1-158-390 - Oxford Science Archive/Heritage Images

Aurora Borealis or Northern Lights observed from northern Norway, 10 October 1868, (1906). Aurorae are caused by the interaction of the particles in the solar wind with the Earth's magnetic field. The phenomenon is most visible in polar regions but in times of intense solar activity can be seen at lower latitudes as well. From Elementary Treatise on Physics by A Ganot. (London, 1906).