the garrison should have time to prepare for action. Moreover, it should be remembered that the thorough mopping up of such an underground system is the more difficult the farther the assailant is from his base of supply. This last condition is not so important as the first three; a case is known where the Germans successfully defended an underground system which was close to our jumping-off trench. III. From the foregoing it will appear that new organizations should have the following characteristics: 1. All of the essential elements of the defensive works should be invisible and outside of the visible trench system of the position. This can be achieved by the creation of "islands of resistance" with underground communications placed at such distance from the trenches as to escape damage during the artillery preparation (about 60m.). (a) Arrangement. As a matter of principle, the machine guns are disposed to provide a flanking fire. The other elements of the defense afford protection to the machine gun personnel against direct attack. The several specialists, hand and rifle grenadiers, and machine riflemen, being well supplied with ammunition, give a considerable power of resistance for a small effective force. The emplacements of these specialists are connected by underground galleries with those of the machine guns. The attached sketches give examples of the dispositions proposed. They include a certain number of underground shelters (for personnel, command posts and stations supplies, munitions and anti-gas chambers) insuring to the garrison, in addition to protection against a heavy bombardment, the power of making a prolonged defense. The ascending galleries, ending openings of low relief, allow the machine gunners and other specialists to reach their fighting posts promptly. The openings are generally in shell-holes or are made to resemble shell-holes and they should be carefully camouflaged. (b) Exits. The underground system is reached by several galleries connecting with the neighboring fire or communicating trenches. In addition one or two other galleries are brought to the surface in the open in rear, to permit of immediate counter-attack in case of the (c) Observation Posts. The "island of resista (d) Execution. The construction of th In a great number of cases (on counter-slopes, But as a rule advantage will be taken of the numerous communicating trenches on a position from which galleries will be driven to the site of the underground system, after which the several communicating galleries to the emplacements of the various specialists will be dug. On account of the amount of work required by such organizations, it will not be possible to undertake at once all of the "islands of resistance" required for a given position. Those should be provided first which assist in the defense of the key points. "Islands of resistance" may be constructed as a whole or progressively. In the latter case, emplacements for the machine guns will first be provided in shell-holes with underground shelters for the men. The scheme will then be carried out by the installation of posts for grenadiers, rifle grenadiers, machine riflemen, riflemen and ob servers. Whatever order of construction is followed, the work should be carried on by companies of engineers, assisted by machine gun companies, and they should be provided with mining machinery to hasten the work. 2. It would be desirable to entirely conceal all parapets, but this is impossible. A command post, a shelter, an observing post may be concealed, but it is not possible to conceal the whole position. Recourse must be had to dummy works. The most useful measures are |