Ascension Island, an island about 8 m. in length and 6 in width, lying in the south Atlantic ocean, in lat. 7° 56' S., Ion. 14° 25' W. It is of volcanic formation, mountainous, and was barren and uninhabited until the imprisonment of Napoleon at St. Helena, when it was occupied by a small British force, who have continued to cultivate and improve it. Its shores supply a vast number of turtles. It serves as a depot and watering place for ships.