Men and dogs in an arctic landscape with three hot-air balloons: proposed method of reaching the North Pole by J.P. Cheyne. Coloured wood engraving by C. Roberts.

Licence: Public Domain Mark

Credit: Men and dogs in an arctic landscape with three hot-air balloons: proposed method of reaching the North Pole by J.P. Cheyne. Coloured wood engraving by C. Roberts. Wellcome Collection. Source: Wellcome Collection.