| Description | Graphical representation of horizontal force magnetometer readings taken at hourly intervals, 5-7 April 1843, curve plotted against Singapore mean time [top] and Gottingen mean solar time [bottom].
Headed [p.1]: 'Curve representing the Hourly changes of Horizontal Force during the three days of great disturbance 5th, 6th, & 7th of April 1843'. The printed sheet is inscribed 'Wm. H. Allen & Co. London'. |