Tait was a schoolfriend, in fact a friend for life. At 23, Maxwell famously provided the mathematical theorisation of Faraday’s more empirically-based electromagnetic work (though it overshadows all else, this was far from his only significant achievement). Thomson and Stokes were friends and mathematical-physics colleagues. He corresponded with Wheatstone on telegraphy, sent Gibbs a plaster model after reading his paper on the 3D representation of thermodynamics, and was a friend of Babbage’s. Airy also corresponded; he described a paper of Maxwell’s as “one of the most remarkable applications of mathematics to physics” he’d ever seen.