a part of Lower Egypt, included in the space between the branches of the Nile and the Mediterranean Sea. The ancients called it the Isle of Delta, because its triangular form resembled the Greek letter of that name. It extends about a hundred and thirty miles along the coast from Damietta to Alexandria, and seventy on the sides from the place where the Nile begins to divide itself. It is the most fruitful country in all Egypt, but the fertility is chiefly owing to the periodical inundations of the river Nile. The principal towns on the coast are Damietta, Rosetta, and Alexandria. The same name has since been extended to similar alluvial tracts, formed in a similar manner at the mouths of other great rivers.