THE ROYAL ARTILLERY INSTITUTION. 
£7 
** arriver ses coups. Supposons, par exemple, qu’il eftt & tirer sur un lieu apparent, mais 
“ dont 1’eloignement lui fut inconnu, a quoi, 6 due magnanime, lui seryirait en cette 
« £ occasion de savoir que sa pikee sous tel angle porterait a 1,356 pas, sous tel autre a 1,458, et 
<£ sous tel autre encore a 1,574 pas, et ainsi de suite, de degre en degre. A coup sur cela ne lui 
<c servirait a rien, puisque, ignorant la distance, il serait dans rimpossibilite de cboisir 
“ Felevation sous laquelle il devrait tirer sa piece pour atteindre le but propose. II suit de 
“ la que deux choses principales sont necessaires a un artilleur qui tient a tirer d’une mani&re 
<£ rationnelle, et non auhasard, deux choses tellement liees l’une a l’autre, que la connaissance 
<£ de la premiere devient tout a fait inutile sans celle de la seconde (je parle ici de tirs a de 
££ longues distances). La premiere de ces choses consiste a savoir reconnaitre et determiner 
“ approximativement a la vue la distance du lieu qu’il s’agit de battre ; la seconde est de 
” connaitre la grandeur des portees de la piece sous les differents angles d’elevation. ” 
La Balistique de Nicholas Tartaglia, first published in 1537, translated from the Italian 
by Professor Rieffel. Paris, 1845. 
13 We have referred in par. 1 to the necessity for more precise definitions 
of terms than are usually given in English books of Gunnery. Distinctions 
of importance are often lost sight of for want of them, or the same terms 
used loosely to express different things. This applies particularly to the terms 
elevation and range. I have endeavoured in the following to express as 
succinctly as possible what appear to be the principal definitions in rifled 
gunnery, and submit them with all due respect to the judgment of officers 
engaged in instruction. The Erench equivalents are in some cases added. 
Definitions in Gunnery. 
1. Plane op Eire. —The vertical plane passing through the axis of 
the gun. 
2 . Angle op Elevation. — Angle de mire . The angle between the axis 
of the gun and the visual line from the sight on the tangent scale to the 
object. It has no reference to the horizon or to any natural level. 
3. Angle of Inclination. — Angle de tir. The angle which the axis 
of the gun forms with the true horizon, or the angle shewn by a correct 
spirit-level. This is consequently the angle recorded when guns are laid by 
quadrant, 
4. Angle op Departure. — Angle de projection. The actual angle 
which the shot's path on leaving the muzzle makes with the true horizon; 
this when there is windage may differ sensibly from the angle of inclination , 
and appears also to do so in the lighter rifled guns where the shot are 
observed to rise, from the muzzle being slightly thrown up. 
5. Range. —The distance from the muzzle of the gun to the second 
intersection of the trajectory with the line of sight (the first intersection is 
made near the muzzle, where the shot in its ascent crosses the line of sight). 
The range is not accurately the distance to the point at which the shot 
impinges on the plane, unless that is also the point aimed at, but the differ¬ 
ence is practically of importance only at short distances. 
