CHAPTER IX.
ARMY ORGANIZATION—STAFF AND ADMINISTRATIVE CORPS.
By the law of the 12th of December, 1790, on the organization of the public force of France, the Army was defined, "A standing force drawn from the public force, and designed to act against external enemies." [Une force habituelle extraite de la force publique, et destinée essentiellement à agir contre les ennemis du dehors.]
In time of peace, the whole organized military force of the State is intended when we speak of the army; but in time of war this force is broken up into two or more fractions, each of which is called an army. These armies are usually named from the particular duty which may be assigned to them—as, army of invasion, army of occupation, army of observation, army of reserve, &c.; or from the country or direction in which they operate—as, army of the North, of the South, of Mexico, of Canada, of the Rhine, &c.; or from the general who commands it—as, the army of Soult, army of Wellington, army of Blücher, &c.
All modern armies are organized on the same basis. They are made up of a Staff and Administrative departments, and four distinct arms—Infantry, Cavalry, Artillery, and Engineers; each having distinct duties, but all combining to form one and the same military body. In the actual operations of a campaign, these forces are formed into corps d'armée, each corps d'armée being composed of two or more grand-divisions; each grand-division, of two or more brigades; and each brigade, of several companies, squadrons, or batteries.
In speaking of an army in the field, it is sometimes supposed to be divided into two classes of men—the Staff and the line. We here include in the first class—
All officers, of whatever arm, above the rank of colonel;
All officers of the staff corps of whatever grade, and
All officers attached to the staff as aides, &c.;