Attacks on hill positions show that there is a range at which the greatest efficacy may be obtained from fire directed against the top of the height itself. This maximum efficacy gradually dwindles as the position is approached. This fact has led the Swiss to retain a _Main Firing Position_. (See Figure, p. 182. Fire effect from A and from B). For the purpose of determining the favorable range, “D,” corresponding to a certain height (of the enemy’s position) “H,” Lieutenant-General ROHNE has deduced the following formula for rifle model ’88:[172] D = 15.H + 500. [172] Capitaine CUGNAC, D = 14 (H + 50). See also the work of Captain KNOBLOCH, _Zur Technik des Feuerangriffs gegen Höhenstellungen_, _Swiss Monthly Journal_, 1907. The well-known plateau of the “Galgenhügel” at Wörth, which is at present crowned by the monument of the 50th Infantry (elevation 35 m.) could be effectively swept by the fire of our present-day weapons at 1025 m.; a further advance would reduce the fire effect. For rifle model ’98 the formula might be stated: 20. H + 600. It is only in fortress warfare that it might occasionally be possible to apply this formula. To determine at what distance the defender must take position in rear of a crest, in order to sweep the slope facing the enemy with his fire (aiming points being resorted to) without being himself exposed to view, is of still less value for use in the field. According to General Warnet of the French Army, if “p” is the degree of slope expressed in centimeters, the defender should choose between two points which lie between (p + 5) 1000 and (p + 3) 1000. When the degree of slope is 1 cm. in 10 cm., the defender should take up his position either 600 or 300 m. in rear of the main crest. In such a position the defender will, it is true, be protected to a certain extent from the enemy’s fire, but can only very inadequately defend the slope facing the enemy. A concentration of fire on certain targets is impossible and the attacker is given an opportunity to reach the crest, here and there, without coming under fire. Thus ballistic advantages must be given up in the face of the numerous tactical disadvantages. We have mentioned this subject here, to show the strange excrescenses which an undeniably sound basic principle may develop in the hands of theorists, who have entirely forgotten that in war only that which is simple succeeds. “Indirect Rifle Fire” is to be used in firing on a target not visible from the firing position. In this connection, the following is taken from the report of Captain KNOBLOCH, Austrian Army,[173] on _Schieszaufgaben unter feldmäszigen Verhältnissen_: