The great mass of officers on duty at the Academy are, of course, the instructors. These men are all officers of the Army, graduates of the Academy, who are detailed for duty in the various departments. Formerly, the tour of duty was for four years, but since the passage of a law by Congress, the Detached Service Law, familiarly called the “Manchu Law,” the time that an instructor can remain on duty at West Point, is dependent upon the amount of duty that he has had with troops during the preceding six years. No officer can remain on detached service, such as that at West Point, for more than four years. It is apparent, therefore, that the corps of instructors is constantly changing, resulting in the introduction into the work of new blood and fresh viewpoints. This changing of instructors maintains a high standard of enthusiasm for teaching, so often lacking in institutions of learning where a subordinate teacher goes over, year in and year out, the same ground. Moreover, the system of officer instructors is employed on account of the disciplinary value of their presence over the cadets. West Point is first and foremost a Military Academy, and it is of primary importance that the cadets shall absorb by example the spirit of discipline, and military deportment. Not the least of the advantages of having officers teach cadets is the contact that their presence maintains between West Point and the Army. Officers are selected for duty at the Academy by the Heads of Departments who make every effort to secure men especially qualified for the work. For example, the instructors in the Department of Engineering are all Engineer officers; in Ordnance and Gunnery, mostly Ordnance officers; in Chemistry and Electricity, usually Coast Artillery officers; in Mathematics, officers of the staff and line who excelled in this study as cadets; in English and History, line officers with recognized literary tendencies; in Languages, officers whose advantages have enabled them to acquire a good speaking knowledge of either French or Spanish. Until the outbreak of the European War, officers on duty in the Department of Languages were ordered to spend the summer in study in either France or Spain. They thereby were able to perfect their knowledge to an extent that rendered them most efficient instructors. Detailed to this Department are two native Spaniards and two Frenchmen, whose services are employed to carry along the instruction of the officer instructors as well as that of the cadets, so that every opportunity is offered to the cadet to progress as far as his ability will permit him in the time allotted these studies.