Oldest and largest English-language general encyclopaedia.
Its three-volume first edition was published in 1768–71 in Edinburgh, Scot. In subsequent editions it grew in size and reputation. The most famous editions include the ninth (1875–89), known as "the scholar's encyclopaedia," and the 11th (1910–11), which, with contributions from more than 1,500 experts of world reputation, was also the first to divide the traditionally lengthy treatises into more particularized articles. The current edition, the 15th (1974, with a major revision in 1985), embodied a new structure, dividing the major articles from the shorter ones. Encyclopædia Britannica now also appears in CD-ROM and on-line versions. A series of ownership changes led to its purchase by American publishers in 1901; since the 1940s it has been published in Chicago.