Mr Hadow, who was the first person to trek solo to the North Pole, said the knickers were kindly donated by a supporter of the expedition.
Speaking from the Arctic via satellite phone, he said: “It an entirely genuine situation. If you can get gossamer thin material and attach it your ski pole it is particularly useful for this project because we can cannot use the compass as we are so close to magnetic north and it is too cold to use the GPS.
The two portraits show the same person, "Mrs Bennett", before and after treatment. The one on the left is inscribed "Mrs Bennett. Disease from 1818 to 1821", and shows Mrs Bennett in a lace cap and night-gown, afflicted with a skin disease (or a skin manifestation of systemic disease) covering most of her face and parts of her neck and chest.