Encyclopædia Britannica
The articles in the Britannica are for educated adults, not for children, and written by about 100 full-time editors and over 4,000 expert contributors. The Britannica is the oldest English-language encyclopædia now. It was first published between 1768 and 1771 in Edinburgh, Scotland and grew very popular, with its third edition in 1801 comprising of 21 books.