Within a few years a web of magnetic stations laced the globe: at St Petersburg, Beijing and Alaska, Canada and Jamaica, Australia and New Zealand, Sri Lanka and even the remote island of St Helena in the South Atlantic where Napoleon had been incarcerated. Almost two million observations would be taken in three years. Like today’s climate change scientists, those who worked at these new stations were collecting global data, participating in what we would now call a Big Science Project. This was an international collaboration on a vast scale – the so-called ‘Magnetic Crusade’.
