Fen, a place overflowed with water, or abounding with bogs.— See Bog and Draining.

The most extensive fens in this island, are those of Lincolnshire, which afford considerable advantages to the inhabitants, who take large quantities of fish, and wild fowl; the latter are even sent to the London markets.

Fens generally abound with saline plants, which are very nourishing to cattle, and exceedingly fattening to sheep and horses. Oats will also thrive well in several fen districts; and, in prosperous seasons, yield abundant crops.

Coleseed is likewise cultivated to a very considerable extent on the fens, which indeed might be made more fertne, if the practice of paring and burning them, to the depth of an inch and a half, were more generally adopted.

Several acts of parliament have been passed for draining the fens, chiefly in the counties of Kent, Cambridge, and Lincoln ; and by 2 Geo. II. c. 34 and 39, commissioners are appointed, for the effectually draining and preserving of fens in the isle of Ely ; who are empowered to construct drains, dams, and other works ; they are likewise authorized to make an assessment on the land-holders, whose lands, in default of payment, are liable to be sold.

Fen, the name of a very pernicious disorder, to which hops are subject. It consists of a kind of moss, or mould, which grows rapidly, and does considerable injury to the hop-grounds, unless it be eradicated immediately on its first appearance.