5D< 



NATURE 



[October 26, 191 1 



which may be summed up in the one 

 word " suitable." Every nation adopted a powder 

 in which nitrocellulose played the leading pari, 

 the variants being the proportions of nitroglycerine 

 and the quantities and qualities of additional 

 restrainers. 



For a time all went well; but we, as a nation, were 

 pointed at as being behind the times because our 

 cordite, since it contained rather a large proportion of 

 nitroglycerine, developed more heat, and produced 

 more bore-erosion than powders of what had become 

 practically pure nitrocellulose. But soon a cloud, no 

 bigger than a man's hand, appeared above the horizon, 

 and it was found that this class of propellant exhibited 

 an almost sentient dislike to extremes of temperature. 

 Not being a mechanical mixture, like the old black 

 powder, it proclaimed itself a chemical compound with 

 a marked tendency to instability, in a somewhat dis- 

 concerting manner. Great heat disorganised it alto- 

 gether ; extreme cold brought the nitroglycerine, if 

 there were any used in the manufacture, to the sur- 

 face, and this did not add to the gunner's confidence 

 in it. The tendency to deterioration from exposure to 

 undue heat, however, was seen to be the more to be 

 feared of the two, and it was a drawback with which 

 it was exceedingly difficult to deal. So far as cordite 

 was concerned, it was found to remain stable at tem- 

 peratures under 8o° Fahr., but in some of the older 

 ships, owing to steam pipes being- led near, and even 

 in some cases through, the magazines, temperatures 

 as high as 140 were recorded, and these were 

 equalled by those in limber boxes in some stations 

 in India. 



To keep a check on this deterioration the heat test, 

 invented by the late Sir Frederick Abel, has always 

 been used in this country and in the Colonies, and 

 to its frequent application is most certainly due our 

 immunity from explosions on board battleships. One 

 is almost tempted to write unberufen before stating 

 that we are exceptional among the larger navies in 

 having not lost a ship by the explosion of its 

 own powder. We have had our warning and have 

 profited by it. Some ten years ago a cordite cartridge 

 ignited on board one of our battleships, but did 

 not fire those around it. Up to 1906, when spon- 

 taneous ignition of cordite took place with what might 

 have been disastrous results at Haiderabad and 

 Ferozepore, cordite, with the exception of the one 

 cartridge mentioned above, had not given rise to an 

 accident in thirteen years. Catastrophes were averted 

 at ^ both these places by conspicuous acts of 

 daring on the part of officers and men, in 

 the first-named by drenching boxes of cordite 

 set smouldering by one in which the cartridges had 

 fired, and in the other by the removal of nine tons 

 of black powder from a burning magazine within 

 a few feet of which were stored 135 tons of black 

 powder. 



There is now little doubt that the destruction of 



the United Stntes ship, the Maine, was due to the 



spontaneous explosion of her own defective powder, 



and also of other ships which have since been similarly 



lost ; the Japanese have lost two, the French two 



(including the Liberty), and the Brazilians one ship. 



About four years ago we began to set our house in 



rder by installing cooling apparatus in the vicinit) 



of the magazines, by which the temperature is kepi 



below So Fahr., and Hie ventilation system gives the 



res what may lie described as an atmospheric 



ing, as the surrounding air is being constantly 



I and changed. Great care is taken, moreover, 



in the construction of our ships to protect the maga- 



From heat given off from boilers and steam 



NO. 2 TQ I, VOL. 87] 



pipes. It is natural that both magazines and boilers 

 should be placed below the water-line, and in thi 

 least vulnerable part of the ship, and that, therefore, 

 they should find themselves fairly close together ; but 

 a good thickness of insulating material can be inter- 

 posed, and the lagging of steam pipes, purposely 

 added to ensure the retention of heat, much diminishes 

 radiation in their vicinity. Such precautions as these 

 serve to reduce risk of spontaneous ignition to a 

 minimum, and they are well worth the initial cost; 

 but alone they are insufficient, and to them must In 

 added periodical examinations of the propellant, the 

 heat test being then the detective. 



It would appear that gelatinised nitrocellulose is 

 liable to be attacked by an organism which rapidly 

 brings about its deterioration, and that nitroglycerine 

 acts to a certain extent as an antiseptic. Another 

 theorv is that the nitroglycerine hardens the sub- 

 stance, and renders it less susceptible to climatic in- 

 fluences. The net result, however, is that pure nitro- 

 cellulose is undoubtedly less stable than nitroglycerine 

 compounds such as cordite, and that the measure of 

 immunity of the latter from effects of extremes of 

 temperature' varies directly with the proportion of 

 nitroglycerine. The main difficulty, therefore, witli 

 which the authorities have to contend is the natural 

 ing towards a propellant which will be proof 

 against baneful climatic influences, even though it may 

 have a greater erosive effect on the gun. For naval 

 services these considerations have to be nicely balanced, 

 but the preponderance must ever be on the side of 

 Guns can be changed when worn out, and 

 their cost, when compared with that of a ship and 

 its crew, is negligible; hence the absolute necessitj 

 for cooling apparatus, the insulation of the magazines, 

 effective drowning arrangements, and periodical in- 

 spections of the powder. 



Nitrocompounds have one great advantage over 

 Mack powder — they do not explode with nearlv the 

 same violence unless very closely confined. Even 

 when, as in the case of the Ferozepore conflagration, 

 the cordite is confined in metal-lined cases, it only 

 burns with great vehemence, and, with effective flood- 

 ing arrangements, there should be time to prevent 

 disastrous explosions on board ship. At Ferozepore 

 the removal of the black powder, as described above, 

 averted what might have been a terrible disaster. 

 On board battleships the gases evolved by a large 

 conflagration of any nitro-compound would be con- 

 fined, more or less, by the protective steel deck, bulk- 

 heads, and watertight doors, but ' it is difficult to 

 account for the terrible disruptive effects manifested 

 in the explosion in the ill-fated Libertd. It is prob- 

 able, however, that she had on board her full com- 

 plement of high explosive (Melinite) shells. The 

 intense heat of burning cartridges would probablv fire 

 one of these, and this would certainly detonate those 

 in the same shell-room. This, of course, is only 

 conjecture, but the curious tearing of steel plates, and 

 the projection of large pieces of heavv armour to 

 great distances, would seem to point to something 

 more in the nature of the detonation of a high explo- 

 sive than the upheaval that would be caused by the 

 imprisoned Leases of a propellant. The inquiry into 

 t!ie cause of the catastrophe will no doubt throw light 

 on tlii~ point, but its fatal consequences will tend to 

 make all nations redouble their precautions, not only 

 as regards the storage in battleships, but also in »^- 

 dircction of extreme care in the selection of a pro- 

 pellant which shall not onlv meet ordinary Servics 

 requirements, hut on the stability of which they may 

 place absolute trust. 



DrsMON'P O'Cu.I AGIIAN. 



