Letter from Chr [Christopher] Hansteen, Observatory at Christiania, to [Colonel Edward Sabine, Foreign Secretary of the Royal Society] Presenting his calculations on a number of observations of the magnetical inclination across Europe. The third and fourth page contain tables showing the inclination of the magnetic needle in various locations across the world. [Letter published in the 'Proceedings of the Royal Society of London' in vol 6., pp.393-396. See related material.] 6 January 1854