Page:The New International Encyclopædia 1st ed. v. 09.djvu/424

* GUNNERY. 374 GUNNERY. one or two guns, the broadside battery is generally available in any direction from 45 or 50 ileyrees forward of the beam to a point at an eijual angle abaft it. The advantage of giving the widest practicable arcs of fire (the angle through which the gun can be trained or fired) is easily seen, for it may result in giving a deci- sive advantage, and it is carefully sought when the plans of a ship are made. It was formerly the custom to fire at the enemy's water-line, be- cause hits there were most serious, and if the shell fell short it would usually strike the ship after making a 'ricochet' (i.e. glancing from the surface) ; while if it went too high it might cause no damage whatever. The ricochet of spherical projectiles was visvially in the line of fire : but elongated rifled projectiles do not con- tinue on the course after striking the water: they usually turn to the right, often at a considerable angle, and sometimes shoot sharply upward to a considerable height. The present practice is therefore to aim at the middle of the target the enemy presents, both as regards length and height. In defen.se against torpedo boats, the smaller guns of ships are chiefly relied upon : but as a result of experiment and experience in war it is found that the very small pieces are of little use. They are inaccurate, owing to the curved path of the projectile, which loses its velocity more rapidly than a large one. while it is too small to disable a modern torpedo boat. Guns using projectiles weighing from 6 to 14 pounds are the ones chiefly relied upon ; but it is doubt- ful if even these are quite adequate, and it is certain that shrapnel from 5-inch. 6-inch, 7-inch, and 8-inch would be very useful. The last point to consider about a gun is speed of fire. As has already been said, speed is last to be considered, not because of lack of impor- tance, but because a gun must be safe, and its fire accurate and destructive, or speed is useless. A high rate of fire can be attained only by means of a properly designed mount and breech mech- anism, adequate ammunition supply, a reason- ably steady gun-platform, and a well-trained crew. The mount nuist be strong, and admit of rapid and ea.sy training and elevation. The breeeh mechanism must be simple, effective, strong, and quick working. Xo delay must occur through inadequacy of the amnumition supply, and there must be sufficient room for the crew to carry on the operations of loading in the most expeditious manner. The speed of fire from tur- rets is generally nnicli reduced for lack of room, particularly in turrets mounting guns of 8-inch calibre or less. More, perhaps', depends upon a suitable form of drill than upon anything else. Exact adherence to prescribed forms should not be required ; a drill manual should be a general guide, and not a plan to which exact compliance is required, if it can be shown that greater speed can be obtained by a variation of it. In prepar- ing a plan of drill, the fact must be kept in view that the greatest efTeetive speed is attained when the work is so divided that every man is working all the time in a manner which will not interfere with, but facilitate, the work of others; and no man should be called upon to do what another can do better, if that can be avoided. Such a division of duty is usually impossible ; but it is the end to be soiight and approximated to. Or- ders and all talking should he done away with, and the different operations going on at the same time made "to fit in with each other in a way to make orders superfluous. Having by experiment developed the best drill, so far as the oflieer in charge of it is able to jvidge, the men should be exercised at their duties until their movements have become nearly me- chanical. The stage is now reached at which target practice must be begun. In the United States Navy the gun-firers for the principal guns nearly all receive a preliminary training in the gunnery ships, and hold the ratings of gun cap- tain (chief, or first or second class). In the United States service tlie expenditure of time and amnumition for target practice is greater than in any foreign navy. There are seven prac- tices a year in which full-calibre ammunition is used ; six sea practices in which no attempt is made to obtain an exact record of the firing be- yond what is necessary for purposes of immediate instruction and the information of the gun-firer, so that he can correct hi^ errors; and one record practice in which the exact records of the firing are sought, in order to furnish the Navy Depart- ment with information as to the efficiency of the men who operate the guns. The expenditure of ammunition per gim per year is fixed as follows: 10, 12. and 13 inch guns", 12 rounds: 8 inch, 18 roimds: 7-inch, none yet in service; 4. 4.7, 5, and (> inch gims. 24 rounds; 3 inch. 36 rounds; 3-inch field gim. 18 rounds; 1, 3, and 6 pounders, 72 rounds: Catlings and Colt automatic guns, 1 100 rounds. In order to give a greater amount of practice tluin is afi'orded by any reasonable exjienditure of tlie ordinary ammunition, the sub- calibre principle is used. Tliis consists of a small barrel or gim securely clamped to the outside of a large gun, or inserted in disks and then placed in the inside of the gun. where it is firmly held in position. The gun-firer trains and ele- vates the large gun. using its sights, but setting the elevation in accordance with a table which adapts them to the various ranges of the small piece. So far as the training of the gun-firer is concerned, this is almost as good as firing large charges, and the reduction in expense is 00 to 99 per cent. The sub-calibre practices are held about once a month, and the amount of ammunition which may be expended is left to the discretion of the commanding officer of the ship. The targets used are made of canvas, supported by a frame- work or ]xile : the common one. supported by a pole, is triangular: but a rectangular one will probably be used in future for certain record practices. In addition to target practice, gun- firers are practiced at aiming with a device which records the direction of the sights when the firing button is pressed, and which keeps the little tar- get, which is at the muzzle of the gim, in motion in a manner to simulate the apparent movement of a real target past the sights when the ship rolls. For training on shore, an oscillating or rolling platform has been designed which gives the gun motion similar to that which it has on a rolling ship. For further information on the subject, con- sult: Glennon. Accurari/ and Frobahility of Fire (Baltimore. 1888) : id..' Inferior Bnllistic^ (Bal- timore. 1894) ; Insrersoll. Tcxf-Iiook of Ordnance and Gunneni (Annapolis. 1899) : id.. Exterior JialUstics (Baltimore. 1893 H Brufl?. Text-Iiook of Ordnance and Giinnert/ (New York. 1896) : Proceedinfis of Vnited Sltatcs Xaral Inxtifute (Annapolis, current) ; Journal of the United