Samuel Engel (1702-1784) was a Swiss geographer, agronomist, and mathematician active in the middle part of the 17th century. His main work, Memoires and Observations was published in 1765 and while somewhat obscure today was highly influential in the 1700s. Engel argued that ice only formed in fresh water and that, such being the case, the Arctic Ocean would be ice-free and navigable closer to the poles. Engel's theories influenced exploration in search of the Northwest Passage, specifically, the launching of the disastrous 1773 Phipps expedition to the North Pole. He also wrote several articles for Diderot's Encyclopedie, including a description of a pre-Columbian Chinese colony in North America - Fusang. Engle also argued that Baron Lahonton, an enigmatic explorer of America's inland waterways, was in fact fictitious - though he nonetheless incorporated Lahonton's geography in his own maps.