth and depth of Whewell’s learning.
Babbage and John Herschel became friends as students, and stayed close colleagues for life. With Peacock and Whewell they started a society at Cambridge to counter the poor maths teaching there. Babbage discussed geothermal ideas with Lyell, map-making with Humboldt (who invited Gauss to meet Babbage over breakfast), wrote to Davy about a calculating engine, and influenced both Darwin and Mill. Among his huge circle of friends and correspondents were Dickens, Stowe, Ruskin and Mendelssohn; Cameron, Martineau and Somerville; Nasmyth, Brunel, Boole and de Morgan; and scientists from Ampère to Le Verrier.