Why the first laboratory self-exciting dynamo was at Newcastle

This article describes how a succession of events starting in 1946 led to the world's first laboratory self-exciting simply-connected dynamo in 1963. In Manchester, in l947, an interest in the magnetic deflection of cosmic rays and Babcock's measurement of the magnetic field of a remote star, led Blackett to resurrect the idea of a “fundamental rotation theory” for the production of the Earth's magnetic field. Bullard suggested a geophysical test of the theory – measure the variation of magnetic field with depth inside the Earth. Blackett gave the job of doing this to a newly arrived Junior Lecturer, Runcorn. As the mine work was coming to an end, in 1949 Runcorn took on a Ph.D. student, Lowes, and started him off on a project based on a 1948 suggestion by Bullard that an individual non-dipole field focus could be produced by electromagnetic induction in a rotating eddy in the Earth's conducting fluid core. When Bullard produced his paper, to allow him to get an algebraic solution, he had to assume that h...