Beyond 600 m., an error in the range exerts a greater influence upon the efficacy of fire than does the marksmanship of the skirmishers.[1] When an improper elevation has been selected, the efficacy of the fire decreases as the compactness of the "cone of dispersion" increases; in other words, the efficacy of the fire decreases as the excellence of the marksmanship of the men and their coolness in the face of the enemy increase. (See pp. 170 and 171, infra).
The following expedients for ascertaining ranges may be mentioned:
(a) Pacing and galloping;
(b) Estimating distances on the ground by eye (by comparison with known distances; by estimating part of the distance);
(c) Firing trial volleys (ranging);
(d) Taking the range from a map of large scale or obtaining it directly from infantry or artillery already engaged;
(e) Measuring the range directly on the ground.
Pacing (employed in Russia, France, and Austria) gives inaccurate
results. There is a difference between the number of paces a man takes
per 100 m., on a chaussee and in a ploughed field. Length of pace depends
upon the character and slope of the ground.[2] In pacing over varied
ground, a man follows the slope line while the projectile follows an airline.
Therefore it would seem that pacing is only practicable at short
ranges when the enemy is not near. The same is true of galloping over
the distance. (The length of a horse's jump at a gallop is on an average
3 m.).
In estimates made by individual men, the error amounts
- ↑ Rohne, Das Gefechtsmäszige Abteilungsschieszen der Infanterie, p. 13.
- ↑ Professor Rziha ascertained the following diminution of the length of a
pace at different degrees of slope:
Descending slope, degrees. 0 5 10 15 20 25 30
Length of pace in cm. 77 70 62 56 50 45 30
Number of paces per 100 m. 129 143 161 179 200 222 333
Ascending slope, degrees. 0 5 10 15 20 25 30
Length of pace in cm. 77 74 72 70 67 60 50
Number of paces per 100 m. 120 135 138 143 148 166 200According to Major Czerny, Austrian Army (Treffwahrscheinlichkeit, in Streffleur, 1906, II), the error may be as much as 16 per cent of the range.
