4to. (Title-page slightly soiled and with neat repair, some light spotting.) Modern half black calf, marbled boards. FIRST EDITION. Rye arrived in the Canary Islands in April 1791 aboard the H.M.S. Gorgon, where he decided to attempt to scale Pico de Teide, the highest mountain on Teneriffe. Rye's may be the first published account of an ascent of the 12,198 ft. peak; his measurement of the exact altitude of Pico de Teide was an important aid to navigation, as the islands featured prominently in sailing directions. Not in Perret. RARE: only two other copies have appeared at auction according to online databases.