Abstract

Magnetic observations were essential for polar navigation, and were carried out systematically on both sea and land-based expeditions to the Canadian Arctic throughout the nineteenth century. John Franklin took a particular interest in magnetic studies and encouraged the Admiralty to adopt Robert Were Fox's dip circle. The establishment of the Toronto magnetic observatory provided a base for John Henry Lefroy's survey of the North West Territories. The Royal Navy's programme of magnetic research, commenced in the aftermath of the Napoleonic Wars, was maintained until the British Arctic Expedition of 1875–76, commanded by Nares. In all these expeditions, the nature and limits of the observations were determined by the available instruments