Méchain and Delambre were together charged with measuring the length of the meridian from Dunkerque via Paris to Barcelona, in order to fix the precise length of the metre. Working separately over a decade, Delambre kept the more secretive Méchain informed of his results, and eventually helped his struggling colleague to complete his task. Delambre taught Comte, minded Thompson, and arranged for publication of Fourier’s work on heat-conduction. He corresponded with Gauss and Maskelyne, enjoyed warm friendly relations with Laplace, attended Ampère’s ill-conceived wedding, and helped him to a job.
Duhem published ground-breaking work in the history of science, made a substantial contribution to the philosophy of science, and did important work in mathematical physics. Hadamard was met as a student and remained a firm friend. Poincaré examined Duhem’s doctoral thesis (after his first one had been rejected — Duhem’s own talent for making enemies was outmatched by Berthelot’s shameful obstruction of his career), and remained a respectful colleague and correspondent. Mach was a significant correspondent and influence; Perrin looked up to Duhem, Curie disagreed with him about Maxwell, and Pasteur ignored him.
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.
Alain (Émile Chartier) taught him; Sartre, Nizan and Aron were fellow-students. Cavaillès encouraged him to join the resistance during WWII. Bachelard taught alongside him. Deleuze and Bourdieu studied under him; he sponsored Foucault’s doctoral thesis on the history of madness, and advised Derrida to establish himself seriously before indulging in intellectual humour. Althusser declared that his debt to Canguilhem was incalculable.