ARTILLERY 



cussed. The subject appears very fairly put by Major C. H. Owen, Professor of 

 Artillery, at Woolwich. Ho says: 'Various opinions are hold as to the relative 

 advantages of breech- and muzzle-loading ordnance, but the latter would appear to bo 

 t'he best adapted to general service, as they are stronger for equal weight^ of metal 

 and simpler in construction. The advantages of loading cannon at the breech :\rc, 

 that a projectile of larger diameter than tho bore can bo used t and its axis will con- 

 sequently be stable ; that tho gun can be loaded when run-up, tho gunners being 

 therefore less exposed ; that the gun can bo worked in a smaller space (than a M. L.' 

 piece) ; the clearing of the boro can bo more readily effected, and any ignited sub- 

 stance leftin the bore can bo seen and removed; also there is no danger of the shot not 

 being luyine. This plan, however, is attended with tho following disadvantages, viz. 

 that tho construction is more complicated than that of a muzzle-loading piece ; that 

 if tho gun bo of largo calibre, the brooch-loading apparatus, when sufficiently strong 

 and heavy, will bo unwieldy ; and that with tho same weight of metal, tho brooch -' 

 loading is a weaker and less enduring construction than tho muzzle-loading. On tho 

 other hand, a muzzle-loading gun has a simpler and stronger construction, but tho gun 

 detachments are more exposed than with a breech-loading gun, and if loaded carelessly, 

 the shot may not bo rammed home, in which case the metal of tho gun may be fractured 

 by tho suddenly condensed gas.' 



On tho Systems of Kifling, Major Owen, K. A., one of our best authorities, writes : 

 'In what does a system of rifling consist? Essentially in the method of giving 

 the rotatory motion to the projectile. This definition will not satisfy some inventors, 

 who wish to claim a particular twist as a part of their system of rifling. It would, 

 however, be quite as reasonable to claim a particular charge. Tho rotatory motion, 

 as you all know, is given to prevent the projectile from turning over in flight ; and 

 tho velocity of rotation required depends upon the form, length, and weight of tho 

 projectile, no matter what the system of rifling may be ; in fact, tho number of re- 

 initial velocity -, , - . 

 volutions made by a shot =, . ~ . . ., and therefore, with the same charge, tho 



samo twist must bo obviously necessary. 1 



' A twist, like a charge, may suit a particular rifled gun, but this is quite another 

 thing, A gaining twist is advantageous, for, by employing it, the initial strain upon tho 

 gun is reduced, the rotatory motion not being given when the shot is set in motion, but 

 gradually acquired as it moves down the bore. It is better to give rather more twist 

 than is required under ordinary circumstances at the expense of a little extra 1 strain ; 

 for should the twist be merely sufficient to impart tho necessary rotatory motion with 

 -the service-charge, the velocity of rotation will probably be too low with a reduced 

 charge to keep tho projectile steady in flight.' 2 



The diameter of the bore has also been often mixed up with the system of rifling, 

 with which it can have nothing whatever to do. As the diameter is decreased, so 

 will tho elongated projectile oppose a less surface (in proportion to its weight) to tho 

 resistance of tho air, or that of tho substance fired at ; but, on the other hand, it will 

 expose a loss area to the force of the gas, and will therefore have a lower initial 

 velocity ; it will have less capacity as a shell ; its cartridge must be elongated, thereby 

 throwing the strain forward ; the amount of powder that can bo usefully employed 

 will be less ; and if the length of the bore bo not increased, the expansion of the gas 

 will be moro limited. -This question has boon discussed, and should be thoroughly 

 understood. In the Table below the loss of initial velocity by decrease in the size of 

 tho bore is clearly shown : 



' The Initial Velocity is very littlo affected by the system of rifling. 



" This was particularly shown by flic inaccurate practice of the 600- pounder, when fired with a 

 small charge. . . - 



