FIELD (a word common to many West German languages, cf. Ger. Feld, Dutch veld, possibly cognate with O. E. folde, the earth, and ultimately with root of the Gr. πλατός, broad), open country as opposed to woodland or to the town, and particularly land for cultivation divided up into separate portions by hedges, banks, stone walls, &c.; also used in combination with words denoting the crop grown on such a portion of land, such as corn-field, turnip-field, &c. The word is similarly applied to a region with particular reference to its products, as oil-field, gold-field, &c. For the “open” or “common field” system of agriculture in village communities see Commons. Generally with a reference to their “wild” as opposed to their “domestic” nature “field” is applied to many animals, such as the “field-mouse.” There are many applications of the word; thus from the use of the term for the place where a battle is fought, and widely of the whole theatre of war, come such phrases as to “take the field” for the opening of a campaign, “in the field” of troops that are engaged in the operations of a campaign. It is frequently used figuratively in this sense, of the subject matter of a controversy, and also appears in military usage, in field-fortification, field-day and the like. A “field-officer” is one who ranks above a captain and below a general (see Officers); a field marshal is the highest rank of general officer in the British and many European armies (see Marshal). “Field” is used in many games, partly with the idea of an enclosed space, partly with the idea of the ground of military operations, for the ground in which such games as cricket, football, baseball and the like are played. Hence it is applied to those players in cricket and baseball who are not “in,” and “to field” is to perform the functions of such a player—to stop or catch the ball played by the “in” side. “The field” is used in hunting, &c., for those taking part in the sport, and in racing for all the horses entered for a race, and, in such expressions as “to back the field,” is confined to all the horses with the exception of the “favourite.” A common application of the word is to a surface, more or less wide, as of the sky or sea, or of such physical phenomena as ice or snow, and particularly of the ground, of a special “tincture,” on which armorial bearings are displayed (see Heraldry); it is thus used also of the “ground” of a flag, thus the white ensign of the British navy has a red St George’s cross on a white “field.” In scientific usage the word is also used of the sphere of observation or of operations, and has come to be almost equivalent to a department of knowledge. In physics, a particular application is that to the area which is influenced by some agent, as in the magnetic or electric field. The field of observation or view is the area within which objects can be seen through any optical instrument at any one position. A “field-glass” is the name given to a binocular glass used in the field (see Binocular Instrument); the older form of field-glass was a small achromatic telescope with joints. This terms is also applied, in an astronomical telescope or compound microscope, to that one of the two lenses of the “eye-piece” which is next to the object-glass; the other is called the “eye-glass.”