_France._[121] According to the French Field Artillery Regulations (footnote to par. 277), a gun firing time shrapnel covers effectively a front of 25 m., and a battery of four pieces, a front of 100 m. This intensity of fire, which is obtained when each piece fires one shot with proper corrector and range settings (the battery four shots) Aubrat calls “_Density 4_.” When _rafale_ fire (two shots per piece) is employed against a front of 100 m., with proper corrector setting, density 8 is obtained. When the front exceeds 100 m., the deflection of the pieces must be changed between successive shots (_tir avec fauchage_). To obtain density 8 against a front of 150 m., each piece must fire three shots, as prescribed in the regulations. When progressive fire (_tir progressif_) is employed, four different ranges are given, of which only one can be considered effective. When not sweeping, in this fire, each piece fires two shots, thus also obtaining a density of 8. A density of 1 always corresponds, therefore, to one round, fired, with proper corrector and range settings, against a front of 100 m. When a battery (four pieces) fires one salvo against a target having a front of 50 m., density 8 is obtained; by firing two salvos, density 16 is obtained. [121] The following is taken from Lieutenant-General ROHNE’S essay on the work of Squadron Commander AUBRAT, _Les exercices de service en campagne_. The essay mentioned appeared in the December, 1907, number of _Artilleristische Monatsschriften_. The _Commission d’études pratiques du tir_ has made a thorough investigation into the effect produced by shrapnel fire. The following table gives a general idea of the effect to be expected when firing against service targets (_i.e._, the percentage of figures one may expect to hit when employing fire of varying density):