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MODERN GUNS 
 
 AND 
 
 SMOKELESS POWDER. 
 
 ARTHUR RIGG 
 
 JAMES GARVIE. 
 
 LONDON : 
 E. & F. N. SPON, 125, STRAND. 
 
 NEW YORK : 
 SPON & CHAMBERLAIN, 12, CORTLANDT STREET. 
 
 1892. 
 
MODERN GUNS 
 
 AND 
 
 SMOKELESS POWDER. 
 
 PART I. 
 
 INTRODUCTION. 
 
 Gunpowder, the oldest of all explosives, has been 
 the subject of many scientific investigations, sup- 
 ported by innumerable experiments ; but Nature 
 guards her secrets well ; and to this day it cannot 
 be said that the cycle of chemical changes brought 
 about by the combustion of gunpowder is thoroughly 
 understood. 
 
 Its original components vary, but are generally 
 about 75 parts potassium nitrate, 15 parts carbon, 
 and 10 parts sulphur, with other ingredients some- 
 times added. These materials, when simply mixed 
 together, burn with considerable vigour, but cannot 
 rank as an explosive until they have been thoroughly 
 incorporated, so that the different molecules are 
 brought into such close proximity that each finds a 
 neighbour ready and willing to combine on the 
 smallest encouragement. 
 
 Heat furnishes the necessary stimulus, by pro- 
 
2 MODERN GUNS AND SMOKELESS POWDER. 
 
 moting chemical activity ; and, when combined with 
 concussion, the molecules are driven closer to- 
 gether, and this intimate association accelerates 
 their combination. 
 
 The effect of mere concussion is shown to greater 
 advantage when any of the more dangerous ex- 
 plosives, such as iodide of nitrogen, are subjected to 
 experiment. This substance is very easily prepared, 
 and when dry detonates violently if touched, or 
 even when dropped on water. It is altogether so 
 unstable as to be unfit for any military purposes. 
 Gunpowder, however, is not a chemical compound ; 
 it is only a mixture of materials, the molecules of 
 which are set by art in such positions as do not tend 
 to exercise their natural affinities without external 
 aid. Gunpowder, therefore, is eminently stable. 
 But it is a somewhat intractable explosive, being 
 violent and uncertain in its action, and the rate of 
 its explosion cannot be held under sufficient control. 
 
 However the composition, density, or size of 
 grain be altered, gunpowder does not give the same 
 moderate pressures that can be secured from smoke- 
 less powders, although these are essentially unstable 
 chemical compounds, which undergo rapid decompo- 
 sition, and produce only permanent gases. They 
 have been known for a long time past, but only 
 within the last few years have they received marked 
 attention by every military nation, under the name 
 of " smokeless powders." These are simply violent 
 explosives toned down to such a slow rate of de- 
 composition as to be within the endurance limits of 
 
MODERN GUNS AND SMOKELESS POWDER. 3 
 
 the Strongest metal, steel, now universally employed 
 in the construction of heavy artillery. This process 
 of toning down the rate of combustion can be 
 carried to any reasonable extent ; and now for the 
 first time in history that branch of military en- 
 gineering which includes the designing and con- 
 struction of heavy guns, has been able to reckon 
 upon the most suitable pressures for propelling a 
 projectile with any desired velocity, instead of being 
 obliged to accept the pressures given by the ex- 
 plosion of gunpowder. 
 
 Modern explosives, then, including all smokeless 
 powders, have their molecules in far more intimate 
 propinquity than gunpowder, for they are true 
 chemical compounds, held together by attractions 
 so feeble that they possess an inherent tendency to 
 re-arrange themselves in new gaseous forms, thus 
 eliminating large quantities of nitrogen gas, which is 
 the intruding unstable element in most, if not all, 
 explosives. Any reliable explosive for military or 
 engineering purposes should comport itself to the 
 following conditions : — 
 
 (i.) That it shall not be too unstable, but be 
 safe to manufacture and handle ; 
 
 (2.) That its combustion shall be complete, pro- 
 ducing little or no smoke, no noxious or 
 irrespirable gases, and no residuum ; 
 
 (3.) That it shall not suffer deterioration by time 
 or exposure to ordinary climatic influence ; 
 
 (4.) That it shall not foul the barrel or tube or 
 damage it by excessive heat or pressure ; 
 
 B 2 
 
4 MODERN GUNS AND SMOKELESS POWDER. 
 
 (5.) That it shall have high power with a low 
 specific gravity, so as to give a light 
 cartridge ; 
 (6.) That it shall be uniform in composition and 
 ballistic properties, giving high and regu- 
 lar velocities with moderate and regular 
 pressures, and a flat trajectory; 
 (7.) That its curve of pressures shall approxi- 
 mately follow the requirements for propell- 
 ing a shot. 
 It is the judicious blend of these several qualities 
 that constitutes a good explosive ; and whether the 
 molecules are mechanically mixed, as gunpowder, 
 or held together by chemical affinity like gun- 
 cotton, their action is subject to two sets of laws : 
 one relating to their chemical composition, and the 
 other to their mechanical condition. The new 
 explosives differ from gunpowder only in respect of 
 chemical composition, but they have certain mecha- 
 nical properties, and these can be regulated by 
 similar rules to those which have been so far suc- 
 cessful in adapting modern gunpowder to modern 
 artillery. 
 
 The forces required for propelling a shot, and the 
 principal explosives, will be dealt with in this 
 memorandum from a practical point of view, and an 
 endeavour will be made to place the whole subject 
 clearly before the reader, without encumbering it 
 with mathematical formulae, which too often pass as 
 explanations of things that nobody understands. 
 
MODERN GUNS AND SMOKELESS POWDER. 5 
 
 Influence of Modern Explosives upon 
 Modern Guns. 
 
 As the explosive can now be considered in 
 relationship to the gun, rather than as heretofore 
 adapting the gun to the explosive, it follows that the 
 first place can be given to the necessities of 
 mechanical construction ; and guns need no longer 
 be designed strong enough to resist so violent an 
 explosive as gunpowder. 
 
 Having regard to this freedom, it is intended in 
 the present memorandum to consider the impelling 
 forces upon a shot from a somewhat new point of 
 view, which, although familiar in some degree to 
 engineers, in other applications has not, so far as 
 the authors are aware, been applied to ballistic 
 questions, nor heard of in this country, nor pub- 
 lished abroad. 
 
 At present no acknowledged or established 
 system exists, by which any series of guns can be 
 designed ; all is haphazard and confusion, every 
 nation having its own views, and holding them 
 pertinaciously with much needless mystery. 
 
 An attempt will now be made to place the con- 
 struction of guns upon a systematic basis ; then after 
 having put forward a simple theoretical investiga- 
 tion based upon well-known dynamic laws, other 
 chapters will follow describing modern explosives 
 and machinery required for their manufacture. 
 Gunpowder is by no means so far relegated to the 
 limbo of forgotten things that a short dissertation 
 
6 MODERN GUNS AND SMOKELESS POWDER. 
 
 upon its qualities, properties, and general behaviour, 
 can be considered out of place ; and as these particu- 
 lars form a measure or standard for comparison with 
 other explosives, a full consideration of them cannot 
 fail to prove eminently useful. 
 
 In making this examination, it must be noted 
 that guns and powder are designed and made to 
 suit each other, so it will be desirable in the first 
 instance to ascertain the nature and incidence of 
 those forces, which suffice, and no more than suffice, 
 for producing a given muzzle velocity — that is, the 
 rate in feet per second at which a shot leaves a 
 gun. 
 
 Forces required to Propel a Shot. 
 
 The uniform attractive force of gravity acting 
 upon a falling body, adds equal increments of 
 velocity in equal periods of time, giving a velocity 
 at the end of one second equal to 32*2 feet ; but a 
 sudden evolution of gases in the chamber of a gun 
 produces a high initial pressure, which gradually 
 diminishes as the gases expand, lowering their 
 temperature and accelerating the shot, until its full 
 muzzle velocity has been acquired ; all this is done 
 within a fractional part of a second of time. 
 
 The explosion of gunpowder thus differing 
 altogether from the action of gravity, a shot does 
 not receive equal increments of acceleration in equal 
 times, as it would do if under the influence of a con- 
 stant pressure like gravity, but it occupies a position 
 
MODERN GUNS AND SMOKELESS POWDER. 7 
 
 analogous to that of a steam-engine piston, accele- 
 rated during the first half of its stroke by the ex- 
 pansion of high-pressure steam, or like the piston 
 of a gas-engine, accelerated in like manner by an 
 explosion of mixed gases. 
 
 Before a manufacturer can be expected to pro- 
 vide a suitable explosive for any given rifle or gun, 
 it is obviously desirable that he should understand 
 something as to the actual conditions under which a 
 shot should be impelled. 
 
 The present memorandum has been written, not 
 as a complete essay on the manufacture of rifled 
 ordnance, but only treating the subject so far as 
 may be necessary for guidance in the production of 
 suitable explosives for rifles, machine guns, or 
 heavy ordnance. Knowing the muzzle velocity 
 sometimes erroneously called " initial velocity," 
 and the distance a shot travels in the gun before 
 being discharged — knowing also its weight and 
 diameter, the average pressure required to impart 
 this velocity can be ascertained from the ordinary 
 laws of dynamics. Again, knowing the final pitch 
 of rifling and rotations of the shot per second, the 
 pressure necessary to produce this rotation can also 
 be easily calculated. Expelling such air as is found 
 in the bore and overcoming friction are items 
 which some writers take notice of, but which are so 
 utterly insignificant in comparison with the heavy 
 pressures required for impelling the shot, that no 
 practical objection exists to omitting them al- 
 together. Even the pressure required to give 
 
8 MODERN GUNS AND SMOKELESS POWDER. 
 
 rotation to a shot amounts to no more than a small 
 fraction of a ton per square inch. Formerly the 
 action of studs upon the rifling absorbed consider- 
 able power before the gas check was invented, yet 
 this was not a legitimate frictional resistance, but 
 was due to inadequate surfaces exposed to pressure. 
 
 The object all gun constructors have in view is 
 to give the highest possible muzzle velocity to a 
 shot with a minimum strain upon the gun, and" this 
 must be accomplished with due regard to an econo- 
 mical expenditure of powder. 
 
 A high initial pressure developed in the space 
 formerly occupied by a solid explosive is succeeded 
 by expansion driving the shot before it by forces 
 which decrease with great rapidity, and the gun is 
 like a steam-engine working with a very high rate 
 of expansion in a single cylinder, without the chance 
 of any gain by compounding ; and the usual pres- 
 sure curve of fired gunpowder is far from repre- 
 senting a sequence of pressures conducive to 
 longevity in a gun. 
 
 Indeed, their destructive effects become power- 
 fully conspicuous in the larger class of heavy guns, 
 where the metal is often subjected to strains beyond 
 its elastic limits, and dangerously near to its point 
 of final rupture. 
 
 The numerous attempts to remedy this state of 
 things attest the extent of the evil. Selecting a 
 slow-burning powder, enlarging the size of the 
 grains, and increasing their density, are legitimate 
 remedies ; but when it comes to allowing an air 
 
MODERN GUNS AND SMOKELESS POWDER. 9 
 
 space for unapplied expansion, the remedy becomes 
 a manifest waste of energy that ought to be reserved 
 for impelling the shot. 
 
 It is so much more satisfactory to follow any line 
 of argument by observing its practical application, 
 than by using letters, symbols, or mathematical 
 formulae, that this system will be adopted in the 
 present memorandum, and it is intended to take 
 advantage of an old, some may say " out of date," 
 but singularly instructive experiment — an experiment 
 conducted with the greatest care and accuracy, and 
 well known to all artillerists. This will be used to 
 exemplify a theory newly applied to gunnery and 
 the practical results arising therefrom. In this 
 experiment a 38-ton Armstrong gun I2'5 inches 
 calibre was provided with numerous Crusher gauges 
 for ascertaining the pressure at every part of the 
 travel of the shot, and electrical appliances were 
 also used, whereby its velocity could be tabulated, 
 and one set of data thus served as a check upon the 
 other. 
 
 Experiments on 38-TON Gun. 
 
 The following data are given in relation to experi- 
 ments on this gun. The letters preceding are the 
 same as are recommended for symbols in the ' Text 
 Book of Gunnery.' 
 
 Diameter of calibre . . =12-5 inches. 
 
 Charge of i^" cubical powder = 130 lbs. 
 
 Area of base of shot . . =122-7 square inches. 
 
lO MODERN GUNS AND SMOKELESS POWDER. 
 
 Length of cartridge 
 
 Length of bore . 
 L = Travel of shot 
 w = Weight of shot 
 z> = Muzzle velocity 
 Rifling commencing at i 
 
 = 1-6 feet (about). 
 
 = i6'6 feet. 
 = 15 feet. 
 = 800 lbs. 
 
 = 1400 feet per second, 
 turn in 438 calibres, con- 
 cluding at I turn in 35 calibres, equivalent to 
 I turn in 36*45 feet. 
 P = Total pressure in tons per square inch on the 
 
 shot. 
 /> = Mean pressure in tons per square inch on the 
 
 shot. 
 y = Acceleration or retardation in feet per second. 
 g = Acceleration of gravity 32*2 feet per second, 
 i = Radius of gyration of shot in feet. 
 
 7000 grains troy . . . . = i lb. avoirdupois. 
 
 „ . Shot 800 lbs. ^ „ . , 
 
 Ratio r- 1-u = :: = 6* SS lbs. per square nich. 
 
 Calibre i22'7 ^^^ ^ ^ 
 
 The first column in Table L gives the length of 
 bore 1 6 • 6 feet, of which i ■ 6 are occupied by the 
 cartridge, leaving 15 feet as the length which the 
 shot travels in acquiring a muzzle velocity of 1400 
 feet per second. The second column gives pres- 
 sures in tons at each foot in the gun, ascertained by 
 means of Crusher gauges. The third column gives 
 observed velocities, at positions corresponding with 
 the different pressures, and the fourth column shows 
 the differences between those velocities — that is to 
 
MODERN GUNS AND SMOKELESS POWDER. II 
 
 say, it gives the rate of acceleration (/) which occurs 
 as the shot travels on its course, till it leaves the 
 muzzle ; and it is the sum of all these accelerations 
 which makes up the final velocity of 1400 feet per 
 second. The fifth column is deduced from the 
 second, and gives the mean between each of these 
 
 TABLE 
 
 pressures, which add up to 95*5; and this figure, 
 divided by 15 spaces, shows an average pressure of 
 6*37 tons per square inch — observed pressure on 
 the shot. It is important to remember that pressure 
 produces velocity through increments of accelera- 
 tion ; and that velocity, as such, absorbs no pressure. 
 
12 MODERN GUNS AND SMOKELESS POWDER. 
 
 but alterations in the rate of acceleration absorbs 
 all the pressure, and this rate may be taken as 
 a maximum when the shot begins to move from a 
 state of rest. 
 
 The rate of acceleration thenceforth diminishes, 
 until it becomes zero, when the shot has acquired a 
 full muzzle velocity and quits the gun.* 
 
 In considering the pressures most desirable for 
 propelling a shot, with any given muzzle velocity, it 
 is only necessary, therefore, to take note of the 
 incidence of those forces which go to produce 
 acceleration, for the mean pressure is fixed by the 
 laws of dynamics, and cannot be altered. 
 
 The pressures from Column 2, Table I., are laid 
 down like an indicator diagram in Fig. 2, and they 
 constitute important data ascertained from the 38- 
 ton gun. 
 
 Curve of Pressure. 
 
 Here, in Fig. 2, 
 
 A, B, = the travel of the shot to a scale of -}q 
 inch to I foot (L = 15 feet). 
 
 A, c, = the total pressure in tons per square inch 
 indicated by the letter P, and drawn to a scale of 20 
 tons = I inch. 
 
 A, G, = the space taken up by the cartridge, i • 6 
 feet in the present example. 
 
 * The whole theoretical argument by which this conclusion is 
 justified will be found in ' A Practical Treatise on the Steam 
 Engine,' by Arthur Rigg. 
 
MODERN GUNS AND SMOKELESS POWDER. 
 
 13 
 
 Ordinates upon a, b, represent pressures at every 
 foot, and the curved line c, b, corresponding to 
 those pressures, shows their variation and range, 
 and gives an average of 6-37 tons per square inch, 
 as shown by a, d, = p. 
 
 The total amount of energy is represented by the 
 rectangle a, d, e, b, and the portion lying behind a 
 as far as g is filled up by the cartridge, and represents 
 an amount of pressure, much of which is lost so far 
 
 Fig. 2. 
 
 as propelling is concerned. This space corresponds 
 with the clearances in a steam-engine cylinder, and 
 should be reduced to a minimum. 
 
 Whatever may be the exact sequence of changes 
 which accompany the explosion of gunpowder, it is 
 well known that only the smaller portion, or about 
 43 per cent, of the total products, become permanent 
 gases, while the remaining 57 per cent, of inert 
 matter assumes the form of a finely divided vapour, 
 
14 MODERN GUNS AND SMOKELESS POWDER. 
 
 which is the well-known cloud of smoke accom- 
 panying the use of gunpowder. This large portion 
 of inert matter occupies considerable space in the 
 cartridge — space which has to be filled by vapour of 
 the full initial pressure, and is no more than a sort 
 of buttress against which the pressure acts which 
 impels the shot, and in this capacity it is neither 
 better nor worse than the base of the bore itself 
 which costs nothing to fill. 
 
 Herein lies one advantage derived from the use 
 of smokeless powder. As its cartridge takes little 
 more than half the space of a gunpowder cartridge, 
 giving equal propulsive power, so a correspondingly 
 larger part of projectile force can be applied to 
 the shot instead of filling up a vacancy which 
 pure theory would altogether abolish. 
 
 In order to make the subject complete, it will be 
 convenient to note that the average pressure in tons 
 per square inch required for propelling a shot may 
 be calculated according to the ordinary laws of 
 dynamics by the following formulae, using the 
 symbolical letters already given on page lo. 
 
 Mean pressure = -k r = 
 
 ^ A X L X 2240 X 2g 
 
 800 lbs. X 1400'' 
 122-7 X 15 X 2240 X 2 X 32-2 ~ 5 ■ 9 tons per 
 
 square inch. 
 
 This, then, is the mean amount required to give 
 the shot a muzzle velocity of 1400 feet per second ; 
 but there must be added to it sufficient pressure for 
 
MODERN GUNS AND SMOKELESS POWDER. 1 5 
 
 rotating the shot, expelling the air, and overcoming 
 friction in the grooves, &c., so the results of calcu- 
 lation may be taken as being in close agreement 
 with 6 '37 tons, obtained by direct measurement; 
 and these figures mutually tend to confirm each 
 other. , 
 
 Although all artillerists may not agree with the 
 arguments and theories following, yet, so far as 
 these figures are concerned, they are practically 
 common ground, and it is only with the incidence of 
 those varying pressures which make up this mean 
 pressure that there is any room for differences of 
 opinion. 
 
 So far as it appears by an inspection of Fig. 2, the 
 pressure, commencing at 23 '8 tons per square inch, 
 and running down to • 6 tons (a variation of 40 to i ) 
 indicates strains of a most irregular character — 
 higher than needed for the commencement, and 
 lower than they ought to be towards the middle 
 and end of the travel. 
 
 Natural Law of Acceleration. 
 
 It will now be interesting to inquire whether any 
 natural law of acceleration prevails in other corre- 
 sponding cases. Such a law we find in the move- 
 ment of planetary bodies, in the acceleration of a 
 train commencing to run up an incline, in the piston 
 of a steam engine during the first half of each 
 stroke, and in the acceleration of a stone from a 
 sling. 
 
i6 
 
 MODERN GUNS AND SMOKELESS POWDER. 
 
 The very earliest form of projectile would natu- 
 rally be a stone discharged from a sling, and an 
 examination of the laws involved in its operation 
 gives a clue for ascertaining the minimum pressures 
 that must be provided for accelerating a shot to any 
 desired muzzle velocity, should it be intended that 
 the shot shall obey the same laws that govern 
 
 Fig. 3. 
 
 the operation and course of a sling-stone. Fig. 3 
 represents a stone r revolving round a centre e, at 
 the radius a, b, and loosed at R. It would then travel 
 along a tangential line with a circumferential 
 velocity that may be designated by the vertical line 
 R, B ; the length of the arc a, r and spaces i, 2, 3, 
 &c., into which this arc is divided, representing 
 
MODERN GUNS AND SMOKELESS POWDER. 1 7 
 
 equal intervals of time ; for example, if a, r should 
 be 30 part of a second, then the several spaces 1,2; 
 2, 3 ; &c., each represent yj^ of a second. 
 
 When the stone is passing the point A it is 
 travelling vertically, and has no horizontal com- 
 ponent to its motion — that is, component in the 
 direction of A, b ; but gradually its direction changes 
 to one parallel to a, b, with the same velocity which 
 it had perpendicularly when at A. The centrifugal 
 force of the stone always acts radially, and is an 
 exact measure of the initial pressure which would 
 be required for giving a similar projectile at A its 
 initial acceleration along A, b, in the direction of the 
 arrow. 
 
 As a projectile is fired from the gun shown in 
 half section. Fig. 3, it travels from a to b with a 
 velocity variable, but increasing by increments of 
 acceleration until the maximum amount, represented 
 by B, R, on a vertical scale, is reached. The 
 necessary force absorbed by acceleration meanwhile 
 grows smaller and smaller by irregular decrements, 
 until at B it vanishes altogether. If the full length 
 of the line A, b be taken at any suitable scale to 
 represent this initial accelerating pressure, ascer- 
 tained by calculation, then pressures corresponding 
 to successive equal periods of time are given on the 
 same scale on a, b by perpendiculars drawn upon it 
 as shown by dotted lines in Fig. 3, starting in every 
 case the measurement from B to the point marked 
 5, 7, 9, &c., where the perpendiculars fall from 5,' 
 
 7', 9', &c. 
 
 c 
 
i8 
 
 MODERN GUNS AND SMOKELESS POWDER, 
 
 These lengths are brought down to a uniform 
 base in Fig. 4, and their terminations will be found 
 to lie in a diagonal line, L, B, which represents a 
 gradual and regular diminution of the impelling 
 forces from a maximum to zero. 
 
 Thus ordinates from A, b, drawn up to the diagonal 
 line L, B, give exact measurements of the uniformly- 
 
 diminishing pressures required to produce accelera- 
 tion according to the system which prevails with a 
 sling-stone. 
 
 These Figs, 3 and 4 portray the operations of a 
 natural law, which indicates how the highest possible 
 velocity can be obtained with the lowest initial 
 
MODERN GUNS AND SMOKELESS POWDER., 1 9 
 
 pressure, and with some regard to the economical 
 application of power, expansion, and continuous 
 burning, as contrasted with a sudden explosion. 
 This somewhat new view of the question may. 
 very properly be tested by application to the pres- 
 sures and velocities of a shot during its travel in 
 a gun. 
 
 Presuming the shot to follow the same sequence 
 of accelerations as a sling-stone, it will be found 
 that the considerations determining the strength of 
 the sling are exactly the same as those to be applied 
 to the component parts of a gun. 
 
 If a shot of the same weight as the stone at R 
 were discharged with the same muzzle velocity after 
 travelling along a gun of the length A, b, then the 
 maximum pressure that would be necessary for 
 imparting the first acceleration would be found equal 
 to the centrifugal force at A, and this pressure would 
 diminish by regular instalments to zero, when the shot 
 is discharged at B with its muzzle velocity complete. 
 
 The centrifugal force of any revolving body may 
 be calculated from the formulae : — 
 
 Centrifugal force = weight of body x revolutions 
 per minute^ x radius in feet x -000341. 
 
 The shot travels from A to b, and its muzzle 
 velocity is assumed equal to b, r, being the same as 
 that of the sling-stone discharged at r. 
 
 Here divisions i, 2, &c., upon the quadrant A, r, 
 represent, as before, equal intervals of time, and 
 may be plotted down upon a, b, as in Figs. 3 and 4, 
 
 c 2 
 
20 MODERN GUNS AND SMOKELESS POWDER. 
 
 for illustrating the pressure upon the shot at any 
 part of its travel along the gun. 
 
 By adopting these general principles, and as- 
 suming any desired muzzle velocity, it is easy to 
 ascertain by a graphic method, assisted by a very 
 simple mathematical formulae, the pressure required 
 for acceleration, also the rate of acceleration, and 
 the actual velocity which the shot possesses at any 
 point of its travel. 
 
 The calculation can also be reversed for the pur- 
 pose of ascertaining the muzzle velocity for any given 
 powder pressure. 
 
 As it is very convenient to reduce all calculations 
 of this kind to a common basis for comparison, 
 the shot may be considered as weighing so many 
 pounds per square inch upon its base. 
 
 The initial and average powder pressures, whether 
 in rifles or heavy guns, will also be worked out in 
 terms of tons per square inch. 
 
 The principles so far, as already stated, apply to 
 smooth bores, but when rifled ordnance is concerned, 
 it is obvious that some additions must be made to 
 provide for rotating the shot, expelling the air, over- 
 coming friction, and other minor resistances. 
 
 A little examination, however, shows that these 
 extra resistances sink into insignificance as compared 
 with the forces required to give the necessary muzzle 
 velocity, and they may best be taken in order, 
 beginning with the effects of rifling. 
 
MODERN GUNS AND SMOKELESS POWDER. 
 
 21 
 
 Rifling. 
 
 Whether rifling is carried out with an increasing 
 pitch or not, its final effect is the same in producing 
 rotation at the rate of so many turns in a second 
 of time ; and the mean force is applied at some 
 radius and not at its periphery. 
 
 This radius is the "radius of gyration," and is 
 
 
 Fig. s. 
 
 illustrated by the end elevation of a conoidal shot, 
 Fig. 5. Here s, t represents the radius of a rifled 
 shot, and t, v its corresponding radius of gyration, 
 this being approximately f s T = k. 
 
 If the pitch of rifling be uniform, its rotation takes 
 place by the very same increments of acceleration 
 as those by which the shot itself acquires velocity ; 
 but this is not the case with an increasing pitch. 
 
22 MODERN GUNS AND SMOKELESS POWDER. 
 
 An engineer constructing a railway, and desiring 
 to change from a level to a gradient, would never 
 begin at the full inclination, but would make its 
 commencement gradual, according to a parabolic 
 curve or the arc of a circle whose centre is high up 
 -in the sky. 
 
 This corresponds exactly with an increasing pitch, 
 and for similar reasons the designer of a gun adopts 
 that system in order to lessen the excessive strain 
 caused by a too sudden evolution of powder gases. 
 
 Whenever the powder pressure exceeds the 
 natural requirements of a shot, the rifling adds an 
 extra strain upon the already excessive pressure 
 required for starting it, and that too upon a part of 
 a gun already severely loaded to compensate for 
 deficient pressures later on. 
 
 Uniform pitch thus produces a higher initial rota- 
 tion than would be necessary if every inch of the 
 bore took its proper share in giving the final muzzle 
 velocity. 
 
 The first elements of an increasing pitch are there- 
 fore made almost parallel with the axis of a gun, 
 and the greatest strain of rotation is postponed so as 
 not to coincide with the greatest initial pressure for 
 impelling the shot, for this occurs just at the com- 
 mencement of its travel. 
 
 Increasing pitch is therefore nothing else than a 
 compensation for any powder that gives an excessive 
 initial pressure, and it transfers the strain of rotation 
 from the breech towards the muzzle of a gun. 
 
 It is thus only permissible to have a uniform 
 
MODERN GUNS AND SMOKELESS POWDER. 23 
 
 pitch when the shot can be started at so moderate a 
 speed, and by such moderate pressure that its pro- 
 jection and rotation shall follow the sequence of 
 some such law as prevails with the acceleration of a 
 sling-stone, and with this latter system alone it would 
 seem that increasing pitch can be abandoned for 
 uniform pitch. 
 
 Pressure Required to Rotate a Shot. 
 
 General Particulars, 
 
 Taking an illustration from the most complete 
 series of experiments published, namely, the 38-ton 
 Armstrong gun, page 11, its rifling has increasing 
 pitch from i turn in 438 calibres to i turn in 35 
 calibres, or 36-45 feet at the muzzle. 
 
 The diameter of the shot . =12*5 inches. 
 
 Its circumference . . . =3*27 feet. 
 
 Its weight = 800 lbs. 
 
 , . r- ■ 1400' X 3*27 
 The velocity of its circum- | — 
 
 ference .... 
 
 feet per second. 
 
 Assuming the radius of gyration upon which 
 pressure acts, as being \ that of the shot, 
 
 The velocity at its radius of gyration = 
 ^-^ = 83-8 feet per second ; 
 
24 MODERN GUNS AND SMOKELESS POWDER. 
 
 the mean pressure per square inch on base of shot 
 to produce this rotation = 
 
 A X L X 2240 X 2g 
 
 800 X 83-8= 
 
 2 = "02 tons per square inch, 
 
 I22-7X 15 X 2240x64*4 ^ ^ 
 
 an amount so small that it may practically be 
 neglected in comparison with the forces required for 
 propelling the shot. 
 
 Friction. 
 
 The co-efficient of friction differs according to the 
 nature of surfaces and varies from -^q to j% for metallic 
 surfaces in contact. 
 
 The liquid products of ordinary gunpowder pos- 
 sess certain lubricating properties, but this is not so 
 with smokeless powders, as at present constituted. 
 It may therefore be assumed that a higher co- 
 efficient of friction must be reckoned for with the 
 new powders. 
 
 Taking however ^^ of the weight as the 
 co-efficient of friction, this shows a pressure of 
 800 lbs. X •2=160 lbs., very little more than i lb. 
 per square inch of the area of the bore, an amount 
 that may very well be neglected when dealing with 
 many tons or corresponding areas. 
 
MODERN GUNS AND SMOKELESS POWDER. 25 
 
 Comparison between Results Observed 
 and Calculated. 
 
 Having now obtained experimental and theoreti- 
 cal results concerning those forces which act within 
 a gun, it will be convenient to make a comparison 
 and research as to the information that can be 
 derived from these particulars. 
 
 Here the graphic method of calculation will facili- 
 tate the investigation, and prove more instructive 
 also than tables of figures. 
 
 The various pressures tabulated on Fig. i are 
 laid down, like an indicator diagram of a steam- 
 engine, in Fig. 2, and re-arranged according to the 
 general ideas explained, in connection with Fig. 3, 
 in another diagram, Fig. 6. Here the horizontal 
 line A, B gives the travel of the shot (15 feet) to the 
 lower scale into which it is divided. 
 
 Where vertical ordinates from A, b, intersect the 
 curve of velocity, their lengths from A, b, vertically 
 represent velocities at given points, to the scale of 
 velocities on b, r. 
 
 The same horizontal line A, b is also used to 
 another special scale, to show tons per square inch 
 upon the base of the shot ; so where vertical lines 
 from A, B, cut the curve of pressure, the length 
 measured from b, r, gives tons per square inch on 
 the horizontal scale, while corresponding velocities 
 in feet per second are given by vertical lines as 
 shown, dotted across to the vertical scale, b, r. 
 
26 
 
 MODERN GUNS AND SMOKELESS POWDER. 
 
 It can hardly fail to be noticed how in this 
 diagram the curve of velocities very closely ap- 
 proaches the quadrant of a circle, and this agrees 
 with the corresponding ideas represented by Fig. 3. 
 
 TONS 
 T^RA> ^ OF SHOT -FEET- 
 12345678910 II 12 13 14 l|5 
 
 Fig. 6, 
 
 Results. 
 
 By experiment it appears that an initial pressure 
 of 23 "8 tons per square inch is given to the shot for 
 its original acceleration ; although by calculation it 
 
MODERN GUNS AND SMOKELESS POWDER. 27 
 
 turns out that half of this pressure, or 12 tons per 
 square inch, would have been sufficient. At 5 feet 
 6 inches of the travel, being about half the time 
 during which the shot is in the gun, the pressure 
 ascertained by experiment agrees with that calcu- 
 lated by this theory, but at half the travel the 
 pressure is only 2^ tons, whereas it ought to be 
 the mean, or 6 tons. 
 
 Thus 5 feet 6 inches of the gun is overstrained 
 in order to make up for want of pressure during the 
 remainder of its length. For this reason an excess of 
 metal is required toward3 the breech, as commonly 
 shown by the guns at present in the English service, 
 but the new French guns for smokeless powder are 
 stronger towards the muzzle, and better propor- 
 tioned towards the breech. The highest initial pres- 
 sure given by the Crusher gauge in this experiment 
 was 23 '8 tons per square inch, and if this were to 
 follow the fine dotted line c, b, Fig. 2, it would rep- 
 resent an average pressure competent to impart a 
 muzzle velocity of 2094 feet per second. 
 
 The conclusion, therefore, . is that to secure a 
 velocity of 1400 feet, this particular gun was 
 subjected to an initial strain that would have sufficed, 
 if properly followed up, to produce a velocity of 
 2094 feet per second. Fig. 7 is a diagram similar 
 in general design to Fig. 6 ; but in this the initial 
 pressure is taken as 12 tons per square inch by 
 using a different scale for tons, but the same scales 
 for travel in the bore and for acceleration and velo- 
 city. In Fig. 7 the same muzzle velocity is given 
 
28 
 
 MODERN GUNS AND SMOKELESS POWDER. 
 
 and the same sequence of pressures is followed as 
 that which prevails with a sling stone. 
 
 Both the curves for pressure and velocity are 
 drawn so as to coincide accurately with the qua- 
 
 TTT 
 
 TONS 
 TRAVEL OF SHOT-FEET- 
 
 TT— r 
 
 Tj— ir-Tj— ir 
 
 r I 2 3 4 5 6 7 8 9 10 II 12 13 14 Il 5 
 
 Fig. 7. 
 
 drant a, r. This quadrant also represents the 
 total time the shot remains in the gun, and its equal 
 divisions represent equal fractions of a second. 
 This diagram therefore supplies the following 
 different classes of information : — 
 
MODERN GUNS AND SMOKELESS POWDER. 
 
 29 
 
 1. Muzzle Velocity = 1400 feet per second. 
 
 2. Accelerated Velocity = a. maximum from the 
 commencement to zero at termination. 
 
 3. Proper Pressure per square inch at commence- 
 ment and throughout travel of shot. 
 
 1400 R 
 
 
 
 
 
 
 *^^ 
 
 ii^~ 
 
 
 
 
 
 // 
 
 h z 
 
 
 
 
 ^ 
 
 ^ 
 
 r 
 
 1006 
 
 t^ 
 
 
 5= 0: 
 
 
 
 / 
 
 /7 
 / 
 
 
 500 
 
 to. 
 
 p UJ 
 
 
 y 
 
 / 
 
 / 
 
 
 
 L 2 
 
 p >- 
 [=1- 
 
 •TO 
 
 mif 
 
 / 
 
 
 f 
 
 
 . 
 
 F > 
 
 T 
 
 T^'n 
 
 inrT 
 
 irthTT 
 
 WTT 
 
 innr 
 
 B 
 
 4 
 
 20 
 
 15 
 
 10 
 
 5 
 
 
 
 
 TONS 
 
 Fig. 8. 
 
 4. Position of Shot at any fraction of time during 
 its travel. 
 
 As the tons in Figs. 6 and 7 are drawn to diffe- 
 rent scales, they do not very well represent their real 
 differences at a glance, so they are repeated in 
 Fig. 8, and both drawn to the same scale ; so, by 
 
2,0 MODERN GUNS AND SMOKELESS POWDER. 
 
 comparing Figs. 6 and 8, it now becomes easy to 
 see how much greater strain is put upon the gun 
 than is necessary to do the resulting work. 
 
 Foreign Guns. 
 
 Very few particulars are published as to the 
 performances of foreign guns, and the data given 
 never seems to be sufficient for working out com- 
 plete results. It is not, therefore, by any means 
 easy to make proper comparison between the 
 different ideas embodied in their construction and 
 in those which prevail among ourselves. 
 
 The present fashion tends rather towards the 
 production of guns of abnormal length, and as 
 length figures in the denominator of the equation, 
 by which the mean pressure to propel a shot at a 
 given muzzle velocity, is ascertained ; it follows 
 that this pressure might be expected to reduce in 
 direct proportion to the length of a gun. Conse- 
 quently, when the highest workable pressure has 
 been reached, beyond which the materials at 
 disposal can endure no further strain, there would 
 seem no simpler way for increasing the velocity 
 than by elongating the gun. This, however, cannot 
 be carried very far without producing a weak un- 
 wieldy weapon, one in which an excessive vibration 
 becomes set up towards the muzzle ; and this not 
 
MODERN GUNS AND SMOKELESS POWDER. 3 1 
 
 only damages the gun, but is prejudicial to all 
 accuracy of aim. One cause of this excessive 
 vibration in long guns is not far to seek, and it 
 arises from the unbalanced rotation of a shot. All 
 rotating bodies tend to rotate round their centre of 
 gravity, so that unless a shot is truly balanced about 
 the centre line of its longitudinal axis, it will rotate 
 around some other centre, and thus become an 
 excentric mass rotating at a high speed, and setting 
 up vibration of an intensity that grows rapidly with 
 the rate of its rotation, and that increases with the 
 length of the gun. If for no other reason than this, 
 artillerists will find the utter uselessness of carrying 
 length too far in a gun,* unless, indeed, they are 
 prepared to balance every shot and shell round its 
 larger axis. This element of vibration is so uncertain 
 in the periodicity of its operation, or in the duration 
 of its effects, that it cannot be made the subject of 
 exact calculation ; because nobody knows what 
 accidental vibrations may accompany the want of 
 balance in each particular shot. 
 
 It would be very costly to balance every shot, and 
 absolutely impossible to -balance every shell around 
 its central axis; the only thing certain about the 
 whole matter is that vibration means a waste of 
 power in the shot, that it does much harm to the 
 gun, and destroys all accuracy of aim. 
 
 * It is a well-known fact that there are guns of long calibre in 
 the British Service which have been permanently injured by 
 vibration having caused the muzzle to drop; and this has 
 happened even during the ordeal of testing such guns. 
 
32 MODERN GUNS AND SMOKELESS POWDER. 
 
 The inferences deducible from this argument 
 seems to be that it is altogether unsafe to assume 
 that pressure reduces without any Hmit in exact 
 relationship to the length of a gun ; and any theory 
 accepted on this basis will be as misleading as 
 theories usually are found to be when founded upon 
 partial data, omitting all consideration of the en- 
 circling facts. Even accepting the cautions im- 
 plied by this discussion, it will still be interesting 
 to select some foreign guns for comparison, and to 
 calculate the results obtained on the basis that the 
 data given are correct.* 
 
 Thus it is only the assumption that the shot or 
 shell used in certain experiments with guns of long 
 calibre have been carefully turned and balanced, that 
 the reported high accuracy can be secured. 
 
 Tolerably complete data have been published in 
 ' Engineering,' concerning the performance of the 
 French " Canet " guns, and of the designs adopted 
 by the United States Government. Our own War 
 Office have, with the greatest liberality, furnished 
 exact data of three important and representative 
 guns, showing the most, recent practice in the 
 British Service (1892). 
 
 Table 3 gives these results in a simple accessible 
 
 * It is a curious fact that although guns are bored to gauges, 
 with a limit of variation of ^^w V^^^ of an inch, this exactitude 
 is never maintained after a few trial shots are fired. It is a more 
 curious fact that shot and shell for use in these same guns are not 
 manufactured with any accuracy at all, but are roughly fitted to 
 size by an ordinary grindstone, leaving the gas-check to do the 
 rest. 
 
MODERN GUNS AND SMOKELESS POWDER. 
 
 33 
 
 
 a 
 .2 
 
 •a s 
 
 w lo^ CO 0v3^o CON li-)C^^^c^O^ 
 
 5w"^cr»M ror-*tr> roco o -^ -i>. m u^ 
 
 
 „; i-o 'OOoooor^O^^>. 
 C (N CO 0^ u-)O0 CO VO M « t|-00 On On 
 
 ■*-• -o r^ -^ mo 00 r^-o ONint^co x-»j>. 
 
 O . 
 
 11 
 
 i in 00 00 "roVi N vo O 
 O lo m U-) xn^o 00 h h onOnonioio 
 
 looo N r^N !>. vi- o\ o\ in xn o o h 
 
 w 
 
 V 
 
 o 
 
 1 
 
 N , C^ 
 
 . . . ' I . . . '-' ; o ; ; ; 
 
 lA <N ' * * 
 
 N 
 
 
 « § g wlw 
 
 .—1 <!J 
 
 ■S ^ 
 
 IT) lO 
 
 m °° ^ . t^ . N . . . 
 
 
 
 5 o 
 Sen 
 
 00 
 
 M ro in 
 
 _SO000 ■ ■oiorf-^roroOOO 
 
 ?5OO0O Or~HM OOOOO 
 
 OOmh com nrON 
 
 M 
 
 MO 
 
 VO (j CO « 
 
 ^ O O '-' "^ 
 HI c^ ro '^ IT) w N 
 
 1 
 
 u-l ir^ O 
 
 ^ \n osONO\ ooooONio 
 'o « »0 m lO ir)O0 O cOfOM iHVO Osro 
 
 .3 " " " 
 
 
 a « 
 
 |2 : 
 
 i^^ •. -.^ , 
 
 PI a "-) en di ■ ■ 5:;^ i 
 
 22: ..^ ,es ,,S^^ 
 
 G a t3 1^ "* o .S " • 
 
 
 
 
34 MODERN GUNS AND SMOKELESS POWDER. 
 
 form ; and it will be observed that no data are 
 given with smokeless powders, as in the present 
 somewhat experimental state of this class of ex- 
 plosive, the results might be subject to considerable 
 future modification. 
 
 These examples may serve to show partly what 
 is expected from the guns by their designers, as 
 some of the data given appear to have been 
 obtained by calculation and not by direct experi- 
 ment. Such of these data as are useful for the 
 present inquiry are given in the subjoined Table 
 III., together with corresponding data from the 
 38-ton Armstrong gun for comparison. 
 
 The last three columns are obtained by calcu- 
 lation, and they give the travel of shot, and the 
 initial pressure. These initial pressures are in 
 every case taken as equal to twice the average, and 
 this gives the rate of acceleration similar to that 
 already explained on page 16, in connection with 
 
 Fig. 3- 
 
 It will be seen that the Armstrong 5-5 ton quick- 
 firing 6-inch gun, with a muzzle velocity of 2339 
 feet per second, requires an average of 7*25 tons 
 per square inches initial pressure, while the 
 " Canet," 15 c/m gun of 5' 9 inches diameter, which 
 is practically the corresponding French size, requires 
 4-8, '5 "9, and 6-5, tons per square inch, according 
 to length, to propel a shot 1640, 2165, and 2559 feet 
 per second, respectively ; this velocity increasing in a 
 higher proportion than length of calibre. From the 
 United States trials, it would appear that their 
 
MODERN GUNS AND SMOKELESS POWDER. 35 
 
 8-inch gun, carrying a 300 lbs. shot, with a muzzle 
 velocity of 1935 feet, requires 16 tons per square 
 inch of black gunpowder, or 14-3 tons with smoke- 
 less powder, but as the smallest possible initial 
 pressure required to accomplish this work is 17-6 
 tons, excluding whatever power goes for rotating the 
 shot, it is evident that the data quoted are wrong 
 somewhere. 
 
 The United States lo-inch gun, having a 575 lb. 
 shot, discharged at 1953 feet per second, is stated 
 to require 16 • 6 tons initial pressure, and as cal- 
 culation gives 1 5 • 6 tons without considering the 
 rotation of the shot, this experiment may be nearly 
 correct. 
 
 An interesting series of examples are given at the 
 end of Table 3. These are the most recent English 
 guns, 6 inch, 9*2 inch, and 13" 5 inch, and the data 
 have been liberally furnished by the authorities at 
 the War Office. From these data it has been 
 calculated that the maximum initial pressures to 
 impel the shot, leaving out of consideration all that 
 goes for rotation, etc., are 17 '74 tons, 15 "08 tons, 
 and 1 5 • 94 tons respectively. 
 
 These proportions show diminishing pressures 
 combined with increasing bores, and this points 
 towards an approach to some regular and systematic 
 principles having been considered when designing 
 these guns. 
 
 D 2 
 
2,6 MODERN GUNS AND SMOKELESS POWDER. 
 
 Conclusions as to Guns. 
 
 If it were possible in actual practice to get a full 
 theoretical result out of an explosion of gunpowder, 
 in exact accordance with the system of acceleration 
 suggested, then ordinates to the diagonal line l,b, 
 in Fig. 2, would represent the exact pressures at 
 every point required to produce the characteristic 
 curve of accelerations represented by vertical 
 ordinates from a base line a,b, to the quadrant 
 of a circle a,p, in Fig. i. But such a purely 
 theoretical result is not even wholly desirable, even 
 if it were possible in practice. For example, it 
 would not be worth while to expand the gases down 
 to atmospheric pressure, as the gain by doing this 
 would require an inconvenient addition to the length 
 of a gun, which is very objectionable for reasons 
 already explained. 
 
 The powder pressures, therefore, should never be 
 fully exhausted when the shot leaves the gun. 
 Again, supposing a theoretically perfect result were 
 attainable, it would become necessary to provide 
 special powder for every kind of gun, and this is 
 plainly out of the question. So long as small arms 
 and heavy guns of different calibres are used in the 
 service, there must of necessity be some difference 
 in the powders ; and how to balance the advantages 
 and disadvantages of any desired compromise is a 
 difficult and yet unsettled question. In any case, it 
 would seem that there must be at least three kinds : 
 
MODERN GUNS AND SMOKELESS POWDER. 37 
 
 one for rifles or machine guns, another for field 
 artillery, and yet another for heavy ordnance. 
 
 Everything, therefore, that can be considered 
 practically possible with any theoretical proportions 
 adopted, is to accept a sequence of pressures, with 
 its corresponding rates of acceleration as a general 
 guide only, and then to make the best possible 
 approximation to this, or, indeed, to any system 
 which may be accepted as a standard. 
 
 The foregoing illustrations and arguments there- 
 fore indicate rather the thing to be sought for in all 
 explosives used for guns then, as giving results that 
 should be implicitly followed under all conceivable 
 circumstances and conditions. 
 
 As the composition, rate of combustion, and me- 
 chanical condition of the new smokeless powders 
 can be varied to suit any desired rate of explosion, 
 it falls naturally into the business of the powder 
 manufacturer to suit his productions to the need of 
 the guns, instead of expecting the guns to be made 
 to suit the powders. 
 
 By accepting the law of acceleration due to a 
 regularly diminishing pressure as being most simple 
 in all relationships, and especially for guns, it only 
 becomes necessary to provide an initial pressure 
 which should be double that of the mean pressure, 
 and this initial pressure gradually falls to zero, as 
 shown by the sloping line c, b in Fig. 2, or the curve 
 A, R in Figs. 3 5, 6 and 7. 
 
 Supposing all the charge to be exploded into 
 permanent gases before the shot commences to 
 
38 MODERN GUNS AND SMOKELESS POWDER. 
 
 move, then its initial pressure would rise far above 
 twice the average pressure, and it would fall ac- 
 cording to a curve approximating to a hyperbola 
 much like the expansion curve in a steam engine 
 indicator diagram. 
 
 Such a powder could never give a curve at all 
 approaching the sequence of pressures suggested as 
 a standard, but there is a way remaining open by 
 which this can be done, namely, by using a powder 
 that continues to burn all the time, and does not 
 complete its combustion until the shot is at the 
 point of leaving the muzzle. 
 
 It would seem best that this ideal powder should 
 have its rate of combustion controlled in some 
 degree by the pressure under which such combustion 
 occurs, and, just as a candle burns quickly under 
 ordinary pressure, and very slowly in compressed 
 air, so should the explosive burn quickly until the 
 space occupied by the cartridge reaches the intended 
 initial pressure, when the combustion is slowest, and 
 gains in rapidity as the pressure reduces during that 
 fraction of a second while the shot is travelling 
 in the bore. 
 
 By this means each foot length of the gun bears 
 its full proportionate share in resisting the forces 
 needed to propel a shot at its highest muzzle 
 velocity, till the limit of endurance is reached, and 
 we obtain the lightest possible gun for giving the 
 best results in firing. It may be said that these are 
 conclusions by no means new ; but it may well be 
 asked how many years have been necessary to find 
 
MODERN GUNS AND SMOKELESS POWDER. 39 
 
 them out, and how many costly failures have been 
 made to prove what these diagrams and simple 
 calculations show so clearly and so well. The 
 tabulated statements of modern gun practice show 
 that no recognised standard or orderly system yet 
 exists ; everything seems to be done haphazard, 
 and it is in the hope of doing some little towards 
 evolving order out of chaos, that this memorandum 
 has been compiled. 
 
 Note. — Recently a diagram has been published 
 by Captain Noble, contrasting the curves of pressure, 
 velocity, and time, ascertained from the same gun 
 when firing Pebble Powder, Amide, or Cordite. 
 These powders gave maximum pressures of i6"4 
 tons, 16 tons, and 14*4 tons respectively; and 
 corresponding muzzle velocities of 1839 feet, 2036 
 feet, and 2150 feet. 
 
 His curves, rearranged on the same principle as 
 Fig. 6, produce most instructive diagrams, and tend 
 still further to confirm the conclusions arrived at by 
 considerations drawn from the behaviour of the 
 38-ton gun tested under similar conditions. 
 
PART II. 
 
 MODERN EXPLOSIVES. 
 
 Modern explosives for purely military and naval 
 purposes may be classified under two heads, 
 namely — 
 
 (i.) Explosives for use in guns. 
 
 (2.) " High explosives," for charging mines, 
 filling shells, &c. 
 
 Up" to recent times, gunpowder stood alone under 
 the first heading, while all under the second heading 
 were too violent in their operation, and could only 
 be used for mines, torpedoes, &c. 
 
 Gunpowder represents a class of explosives, not 
 chemical compounds, but wherein the materials are 
 mixed in something like their combining propor- 
 tion ; and attempts to construct a new explosive 
 on this principle have not been very successful. 
 
 One mixture, known as " Amide " powder, or 
 " Chilworth special," has the sulphur of gunpowder 
 replaced by ammonium nitrate, and its explosion 
 gives a considerable increase of permanent gases, 
 with a corresponding rise in potential energy. 
 
 The diminished quantity of gritty solid particles, 
 grinding along the bore after an explosion, implies 
 
MODERN GUNS AND SMOKELESS POWDER. 4 1 
 
 a lessened erosive action from this, or indeed any 
 other powders convertible into permanent gases, in 
 contrast with gunpowder, and its 57 per cent, of 
 permanent solids ; and experiment fully confirms 
 this inference. 
 
 But there is a fatal objection to " Amide," and all 
 other powders containing ammonium nitrate as 
 their basis, because of its deliquescent character, an 
 objection which detracts from its value as an other- 
 wise useful ingredient of smokeless powders also. 
 
 One of the first high explosives discovered was 
 guncotton, and although many attempts were made 
 to adapt it to firearms, no satisfactory results ever 
 came from these experiments. 
 
 A variety of other explosives were tried, wherein 
 picric acid, nitrate of ammonia, or other compounds 
 containing nitrogen formed the basis, but their 
 chemical reactions were not until lately under 
 sufificiently reliable control, and the explosives acted 
 far too rapidly for use in guns. 
 
 Various forms of nitro-glycerine were equally 
 unsuccessful, and this powerful explosive had to 
 be mixed with infusorial earth under the name of 
 "dynamite," to render it manageable, and mode- 
 rately safe, even for blasting purposes in mines. 
 
 Curiously enough, however, this violent explo- 
 sive, when mixed — or more properly combined — 
 with some other violent explosives, actually has the 
 effect of producing a compound which is less violent 
 in its action than either ingredient alone ! 
 
 Modern chemistry, however, has now discovered 
 
42 MODERN GUNS AND SMOKELESS POWDER. 
 
 that the rate of combustion in some of these more 
 violent explosives can be reduced and so modified, 
 that their action is far less injurious to a gun than is 
 that of black gunpowder. Indeed, these modifica- 
 tions can be carried so far, that any desired rate of 
 explosion can be had. Thus a new and most impor- 
 tant series of combinations became available, 
 whereby the pressures can be arranged to suit any 
 requirements in a gun, and there remains no longer 
 any necessity for designing the gun to suit an ex- 
 cessive strong powder, instead of considering the 
 most serviceable construction, in regard to the 
 requirements of a gun. 
 
 Explosives to give little vapour, and that of a 
 character soluble in air, are of such universal 
 interest, that it is not surprising to find numerous 
 patents taken out for all kinds of changes, improve- 
 ments, or possibly retrogressions in the processes of 
 manufacture ; but it would be impossible to notice 
 these without extending this memorandum beyond 
 all reasonable' limits ; and perhaps it would be in- 
 vidious to select a few out of so many inventions, 
 some of which can hardly have been thoroughly 
 tested. There is, however, a consensus of opinion 
 that guncotton, in the form of tri-nitro-cellulose in 
 combination with nitro-glycerine, is the most 
 promising of all compounds for the production of a 
 suitable powder. Therefore most inventors have 
 turned their attention to improvements in the details 
 of its manufacture, particularly to the thorough 
 nitration of the whole mass and the avoidance of 
 
MODERN GUNS AND SMOKELESS POWDER. 43 
 
 any excessive production of the insufificiently nitrated 
 cotton or pulp, known to chemists as mono-nitro- 
 cellulose or di-nitro-cellulose. 
 
 The highest form of nitrification called tri-nitro- 
 cellulose, can only be produced in the presence of 
 undiluted nitric acid, so that when cotton or pulp is 
 added to the bath of nitric and sulphuric acids the 
 earlier portions become a pure tri-nitro-cellulose, 
 while later additions of cotton or pulp are found to 
 yield a certain proportion of the lower and inferior 
 qualities, owing to the nitric acid being diluted with 
 water produced during the nitrification of the first 
 instalments. 
 
 It is evident that an unstinted employment of 
 nitric acid would accomplish a complete nitrification 
 of the whole mass ; but it would do this at an 
 excessive cost, so the object of every inventor has 
 been to use acids weakened by partial use for pro- 
 ducing a confessedly imperfect nitro-cellulose which 
 can then be fortified by admixture with new supplies 
 of acids which, in their turn, can serve for the first 
 stage of the process. 
 
 The same general arrangements will apply to the 
 manufacture of nitro-glycerine where glycerine is 
 used instead of cotton or pulp, and goes through a 
 very analogous process. 
 
 Improvements in the process are made in another 
 direction, by cutting up and grinding cotton or 
 woody fibre into small fragments, so • that the acid 
 reactions do not become hindered in consequence of 
 the protection afforded to the fibres by the hard or 
 
44 MODERN GUNS AND SMOKELESS POWDER. 
 
 silicious skin in which they are generally enveloped. 
 In addition to this coating, a gum or essential oil is 
 present, and this is slow to dissolve, not always 
 being completely removed by the alkaline washings 
 to which fibres are subjected before the process of 
 nitrification is commenced. 
 
 The removal of these difificulties, partly chemical 
 and partly mechanical, are subjects of several patents 
 which are intended to produce a nitro-cellulose of 
 uniform composition, and ballistic qualities. 
 
 Strength of Various Explosives. — The strength of 
 various explosives exhibits great differences, and pro- 
 bably the most violent and dangerous of all known 
 to chemists is chloride of nitrogen ; but this substance 
 is so easily disintegrated that it is perfectly useless 
 for military purposes. Of all explosives based upon 
 the use of a nitro-cellulose, the gelatinised com- 
 pounds rank highest in their explosive qualities. 
 
 Then comes nitro-glycerine, followed in order by 
 guncotton, dynamite, picric acid compounds, melanite, 
 and gunpowder. 
 
 It may now be useful to give a short account of 
 some of these explosives, and the modes of their 
 manufacture. 
 
 Guncotton. QH^ 3 (NO,) O^. 
 
 A very important modern explosive is guncotton, 
 which is a nitro-cellulose obtained by steeping 
 thoroughly dried cotton in a mixture of strong nitric 
 
MODERN GUNS AND SMOKELESS POWDER. 45 
 
 and sulphuric acids. During the time when nitra- 
 tion is taking place, the sulphuric acid acts as an 
 absorbent of all free water, together with that which 
 is produced by the chemical reactions occurring dur- 
 ing the process. 
 
 The resulting product is washed in water and 
 alkalies, to remove all free remaining acids, and then 
 converted into pulp by revolving knives. 
 
 This process was adapted to the manufacture of 
 guncotton, by Sir Frederick Abel, F.R.S., Chemist 
 to the War Department, and he also arranged 
 hydraulic presses by which compressed guncotton 
 was sent out wet or dry, according to its intended 
 use ; dry guncotton burns rapidly in the open air, 
 with a bright flame making no smoke, but only a 
 thin vapour which dissolves at once in the air. 
 Wet guncotton is not readily fired, and can only 
 be exploded with a pistol and detonator. 
 
 Dry guncotton is not considered reliable in hot 
 climates, in consequence of the development of 
 nitrogen compounds, which cause spontaneous 
 decomposition and explosion. This danger, how- 
 ever, is removed by keeping it constantly wet, and 
 this is done in all magazines, whether in ships of 
 war or ashore. 
 
 For all this, guncotton remains the safest of all 
 high explosives, and it possesses the great advan- 
 tage of being uninjured by time or exposure to 
 damp unless it becomes mildewed. 
 
 Wood-pulp, or other vegetable substances, are 
 used instead of cotton for manufacturing the large 
 
46 MODERN GUNS AND SMOKELESS POWDER. 
 
 quantity of nitro-cellulose required for smokeless 
 powders. 
 
 Curious variations occur as to the rate of combus- 
 tion and other qualities in the explosive, when made 
 from different kinds of woody fibre, and very little is 
 understood as to the precise causes of such minor 
 variations. Before the manufacture of guncotton or 
 nitro-cellulose was thoroughly understood, several 
 very disastrous explosions occurred ; and although 
 in England the manufacture has now for many 
 years been carried on with perfect safety, yet 
 it does not seem as if sufficient precautions have 
 always been taken abroad, as disastrous explosions 
 are still occasionally reported. 
 
 Nitro-Glycerine. 
 
 Tri-Nitro-Cellulose = C3H3(N03)3. 
 
 This explosive was discovered by Sobrero in 1847, 
 and it is produced by adding glycerine, in small 
 quantities at a time, to a mixture of one volume 
 fuming nitric acid of a specific gravity about i"43, 
 and two volumes of the strongest sulphuric acid, of 
 a specific gravity about i '83. 
 
 Considerable heat arises during the mixture of 
 these acids, so that they have to be cooled, and kept 
 at from 40° to 90° Fahr. for the subsequent process. 
 
 Not until the acids are thoroughly cooled, is it 
 safe to add, little by little, about 12 per cent, of their 
 
MODERN GUNS AND SMOKELESS POWDER. 47 
 
 weight of syrupy glycerine. This mixture is con- 
 stantly stirred, and the great heat developed by the 
 chemical reactions must be absorbed by a coil of 
 water pipes, by ice, or by other means such as 
 freezing mixtures ; so that on no account shall the 
 temperature exceed about 105° Fahr. 
 
 This is the most dangerous part of the whole pro- 
 cess, for any excessive heat would cause a violent 
 explosion, with results disastrous in the extreme. 
 
 When further action ceases, the process is com- 
 pleted, and the nitro-glycerine floats over the surface. 
 
 The mixture is then poured by small quantities 
 at a time, accompanied by constant careful stirring, 
 into a bath of cold water. Although the nitro- 
 glycerine floats on the surface of the mixed acids, 
 its specific gravity is greater than water, in which it 
 is practically insoluble, as the oil sinks to the bottom 
 of its water-bath, and the upper layer of dilute acid 
 can be removed by decantation or by a syphon. 
 
 The chemical reactions which occur during the 
 formation of tri-nitro-cellulose, the most explosive 
 form of nitro-glycerine, are as follows : — 
 
 Glycerine (CjHaO,) + Nitric acid (3HNO3) = 
 Nitro-glycerine (C3H5(N03)3) + Water (3OH,). 
 
 Thus it will be seen that in the process of nitrifi- 
 cation the 3 parts of water forming its original 
 composition are replaced by 3 parts of nitric acid ; 
 and there remains over the residue of water which 
 is absorbed by the sulphuric acid. 
 
 The affinity of nitric acid for i part of the con- 
 
48 MODERN GUNS AND SMOKELESS POWDER. 
 
 stituents of nitro-glycerine is assisted by the affinity 
 of sulphuric acid for the other part, and this double 
 influence is necessary to effect the reactions above 
 described. 
 
 The nitro-glycerine is now washed again and 
 again in fresh water, to remove every trace of 
 remaining acid, and this process is continued until 
 blue litmus paper shows no change of colour. 
 
 Pure nitro-glycerine can be obtained by crystal- 
 lization from its solution in wood naphtha, but such 
 a refinement is never necessary when the explosive 
 is required for immediate use. Nitro-glycerine is a 
 yellowish oily liquid, having no smell, and a sweet 
 pungent taste. 
 
 It is so poisonous, that a tiny quantity placed on 
 the tongue produces a violent headache lasting for 
 many hours, cough, indigestion, and a general 
 disturbance of the nervous system. These effects 
 are doubtless produced from fine unconsumed 
 particles of nitro-glycerine, which are scattered 
 about after any explosion ; and these evils are 
 increased in mining operations, where the products 
 of explosion are unable to get quickly mixed with 
 large quantities of air. The asphyxia sometimes 
 produced by nitro-glycerine or dynamite poisoning 
 is probably due to, or accentuated by, volumes of 
 carbonic monoxide, which comes from the chemical 
 reaction. This dangerous gas is supposed to be 
 absorbed by the red corpuscles in blood, and never 
 discharged like oxygen ; consequently, these bodies 
 being saturated by one gas, cannot find room for 
 
MODERN GUNS AND SMOKELESS POWDER. 49 
 
 the vitalizing agent, and asphyxiation follows as a 
 matter of course. Nitro-glycerine is also readily 
 absorbed into the system through the skin when 
 handled, but, curiously enough, this peculiarity 
 ceases after a time. 
 
 This liquid has a specific gravity of i • 6, and 
 freezes solid at about 5° centigrade or 40° Fahrenheit, 
 and explodes at about 360° Fahrenheit. It burns in 
 the open air with a smoky flame, and can be readily 
 exploded by concussion, and when frozen it is par- 
 ticularly dangerous, as mere friction will cause a 
 disaster. 
 
 Another method has been patented for manu- 
 facturing nitro - glycerine, and it consists of a 
 mechanical process, worked by compressed air, by 
 which the acids and glycerine are made into a 
 spray, and mixed in a sort of injector, the ex- 
 pansion of the air producing a lowered tempera- 
 ture, which counteracts the increasing temperature 
 attending the mixture of acids and glycerine. 
 
 Nobets Dynamite, No. i of commerce, consists of 
 75 per cent nitro-glycerine mixed with 25 per cent. 
 of a very absorbent infusorial earth known as 
 " Kieselguhr" ; and Lithofracteur, another explosive, 
 consists of 55 per cent, of nitro-glycerine and other 
 substances in different proportions, all of which add 
 to its explosive character, and it contains only a 
 very small proportion of the inexploslve and incom- 
 bustible " Kieselguhr." Blasting gelatine is prac- 
 tically a stage in the manufacture of smokeless 
 powders, and it is composed of the soluble or 
 
50 MODERN GUNS AND SMOKELESS POWDER. 
 
 collodion form of guncotton dissolved in nitro-gly- 
 cerine. 
 
 In this curious chemical compound the nitro- 
 cellulose becomes gelatinised, while the nitro-gly- 
 cerine forms part of a more stable compound, and 
 one that practically serves as the basis for all those 
 smokeless powders which seem most likely to become 
 the permanent substitutes for ordinary gunpowder. 
 
 Smokeless Powders. 
 
 Numerous compounds have been brought out as 
 " Smokeless Powders," called in Germany " Smoke- 
 Feeble Powders," as none are really smokeless, and 
 their mode of manufacture has been surrounded by 
 much mystery. 
 
 The whole problem, however, is one of compara- 
 tively simple chemistry, and mechanical manipu- 
 lation, so that although the materials composing the 
 chief smokeless powders are well known, yet minor 
 details of manufacture are kept by various makers 
 as trade secrets, and such matters are somewhat 
 jealously guarded as they cannot be properly pro- 
 tected by patent. All smokeless powders are sup- 
 posed to have nitro-compounds, or picrates as a 
 base, but those most generally used are composed 
 of a compound containing nitro-cellulose and nitro- 
 glycerine. 
 
 The original " Nobel " powder is described as 
 
MODERN GUNS AND SMOKELESS POWDER. 5 I 
 
 being composed of lo parts by weight of camphor, 
 dissolved in 100 parts by weight of nitro-glycerine. 
 Then 200 parts by weight of benzole is added, and 
 50 parts of nitro-cotton pulp is steeped in the liquid. 
 
 The mixture is then warmed to evaporate the 
 benzole, which acts merely as a solvent, and the 
 resulting compound is passed between steam-heated 
 rollers, and the sheets so produced finally cut up 
 into small squares or other shapes as required. 
 
 It was, however, found that camphor was un- 
 reliable, and the composition has been completely 
 altered. It is rolled into thin sheets of a dark 
 colour, and cut into strips and grains. 
 
 Nitrate of Ammonia is used as a basis in other 
 smokeless powders, but it has the disadvantage of 
 being deliquescent, so that it has to be made up into 
 cartridges hermetically sealed, and these are con- 
 structed hollow, so as to provide an air chamber 
 which lessens the violence of explosion. 
 
 Various other substances, such as picric acid, 
 chloro-picrum, hydro-chlorate of ammonia, camphor 
 benzole, nitrate of ammonia, nitrate of soda, nitrated 
 carbolic acid, nitrate of potassium, hyposulphite of 
 soda, and other alkalies, and many other substances, 
 are used in the manufacture of smokeless powders 
 or high explosives ; but, so far as present experience 
 goes, those compounds which have blasting gelatine 
 as the first stage of their manufacture seem to meet 
 with most general favour. 
 
 E 2 
 
MODERN GUNS AND SMOKELESS POWDER. 
 
 Cordite. 
 
 This smokeless powder was invented by Sir 
 Frederick Abel, F.R.S., Chemist to the War 
 Department, in conjunction with Professor Dewar, 
 F.R.S., of the Royal Institution, London, and other 
 eminent chemists, and it has been made in con- 
 siderable quantities at the Government powder 
 factory at Waltham Abbey, and by the Chilworth 
 Company, and also in Germany. 
 
 The chief ingredient in its composition is gun- 
 cotton, or nitro-cellulose, and this is mixed with 
 nitro-glycerine, with the help of a solvent. 
 
 Other substances are added, whose function is to 
 tone down and determine the rate of combustion, so 
 as to fit the resulting explosive for use in guns. 
 
 When the ingredients have been thoroughly 
 mixed and incorporated (just as gunpowder is 
 incorporated) they become a pasty mass, which is 
 placed in a circular chamber having holes in its 
 lower end ; hydraulic pressure is applied, and the 
 mass is squirted in the form of thick jelly into 
 strings, whose diameter is determined by that of the 
 holes. 
 
 These strings are collected upon a reel, rapidly 
 dried by steam, and finished by being cut to the 
 length of the intended cartridge, tied together 
 into bundles, and placed into the cartridges ; all 
 these operations being performed by self-acting 
 machinery. 
 
MODERN GUNS AND SMOKELESS POWDER. 53 
 
 The rate at which Cordite explodes depends in a 
 great measure upon its diameter, and thus one 
 uniform composition may give great varieties of 
 pressure according to its mechanical state alone, and 
 this is a very important consideration. 
 
 The effect of Cordite in accelerating the muzzle 
 velocity of a shot is well shown by the following 
 table, supplied by the Maxim Nordenfelt Company, 
 being experiments made on their own guns. 
 
 Descrip- 
 tion of 
 Gun. 
 
 Bore. 
 
 Projec- 
 tile. 
 
 Black Powder. 
 
 Cordite. 
 
 Calculations, Mean 
 Pressure. 
 
 Charge. 
 
 M. V. 
 
 Charge. 
 
 M. v. 
 
 Black 
 Piiwder. 
 
 Cordite. 
 
 14-Pr. 
 3-Pr. . 
 
 inches. 
 3 
 I-8S 
 
 lbs. 
 3"3 
 
 lbs. ozs. 
 
 7 2 
 I 8 
 
 feet. 
 2100 
 
 1920 
 
 lbs. ozs. 
 2 12 
 
 12 
 
 feet. 
 
 2455 
 
 2284 
 
 7-309 
 5.281 
 
 9' 102 
 7-486 
 
 In both cases higher results are secured by -J and 
 ^, the weight of explosive respectively, as compared 
 with black or brown gunpowders. 
 
 The initial pressures were not ascertained, but 
 they will doubtless be less in either case than the 
 corresponding pressures with black gunpowder. 
 
 In the 15th Annual Report of H.M. Inspectors 
 of Explosives for 1890, page 80, the following 
 experiments are described. They were undertaken 
 to determine the liability of Cordite to explode en 
 masse, on October 21, 1890, and were carried out in 
 the presence of the Director-General of Ordnance 
 
54 MODERN GUNS AND SMOKELESS POWDER. 
 
 Factories, H.M. Chief Inspector of Explosives, and 
 Other officers : — 
 
 "(i) ICO lbs. of coarse Cordite (3 inches in 
 diameter and 14 inches in length) packed in a 
 service box (measuring 2 feet 3 inches by 14 feet 6 
 inches by 7 feet 9 inches deep, and having i| inch 
 sides and i inch top and bottom), was attempted to 
 be ignited by means of a tube and small priming 
 charge of guncotton. But the Cordite failed to 
 ignite. 
 
 " (2) Repetition of above, but using a small 
 priming charge of fine Cordite ('05 inches diameter 
 and 1 1 inches long). The whole mass burst im- 
 mediately into flame, and burned with great and 
 rapid energy and brilliancy. The lid was removed 
 by the energy of the outburst, the screws being 
 drawn, and those on one end bent. The mass 
 burned for about three seconds, and the light was 
 of the most brilliant character. 
 
 " (3) Repetition of No. i, with same result — no 
 ignition. 
 
 " (4) Repetition of No. 2. The Cordite ignited 
 and burned with great brilliancy and a gush of 
 bright flame for about 7| seconds. The lid of the 
 box was forced off (as in No. 2), and the screws 
 were drawn, and in some cases bent. 
 
 "(5) A service case (of dimensions previously 
 given) containing 100 lbs. of the fine Cordite was 
 surrounded by wood and shavings, which were set 
 fire to. The bonfire burned for 15 minutes, when 
 the Cordite in the case ignited, and burned with a 
 
MODERN GUNS AND SMOKELESS POWDER. 55 
 
 great rush of most brilliant flame for about four or 
 five seconds. Some small pieces of the burnt wood 
 were then thrown to a distance of about 12 yards. 
 An end of the box was forced out. One side was 
 partially forced out. 
 
 " (6) Repetition of No. 5, but using fine instead 
 of coarse Cordite. After the bonfire had been 
 burning for seven minutes, the Cordite caught and 
 went off with a dull, muffled burst which nearly 
 amounted to a mild explosion. 
 
 "There was, however, certainly nothing ap- 
 proaching a violent explosion, as was shown by 
 only one side of the box being displaced. 
 
 " (7) Six service boxes, each containing 100 lbs. 
 of thick Cordite, were placed together, five on end 
 and one on the top ; the centre box (in lower tier) 
 was set fire to., It burned about six seconds, and 
 upset the side boxes, but it did not throw off the 
 top box ; only the box which was ignited caught 
 fire. 
 
 " (8) Five service boxes, each containing 100 lbs. 
 of thick Cordite (i.e. those which remained from 
 the last experiment), were placed in a pile, two, two, 
 and one, breaking joint, and surrounded by wood 
 and shavings, which were set fire to. 
 
 Mins. 
 
 Sees 
 
 After 15 
 
 
 
 „ IS 
 
 7 
 
 „ IS 
 
 14 
 
 „ IS 
 
 21 
 
 » IS 
 
 28 
 
 I box of Cordite ignited. 
 ^ >j J) 
 
 I fi JJ 
 
 * 1) jj 
 
56 MODERN GUNS AND SMOKELESS POWDER. 
 
 "Each box burned with a bright rush and burst 
 of flame, but without explosion. The boxes were 
 not broken up, and no fragments of the bonfire 
 were projected beyond about lo paces. 
 
 " (9) A pile of eight service boxes, containing 
 each about 75 lbs. (total 600 lbs.) of Cordite, was 
 surrounded with wood and shavings, which were set 
 fire to. The top box had a hole in it, which was 
 roughly plugged, and this apparently caught fire 
 and burned away non-explosively at i minute 10 
 seconds after the bonfire had been ignited. The 
 other boxes ignited in succession and burned away 
 non-explosively. The times were as follows : — 
 
 
 
 Mins. 
 
 Sees. 
 
 
 
 Mins. 
 
 Sees. 
 
 I St box . 
 
 . 
 
 I 
 
 10 
 
 Sth box . 
 
 * 
 
 . 17 
 
 25 
 
 2nd „ . 
 
 . 
 
 I 
 
 IS 
 
 6th „ . 
 
 . 
 
 . 18 
 
 37 
 
 3rd » • 
 
 . 
 
 . 2 
 
 2 
 
 7th „ . 
 
 . 
 
 . 21 
 
 31 
 
 4th „ . 
 
 . 
 
 • 5 
 
 45 
 
 8th „ . 
 
 . 
 
 . 21 
 
 33" 
 
 Satisfactory results are also given by Cordite as 
 used in rifles, and this may be seen from the follow- 
 ing recent letter referring to results obtained from 
 firing in June 1892. This letter is a reply to an 
 inquiry as to whether the new smokeless powder, 
 " Cordite," is giving satisfaction : — = 
 
 Dear Sir, — In reference to your inquiry as to 
 whether " Cordite " powder is giving satisfactory 
 results, I am desired by Mr. Stanhope to inform 
 you that the military authorities are well satisfied 
 with our new smokeless powder. The following 
 
MODERN GUNS AND SMOKELESS POWDER. 
 
 57 
 
 table bears testimony to the reliable quality of 
 " Cordite " powder. — I am", dear Sir, yours truly, 
 
 G. Fleetwood Wilson. 
 
 War Office. 
 
 Aldershot Division. 
 
 Return of "303 Cordite ammunition, showing the number of 
 rounds expended, and number of miss-fires that occurred during 
 the month of June, 1892 
 
 Corps, 
 ist S.W. Borderers 
 I St Durham L.I. . 
 2nd Leinster . 
 
 I St Scottish Rifles 
 ist Northampton. 
 2nd Welsh Regimen 
 
 ist R. Lancaster 
 ist R. Warwick . 
 1st Lincoln . 
 2nd S. Stafford . 
 
 Total 
 
 MisS' 
 
 No, 
 
 of Rounds expended. Miss-fires. 
 
 42,300 
 30,731 
 25,322 
 
 19,140 
 62,760 
 10,949 
 
 21,493 
 38,594 
 26, 61 
 
 25,560 
 
 303,110 
 fires "60 per 1000. 
 
 17 
 
 19 
 
 8 
 
 4 
 43 
 13 
 
 29 
 
 Nil 
 
 47 
 4 
 
 184 
 
 The following extracts from a paper read before 
 the Royal United Service Institution, in July 1891, 
 by Lieutenant-Colonel G. V, Fosbery places the 
 views of a thoroughly competent expert in a concise 
 and telling form : — 
 
 "At present, so far as is known to me, we are 
 still in search of the ideal explosive ; one, in fact, 
 which shall pack into the smallest possible space, 
 
58 MODERN GUNS AND SMOKELESS POWDER. 
 
 develop the utmost energy, and keep indefinitely 
 under all possible circumstances, and until we have 
 found this, or at all events some reasonable ap- 
 proach to it, we cannot with a light heart adopt, as 
 our Continental friends have done, a smokeless 
 powder for the use of our troops. Gunpowder we 
 know all about, it is a good honest mixture, and, 
 sorely tried as it frequently is ashore and afloat, it 
 may be always reckoned on to do its duty so long 
 as we keep it dry. But when we come to high 
 explosives, specially when these are chemical com- 
 pounds, and from their very nature more or less 
 unstable compounds at that — we, more than any 
 other people, must exercise the utmost precaution 
 in their general adoption, arid be sure that neither 
 the damps and heats of India, the salt air in our 
 naval magazines, nor the cold of Canadian winters, 
 will set thfese treacherous substances fermenting, 
 decomposing or exploding. Hitherto, perhaps, on 
 the whole Professor Abel's powder. Cordite, has 
 shown the best all-round qualities, and bids fair for 
 final selection." 
 
 Various Smokeless Powders. 
 
 Besides Cordite and smokeless powders, many 
 other kinds are used : " Poudre B." (Vielle Poudre), 
 invented by M. Vielle, is used for the Lebel rifle, 
 
MODERN GUNS AND SMOKELESS POWDER. 
 
 59 
 
 and it emits a thin bluish smoke, and gives a com- 
 paratively feeble report. " Melanite " is the name 
 given to a high explosive used for loading shells, 
 and very little is known as to its composition or 
 capabilities ; originally it was so unreliable that 
 various alterations and improvements were made, 
 and now it is considered to be perfectly safe. 
 
 Other powders called " Ballastite," and " Chil- 
 worth Special," or " Amide Powder, are used for 
 military purposes ; the latter is made up in her- 
 metically-sealed cases, owing to the deliquescent 
 qualities of one of its ingredients, nitrate of ammonia. 
 
 Table 4 gives a series of interesting results, com- 
 paring together the effects of black gun-powder 
 and brown gunpowder, with " Chilworth Special," in 
 a manner which clearly shows the chief advantages 
 of the new kind of powder, 
 
 TABLE 4. 
 
 Calibre. 
 
 Charge. 
 
 Powder, 
 
 Projec- 
 tile. 
 
 Muzzle 
 Velocity. 
 
 Chamber 
 Pressure. 
 
 inches. 
 4*725 ' 
 
 lbs. 
 12 
 
 12 
 
 Black Powder 
 C, special 
 
 lbs. 
 45 
 
 45 
 
 F. S. 
 1850' 
 
 2250' 
 
 tons. 
 15 
 
 15-5 
 
 j 
 
 60 
 
 Brown Powder 
 
 100 
 
 2260' 
 
 15 
 
 6 . . j 
 
 38 
 
 C'., special 
 
 100 
 
 2340' 
 
 16-5 
 
 Much the same character of results arise from a 
 comparison between Cordite, or any other smokeless 
 
6o MODERN GUNS AND SMOKELESS POWDER. 
 
 powder, with black or brown gunpowder ; and the 
 table shows how, in one case, an increase of chamber 
 pressure of half a ton extends the muzzle velocity 
 400 feet per second. That is, 3-J per cent, extra initial 
 pressure gains 21 per cent, increased velocity. 
 
 Or taking the 6-inch gun, a charge of " Chil worth 
 Special," reduced by 22 lbs. as compared with brown 
 powder, gives i • 5 tons extra initial pressure, and 80 
 feet per second increased velocity. 
 
 All these considerations lead to the conclusions 
 pointed out in the first part of this memorandum ; 
 namely, that when the gun has been constructed in 
 the strongest manner there remains another problem 
 to be solved. 
 
 This problem is the combining of a smokeless 
 powder in such proportions as shall give the highest 
 average pressure, conjoined with such slow burning, 
 as shall not needlessly strain the materials of which 
 the gun is constructed. 
 
 Another powder, known commercially under the 
 name " Smokeless Powder," has been manufactured 
 since 1884 for sporting purposes by the Smokeless 
 Powder Company, and more recently they have 
 taken up the manufacture of two kinds for purely 
 military purposes. 
 
 One (SR) is intended for the Martini-Henry rifles 
 of "420 and '450 inches bore, while the other class, 
 called " Rifleite," is for the magazine rifles of "303 
 inches bore, and for quick-firing guns. 
 
 There has been sufficient experience of Cordite and 
 this smokeless powder to be sure of their safety and 
 
MODERN GUNS AND SMOKELESS POWDER. 6 1 
 
 Stability in this country, so that both may be con- 
 sidered out of that early experimental stage through 
 which all new inventions must pass. Experience is 
 now being gained with the use of these powders in 
 India and Canada, and before long it will be known 
 whether they are in any way injuriously affected by 
 hotter and colder climatic conditions than prevail 
 in England. 
 
 For heavy artillery the rifleite composition, with 
 certain modifications, might be advantageously em- 
 ployed, but the powder must be made to assume a 
 different form. 
 
 Its grains must be enlarged in the same manner 
 as gunpowder is treated at present, to lessen the 
 rapidity of explosion, and the magnitude of its 
 cubes must be proportioned to the calibre of the 
 gun. 
 
 This conclusion is, however, somewhat of a 
 theoretical kind, as no heavy artillery has yet been 
 supplied with a powder answering this description ; 
 and, indeed, it is quite possible that some of the 
 compounds in which picric acid shares a prominent 
 part may turn out the best for heavy guns. 
 
 Comparison between the Quantity of Gun- 
 powder OR Smokeless Powder for loading 
 Cartridges. 
 
 One ton of this smokeless powder serves to load 
 360,000 Martini-Henry cartridges, and this is rather 
 more than double the number that can be loaded 
 
62 MODERN GUNS AND SMOKELESS POWDER. 
 
 from one ton of ordinary black gunpowder, conse- 
 quently one million Martini- Henry cartridges, loaded 
 with smokeless powder, weigh about three tons less 
 than the same number loaded with gunpowder ; and 
 the saving, even in transport alone, becomes very 
 important. 
 
PART III. 
 
 MACHINERY REQUIRED FOR MANU- 
 FACTURING MODERN EXPLOSIVES. 
 
 Machinery required for the manufacture of 
 smokeless powder resembles, in some respect, that 
 which is in use for the manufacture of gunpowder. 
 
 If it be decided to manufacture the class of 
 smokeless powder called Cordite, which, in the 
 author's opinion, is the best of all smokeless 
 powders, then the machinery required to cover the 
 whole of the process should embrace the follow- 
 ing :— 
 
 1. A chemical plant for the manufacture of those 
 acids and chemicals necessary for the production 
 of guncotton. 
 
 2. A complete plant for the manufacture of gun- 
 cotton, and this plant, while providing the material 
 which forms the basis of Cordite, is also useful for 
 the production of guncotton for various naval and 
 military purposes, such as for charging fixed 
 buoyant or floating mines, charging torpedoes, &c. 
 
 3. A plant for the manufacture of Cordite for use 
 in Martini-Henry or Magazine rifles, and for 
 Maxim, Nordenfelt or Gatling guns, and for ord- 
 nance generally, up to the largest calibres. 
 
64 MODERN GUNS AND SMOKELESS POWDER. 
 
 General Arrangements for a Factory. 
 
 Although the processes involved in the manu- 
 facture of smokeless powders are generally less 
 dangerous than those for gunpowder, yet as some 
 of these require a tolerably uniform temperature, and 
 on no account may be carried out in excessive heat, 
 it is desirable to locate the works in a part of the 
 country where uniform climatic conditions most nearly 
 prevail ; also, as the processes should be carried on 
 in a scattered manner, a factory for making any kind 
 of explosive necessarily occupies a considerable area 
 of grounds, so that the processes can be carried on 
 in comparatively small and separated buildings, set 
 at least 40 yards or metres apart. In case any one 
 building should explode, it neither destroys the 
 whole factory, nor causes any serious diminution in 
 the quantity turned out. The buildings should have 
 thick walls, with double roofs, and be protected 
 from the direct rays of sunshine, so that on no 
 account shall they become too hot. 
 
 As an additional security to protect the factory 
 from the effects of a lateral explosion, it is usual 
 to surround these buildings, where the more danger- 
 ous processes are carried on, with earthen embank- 
 ments, so that the main force of any explosion shall 
 be expended upwards, causing a comparatively small 
 lateral disturbance, which might otherwise involve 
 the destruction of adjoining buildings by concussion, 
 whenever the contents of one of them meet with 
 disaster. 
 
MODERN GUNS AND SMOKELESS POWDER. 65 
 
 For similar reasons, the incorporating or kneading 
 mills adjoining the engine-house should be sepa- 
 rated from it by a strong wall, and the general 
 machinery should be scattered in detachments over 
 the ground. 
 
 Thus it will be seen that a factory of this class 
 should not be erected near a town, although it should 
 be in a situation where adequate military protection 
 can be provided. 
 
 Such considerations as these scarcely come within 
 the scope of this memorandum, yet they belong to 
 the subject, and it may further be remarked that 
 powder mills should not be placed too near a navi- 
 gable river, where they might be bombarded by a 
 hostile fleet, nor too near to the frontier of any 
 foreign power, whose first object after, or perhaps 
 before, a declaration of war, would be to seize the 
 factory, and so paralyze the national defences. 
 
 Water-carriage and Power. 
 
 The most desirable situation is a level country, 
 where canals can be used to convey away the 
 explosives when manufactured ; or to move them 
 from place to place ; and if there were a fall of 
 water, the canals would be at two levels, and it 
 would be cheaper and better to drive the works by 
 turbines, than to find coal for steam-engines. 
 
 Powder mills employ water-power largely, and a 
 canal is generally made leading to every separate 
 building where power is required ; the canal is raised 
 
66 MODERN GUNS AND SMOKELESS POWDER. 
 
 above the surrounding country, and serves to carry 
 boats for transferring the powder from one place to 
 another. 
 
 Temperatures. 
 
 Many chemical processes are most successfully 
 carried out within comparatively narrow ranges of 
 temperature, and this is of the utmost consequence 
 in the manufacture of guncotton, nitro-cellulose, or 
 nitro-glycerine, as neglect of this precaution has 
 produced disastrous results. 
 
 This being so, it would be necessary to arrange 
 means for warming or cooling the buildings, 
 wherever the climate is subject to considerable 
 variations. 
 
 Warming can be accomplished by laying hot- 
 water pipes wherever required, and these could be 
 heated by steam pipes carried underground, or less 
 safely by furnaces placed at a distance from the 
 powder building. 
 
 But for cooling purposes nothing lean be better 
 designed than engines driven by compressed air, for, 
 on the exhaust being discharged into any room, 
 it at once expands, and serves as an excellent and 
 cooling medium. 
 
 Lighting the Works. 
 
 Oil Lamps. 
 
 Oil lamps placed outside windows of the various 
 buildings have long been used for powder mills, and 
 
MODERN GUNS AND SMOKELESS POWDER. 67 
 
 could easily be applied for lighting up the several 
 buildings of a smokeless powder factory, but it is 
 worth consideration, whether this simple arrange- 
 ment might not be replaced by another system, 
 namely, electric light. 
 
 The greatest disadvantage attending the use of 
 electricity, apart from its extra cost, would be the 
 necessity of having specially-trained men to look 
 after the dynamos, whereas any labourer would be 
 able to manage lamps. 
 
 Electric Lighting. 
 
 Machinery for the production of electricity needs 
 to be of very high class character, and is somewhat 
 liable to the risk of becoming damaged, so that to 
 avoid any stoppage it ought to be provided in 
 duplicate. 
 
 If one dynamo or engine should happen to be out 
 of order, then the chances are that the other will be 
 in a position to provide all the light and power 
 required. 
 
 Two such engines and two dynamos might be set 
 up in a special department of the buildings con- 
 taining the main engine ; and as there can be no 
 necessity for extraordinary economy in space, the 
 engines and dynamos might advantageously be 
 separate, and so arranged that either engine could 
 drive either dynamo by a belt from a countershaft 
 common to all. 
 
 The electric current could be conveyed by wires 
 
 F 2 
 
68 MODERN GUNS AND SMOKELESS POWDER. 
 
 on ordinary telegraph poles for arc or incandescent 
 lights, for lighting up the whole establishment at 
 night, and a current might even be provided to drive 
 machinery in isolated buildings where power will be 
 required, instead of water-power or compressed air. 
 
 In all electric light installations, it is usual to pro- 
 vide a reserve or store of current, in storage batter- 
 ies, and this is a commendable practice. The main 
 current is transmitted directly from the dynamos to 
 the lights, and any overplus passes into the storage 
 batteries ; or, if it should be more convenient, the 
 batteries can be charged during such times as there 
 is no demand for light. 
 
 A current can always be taken from these storage 
 batteries, so that even if the engines are standing, 
 any building can be lighted up in a moment by the 
 night watchman. If electric motors should be used 
 for driving isolated machinery, they can be worked 
 from storage batteries without there being anything 
 else going on in the factory. 
 
 ■Electric lighting and transmission of power may 
 thus be combined, and as both systems have now 
 reached a stage of practical success, there is nothing 
 of an experimental character in their application to 
 a powder factory, unless, perhaps, as to their safety 
 in such an application. 
 
 Compressed Air-power. 
 
 Should there be no water-power available, the 
 next best method for driving machinery in isolated 
 
MODERN GUNS AND SMOKELESS POWDER. 69 
 
 buildings would be compressed air, which is now 
 successfully used for driving tram-cars, and machinery 
 of many kinds, by Rigg's Revolving Engine, which 
 works noiselessly, and is not subject to the ports 
 being choked by ice produced from the expansion 
 of damp compressed air. Compressed to about 8 or 
 10 atmospheres, it travels in pipes underground, 
 and is about the cleanest and most useful power 
 extant. 
 
 Turbines ai e often used for driving air-compressing 
 pumps, and power so obtained can be transmitted 
 for long distances with cheapness and efficiency. 
 
 Transmission of Power. 
 
 It frequently happens that water-power can be 
 obtained at some distance from a locality convenient 
 for the erection of a factory, and in such cases the 
 question of its transmission is brought into prominent 
 notice. 
 
 There are four systems by which this can be done. 
 
 1. Compressed air, carried in pipes. 
 
 2. Hydraulic pressure, also carried in pipes. 
 
 3. Wire ropes and pulleys. 
 
 4. Electricity, conveyed by wires. 
 
 (i.) — Compressed Air has been employed to a 
 very great extent for mining operations where the 
 water-power obtained through a turbine is used to 
 drive air-compressing machinery. This pressure 
 can be conveyed very long distances through pipes. 
 
yo MODERN GUNS AND SMOKELESS POWDER. 
 
 and at but trifling loss from friction ; and if the air 
 can be heated before being used to drive a motor, 
 there is no better system extant for obtaining a 
 higher return in power for the heat expended. 
 
 (2.) — Hydraulic Pressure is most extensively 
 used for driving isolated machinery, such as cranes 
 or capstans in docks. A pressure, usually of about 
 700 lbs, per square inch, representing an equivalent 
 head of 1600 feet, is transmitted through cast-iron 
 or steel pipes from the pumping station, to any 
 place where lock gates, or bridges, cranes, or cap- 
 stans have to be worked. Very little loss of 
 pressure occurs when these pipes are of sufficient 
 capacity, but the engines generally used consume as 
 much water when running empty as when fully 
 loaded. 
 
 Such extravagance with steam would never be 
 tolerated by any scientific engineer ; but it is only 
 quite recently that hydraulic engines have been 
 provided with a governor which alters the stroke, 
 and so regulates the supply of water according to 
 the demand for power. 
 
 (3.) — Telo-Dynamic Transmission of power by 
 wire ropes had its origin and most extended appli- 
 cation in Germany and Switzerland. Owing to the 
 great tensile strength of steel wire rope, and the 
 high velocity at which it can be driven over large 
 pulleys, very considerable amounts of power are 
 conveyed long distances over hills and valleys, for 
 
MODERN GUNS AND SMOKELESS POWDER. /I 
 
 many years past ; but the cost of maintenance is 
 extremely high, and the system seems gradually 
 being displaced by electric transmission. 
 
 (4. ) — Electric Transmission. Dynamos driven by 
 turbines or hydraulic engines are used for trans- 
 mitting electric currents of high potential to drive 
 other dynamos arranged as motors, at long distances 
 from the source of power. 
 
 It is found that practically the same quantity of 
 electricity can be driven through a copper wire of 
 any given sectional area, however high may be its 
 pressure or voltage, so it becomes manifest that the 
 first cost is lessened by using the highest workable 
 pressure. 
 
 This consideration has gone so far in many cases 
 as to render contact with the wires fatal to the life 
 of men and horses, so that there is some doubt as to 
 the general advisability of using electricity in the 
 only form through which its economical applicability 
 for long distance transmission is available, and it 
 cannot be used at all in situations where the insulated 
 wires come in contact with water. 
 
 Comparisons. For very long distances, hydraulic 
 pressure and telo-dynamic transmission are not so 
 desirable as compressed air or electricity, so that the 
 choice remains with these two. 
 
 If electricity be used for lighting purposes, the 
 same staff might attend to dynamos for the trans- 
 
72 MODERN GUNS AND SMOKELESS POWDER. 
 
 mission of power; but by taking everything into 
 consideration it would appear that compressed air 
 stands before all its rivals. This is not only because 
 of its first cost, but because its maintenance is less 
 expensive. 
 
 The economy of transmission is great, though 
 really where ample water-power exists, this seems a 
 minor consideration, while its safety and durability 
 are far beyond that of the delicate and sensitive 
 machinery required for electrical purposes. More- 
 over, it requires trained electricians to look after 
 dynamos, while any engineer can do all that is 
 required to keep compressed-air machinery in work- 
 ing order. 
 
PART IV. 
 
 FACTORY FOR GUNCOTTON, NITRO- 
 GLYCERINE, AND SMOKELESS 
 POWDERS. 
 
 In order to fix the ideas in connection with the 
 manufacture of smokeless powders, it will be well to 
 assume a certain class of powder and minimum pro- 
 duction per annum. 
 
 Such an establishment may further be assumed, 
 capable of making smokeless rifle powders suitable 
 for Martini- Henry rifles of -420" bore, such as the 
 SR of the Smokeless Powder Company, and also 
 making a powder suitable for the new magazine 
 rifle of • 303" bore, like the rifleite produced by the 
 same company. 
 
 The object of any manufacture during the present 
 transition time would be to make a powder that can 
 be used with the existing vast stock of large-bore 
 rifles, as the full benefits expected from the new 
 powders cannot be attained, except with rifles of 
 smaller bore and machine guns, while heavy artillery 
 must wait for reconstruction, and use a powder in the 
 meantime suited to its present capabilities. But a 
 
74 MODERN GUNS AND SMOKELESS POWDER. 
 
 smokeless powder for the existing heavy artillery- 
 must be made for the guns in stock, and the great 
 variety existing makes the problem one which can- 
 not be solved without knowing the armament of any 
 particular nation that may be considering the erec- 
 tion of a factory for themselves. The materials 
 required for making a powder for rifles, machine- 
 guns, or heavy guns, are practically the same, 
 differences being less in chemical composition than 
 in the size of grain (or diameter of rod, if " Cordite " 
 be the powder intended). 
 
 It will be easy to understand that a powder for 
 pistols, for example, must burn more quickly than 
 one for rifles, and a powder for heavy guns must 
 burn more slowly than a powder for rifles. 
 
 If, for example, it be assumed that a factory has 
 to be erected capable of an annual production of 
 about 200 tons (400,000 pounds), half the quantity 
 being for powder suited to the Martini-Henry '450" 
 bore, while the other half would be adapted for the 
 new magazine rifle of • 303" bore, or machine-guns ; 
 then as 200 tons of smokeless powder would load 
 about 71 million cartridges, that is, about 200 rounds 
 for an army of 350,000 soldiers, such an army would 
 use the whole 200 tons produced by the factory 
 in one year, leaving nothing in reserve. 
 
 The value of 200 tons in England would be 
 about ^120,000, calculating the smokeless powder 
 as being worth ^600 per ton, besides the cost of 
 carriage ; so that by setting up a factory abroad, 
 the cost of building the factory, acquiring the 
 
MODERN GUNS AND SMOKELESS POWDER. 75 
 
 process, and purchasing the machinery, would very 
 soon repay itself. 
 
 But, after all, the cost of powder is small in 
 comparison with that of new rifles, which any nation 
 adopting the magazine rifle would have to pay. 
 This cost would vary from £4. to ^5 each rifle, 
 or about ^1,200,000, to ;^ 1,500, 000 for 300,000 
 rifles, whether made in its own arsenal, or purchased 
 from abroad. 
 
 In order to manufacture a smokeless powder, a 
 factory of three departments would be required : 
 one for making guncotton, another department for 
 making nitro-glycerine, and a third department 
 devoted to making the " Cordite," or other smoke- 
 less powder. 
 
 Machinery for making Guncotton. 
 
 The materials required for making guncotton are 
 simply cotton, or other form of woody fibre, also 
 concentrated nitric and sulphuric acids, in the pro- 
 portions one nitric acid to two sulphuric acid ; 
 the latter acid taking no further part in the chemical 
 reactions than acting as an absorbent of any free 
 moisture, and such water as may be produced during 
 nitrification of the cellulose. 
 
 The cotton has to be thoroughly dried in the first 
 instance, and this is accomplished by vertical steam- 
 jacketted cylinders, through which a current of air 
 is drawn to carry off the watery vapour. This 
 
76 MODERN GUNS AND SMOKELESS POWDER. 
 
 apparatus was designed by the writer for the Gun- 
 cotton Works at Stowmarket, and it is found so 
 effective that the cotton reaches a condition of such 
 absolute dryness, that its weight increases rapidly 
 by moisture being absorbed from the atmosphere, 
 and it must therefore be kept in closed vessels. 
 
 The next operation is to immerse the dried cotton 
 into a bath of nitric and sulphuric acids, and a hood 
 is placed over this earthenware bath, and a steam- 
 jet provided to carry off the acid fumes which arise 
 during the process. 
 
 After the cotton has laid a sufficient time in its 
 acid bath, it is most thoroughly washed ; and unless 
 this process is effectually done, there is considerable 
 risk of spontaneous decomposition and explosion, on 
 exposure to heat and light. 
 
 This effect arises from the decomposition of 
 resinous or fatty substances retained within the 
 cotton fibre, and the spontaneous decomposition 
 leads to the development of nitrogen acids and the 
 risk of explosion. Under Sir Frederick Abel's 
 system for manufacturing guncotton, the cotton is 
 next taken from the acid bath to a pulping machine 
 similar to the arrangement employed by paper- 
 makers, and it is there most thoroughly disinte- 
 grated and washed. Its appearance becomes ex- 
 actly that of paper pulp, and it is treated in a similar 
 manner, being filtered and afterwards compressed in 
 a powerful hydraulic press. 
 
 It is compressed into cakes or beads which can 
 be strung together, or into any other form desired. 
 
MODERN GUNS AND SMOKELESS POWDER. ']'] 
 
 It is not readily exploded in a wet state, except 
 through the intervention of a pistol and detonator, 
 and ranking as it does with violent explosives, it is 
 remarkably free from danger, and very safe to 
 handle. 
 
 Various substitutes have been proposed and used 
 instead of cotton for the manufacture of nitro- 
 cellulose, namely, paper, straw-pulp, wood-pulp, &c. 
 Some of these require from twelve to twenty hours' 
 immersion in the nitro-sulphuric bath to complete 
 their chemical transformation. 
 
 They also give slight differences in the resulting 
 explosive produced, and the choice of the kind of 
 cellulose forms one of the usual trade secrets 
 
 Appliances for manufacturing Nitro- 
 Glycerine. 
 
 Nitro-glycerine is made by mixing glycerine, in 
 small quantities at a time, with concentrated nitric 
 and sulphuric acids, in the manner described on 
 page 43, and so far it corresponds exactly with the 
 manufacture of guncotton. 
 
 During the process of nitration, the bath must be 
 kept cool by a coil of piping, through which a 
 current of cold water is flowing ; great care and 
 attention is required during the preparation of this 
 dangerous compound, and the temperature must 
 
78 MODERN GUNS AND SMOKELESS POWDER. 
 
 be carefully watched, for if it rises too high, there 
 is more than a risk of an explosion of a most 
 disastrous character. 
 
 But little machinery, from an engineering point 
 of view, is required for the manufacture of nitro- 
 glycerine, and only such simple appliances as 
 suffice for the early stages of guncotton, for the 
 process has more connection with chemistry than 
 with engineering. 
 
 Water-supply. — As a liberal supply of cold water 
 is needed in a nitro-glycerine factory, pumping 
 machinery must be provided, unless there be a 
 natural head of pressure available. 
 
 Compressed Air is found the most convenient 
 agent for mixing the acids and aiding the process 
 of nitrification, and it requires special pumping 
 machinery driven by steam or water-power for its 
 production. 
 
 Heating Apparatus. — Then, as temperature plays 
 so important a part in this manufacturing process, it 
 is essential to provide a heating apparatus for 
 maintaining the buildings above the comparatively 
 high freezing point of the explosive oil. 
 
 Such simple heating apparatus would consist of a 
 furnace, and boiler fixed at some distance from the 
 nitrating house, and protected from it by earthen 
 embankments. 
 
 After this adjunctive machinery has been provided, 
 the actual apparatus required for manufacturing 
 the oil itself is very simple. Each mixing vessel 
 bears considerable resemblance to a still, and one 
 
MODERN GUNS AND SMOKELESS POWDER. 79 
 
 apparatus consists of a vessel made of thick lead, 
 containing several thick coils of the same metal, 
 through which a current of cold water is conveyed 
 for the purpose of keeping down the high tempera- 
 tures resulting from the addition of glycerine to the 
 mixed acids. Each leaden vessel stands by itself, 
 clear of all surrounding machinery, and in every well- 
 ordered factory it is fixed over a large water tank. 
 The contents can be discharged at once through 
 an earthenware cock, underneath the leaden vessel, 
 should the electric thermometer ever ring too near 
 an approach, 104° Fahrenheit (40° Centigrade or 
 Celsus), the temperature at which spontaneous dis- 
 integration of the explosive occurs. Each apparatus 
 is provided with a safety-valve in the cover, also a 
 valve for the admission of glycerine under the 
 control of the operator, and a thermometer, as 
 already mentioned, with electrical connections, by 
 which he can watch the temperature and regulate 
 the flow of glycerine, he being protected behind an 
 earthen embankment. 
 
 The impure nitro-glycerine is first separated from 
 the residue of acids by decantation, or by a syphon,, 
 and conveyed through pipes by water-carriage to 
 another building, where it is thoroughly washed until 
 no acid effect is shown on blue litmus paper ; any 
 unperceived residue of acid being finally neutralized 
 in a bath of carbonate of soda in which it is agitated 
 by compressed air. 
 
 All acid fumes are carried away by a hood and 
 ventilating shaft of earthenware, into which a steam 
 
8o MODERN GUNS AND SMOKELESS POWDER. 
 
 jet is applied for the double purpose of providing 
 a certain amount of friction, and for dissolving a 
 portion of the acids. 
 
 Special Machinery for Smoi<eless 
 Powders. 
 
 The machinery required for making any kind of 
 smokeless powder is practically the same, and the 
 processes of mixing and thoroughly incorporating 
 under " stones " like mortar mills, followed by sifting 
 and granulating, are common to all. 
 
 Some smokeless powders are made into sheets, 
 through rollers, and cut into small squares, while 
 others, of which " Cordite " forms the chief repre- 
 sentative, are squirted through holes under the 
 influence of hydraulic pressure while in the form 
 of a pasty mass. 
 
 This continuous cord is received on reels and dried 
 by steam, so as to evaporate the solvent. It then 
 hardens, and is cut up into suitable lengths for use, 
 and the diameter of the "Cordite" determines its 
 rate of combustion and explosiveness. 
 
 Instead of filling cartridges with a powder as 
 usual, a number of cordite-rods are collected together 
 in a special machine, whereby they are pushed into 
 a cartridge-case, and cut off to the proper length. 
 The bullet is afterwards fixed in the usual manner. 
 
 Thus the difference between smokeless powder 
 
MODERN GUNS AND SMOKELESS POWDER. 8 1 
 
 and " Cordite " for rifles or for heavy artillery is not so 
 much in their composition as in their mechanical 
 condition, in size of grains for the one, or in the 
 thickness of rods for the other sort. 
 
 The object of these differences is to cause the 
 powder to burn more slowly, giving more time for 
 the shot to travel, thus reducing the strain upon 
 the gun. 
 
 The same factory, therefore, that would serve for 
 making "Cordite" or any other class of smokeless 
 powder, would provide the right material for rifles, 
 magazine rifles, or heavy guns. 
 
82 MODERN GUNS AND SMOKELESS POWDER. 
 
 Conclusion. 
 
 From the foregoing pages it will be seen that not 
 only the production of new classes of powder for 
 propelling shot and for bursting shells are in some- 
 what of an experimental stage at the present date 
 (1892), but that the influence of the changes now 
 going on profoundly modify the conditions deter- 
 mining design and construction of heavy guns and 
 rifled small-arms. 
 
 The great problem to the solution of which all 
 military authorities are chiefly directing their at- 
 tention at the present time, is to produce a powder 
 for guns which shall serve a double purpose : 
 namely, that of forming a suitable explosive for the 
 existing stock of guns and ri|les, and which shall at 
 the same time give higher results in rifled artillery 
 specially designed to suit its peculiarities. 
 
 All artillerists are working towards this end, and 
 some affect great mystery as to what they are doing ; 
 although their "secrets" are not always worth the 
 trouble of finding out. 
 
 A good deal of unproved theory has been put 
 forward from time to time in connection with guns 
 and explosives ; and it would be unwise to conclude 
 that any finality has been reached up to the present 
 time. But there seems no doubt that eventually a 
 complete reorganization of artillery must be made in 
 order to gain the fullest benefit of smokeless 
 powders, and there is some uncertainty as to the 
 
MODERN GUNS AND SMOKELESS POWDER. ^2, 
 
 complete lines on which such reorganization must 
 proceed. 
 
 There is, however, no doubt that some, if not the 
 major portions, of the benefits derivable from smoke- 
 less powders can be had by very little changes in 
 guns as made at present. 
 
 The practical conclusion of the whole matter 
 seems to lead to a gradual modification of new 
 artillery in the direction inculcated in the preceding 
 portion of this memorandum : in the meantime, 
 making the powder so as to suit existing guns, 
 and slightly varying the details of its manufacture 
 from time to time, as new guns supersede the old 
 ones. 
 
 By this moderate progressive system the greatest 
 efficiency becomes possible with the fewest changes 
 in existing armaments, and it only becomes neces- 
 sary to add supplements from time to time, that all 
 existing text-books may be brought up to date. 
 
LONDON : 
 PRINTED BY WILLIAM CLOWES AND SONS, Limited, 
 
 STAM~ORD STREET AND CHARING CROSS.