5. Points of Military Importance.—In addition to the description-points, when there is time, any points in the field of fire which are of military importance—such as a road, a bridge ([Fig. 50]), or the forward edge of dead ground—at which fire may suddenly have to be directed, should also be named and indicated to fire-unit commanders. This should be done, if possible, whenever such points are difficult to describe and cannot be indicated quickly.
6. Rules for describing Targets.—(i) Targets must be indicated by short, accurate, clearly understood, descriptions of their nature, features, and exact position.
(ii) Field-glasses may be used to discern targets before indicating them. But aiming-points must always be described as they are seen with the naked eye, and not as seen through field-glasses, otherwise the men, being without glasses, may fail to recognize them.
(iii) In both attack and defence the front should always be pointed out, so that if a general direction, such as half right, is used to indicate a target, men will look in the proper direction with regard to the front. This is necessary, because the formation of the ground, the line of cover, and the siting of trenches does not always permit of men facing directly to the front.
(iv) As a general rule the finger-breadth and clock-face methods of describing targets will only be used when they will shorten and simplify the description, as well as make it more accurate.
(v) Only one system of indicating targets should be employed in a battalion, and, if possible, in an army, so that the men may recognize targets described by commanders of other fire-units should they become separated from their own in action.
(vi) When possible, targets will always be described and their range given before the occasion for firing arises, so that men may adjust their sights and be ready to open fire without further orders as soon as the target appears.
7. Finger-Breadth Method ([Fig. 49]).—(i) This method may be employed to indicate roughly the approximate distance of an objective from a description-point. Only one hand should be used, even if more than one hand’s breadth is required to indicate the distance. The arm must be held out perfectly straight from the shoulder in front of the face, with the fingers vertical. If, however, the object is immediately above or below the description-point, the fingers should be horizontal. In measuring distances, one eye should be closed, and both the description-point and the objective kept in view.
(ii) Instruction in the Finger-Breadth Method.—Results obtained by this method are necessarily inaccurate, because the hands and fingers vary in size and in distance from the eye with each individual. It is, however, a useful guide for measuring approximate distances. After the first few lessons in the use of this method, measurements should first be judged, and then the fingers should be used to check them. It will be found that when men have been thoroughly trained in this method they will seldom have to use their fingers for measurements at all except in very doubtful cases.
