17. Ross, James Clark, Sir (1800-1862) 

“On the Position of the North Magnetic Pole.”  In: Philosophical Transactions of the Royal Society of London, 1834, pp. 47-52.

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Beginning of James Clark Ross’s article on discovering the north magnetic pole, from Philosophical Transactions of the Royal Society of London, 1834.

The principal scientific achievement of John Ross’s Second Voyage was the location of the north magnetic pole by his nephew, James Clark Ross.  Previous voyagers into Lancaster Sound, like Parry, had commented that their compasses became useless in this region, and so it was known that the magnetic pole was somewhere in the area.  Ross ran it down by using a dip circle, a device that measures magnetic variation or dip.  This instrument is essentially a compass tilted on its side, and the closer one gets to the north magnetic pole, the more the needle approaches a vertical position.  At Cape Adelaide, on the west coast of the Boothia Peninsula, Ross measured a dip of 89º 59’, and concluded that the pole was directly underfoot.  He erected a cairn, and a flag, and marked the spot on his maps.  This pole would continue to appear on all arctic maps for decades, until it eventually moved north.

It may seem strange that exploring Arctic regions would have a magnetic aspect, but the British took this very seriously; indeed, a “magnetic crusade” was the principal justification for both Arctic and Antarctic exploration in the 1830s.  As Ross says at the end of his journal article, “The science of magnetism, indeed, is eminently British.”


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