USKK 14. t9l8 



NATURE 



217 



on is nun. 1 n powder 



llei mass to 

 the initial shock; but the wave travels slowly, 

 ma\ die out in a I 

 1 1 1 i ~1 fact in detonating shells. Detonation 



pellets, and transmitted to the 

 filling. 



Mixtures of high • hich require 1 



Amatol a mixture of T.N.T. and 

 nitrate, is more difficult re 1 .N.T. 



Ammonium X Urate Mix 



Ammona ■■ besl know n and mosl us< d 

 of the ammonium nitrate mixtures is ammonal, in 

 which use is made of the great heat given out bj the 

 inn of aluminium. A mixture of aluminium 

 powder with the theoretical amount of ammonium 

 nitrai ddation would contain 8i-6 per 

 ol Nil NO,. It would yield 157s calories per 

 much as nitroglycerine— and 682 c.c. 

 IU11 such a mixture is difficult to detonate, 

 : was added '<> make it nun.' inflammable. 

 All cartridges musl be hermeticall) sealed to pre- 

 rrioisture, which quickly ruins am- 

 monal. 'I lie velocitj of detonation is about j mi tres 



effect intei mediate between thai 

 ind 1I1. 1 1 "i >l' namiti . It- pow er is 

 m four times that of gunpowder. 

 .;,:,. I his is mbling am- 



monal, but calcium silicide, Ca Si, an elect 

 product, takes thi place ol h aluminium. Its com- 

 - is «lo 



Ammonium nitrate ... ... 78 



Trinitrotoluene ... ... ... 8 



Calcium silicide ... ... ... 14 



It is detonated in thi sat 

 has about tin same power. 



Mm - ■ un ■ lium nitrate 



and T.N.T. in va which is now "I 



importance. T.N.T. does ni 

 jen for its complete combustion, and although 

 the addition of ammonium nitrate increases the 

 weight of the charge, the inn— ol thi heat 

 out more than compensates for this. 



The higher the proportion of ammonium nitrate, 

 ■ the difficulty of detonaticn, and the diffi- 

 culty increases when the ammonal is melted and 

 into solid blocks or slahs, as is necessan fot 

 shells. Hence the highi used in the 



v.der for bombs, grenades, and mines 

 detonated by fulminate d others, used 



for shell-filling, are detot ods, and 



will he referred In later. 



All varieties of amatol are powerful high explosives. 

 Thi di tonation is about 4.500 meti 



II are spoiled bj mi listure and mi 

 waterproofed, and all are practically smokeless. 



Chlorate Mining Explosives, 



All thi older chloi much too 



in lar^' quantitii - in military 1 



1897, that if 



tin- chlorate mixture contained ■ iils or fats its sensi- 



itly d 1 ntirely 



r,f blasting explo 



Blastine. — This i- militan 



, |uantitii s havi been used 



!•■ pies. -lit « II I 



nical military bias following 



n : — 



2559, VOL. I02"] 



Ammonium perchlorate ... ... 60 



Sodium nitrate ... ... ... 22 



Trinitrotoluem ... ... ... 1 1 



Paraffin wax - 



It i- made in the form ; .uiil.it 



,1 ssed. 



/'. 1 mite. This is a mixtui 1 between 



ammonal am I on as am- 



1 in which thi placed 



nsequent diminution in power 

 ensated for bj using ammonium p rchlorati 

 id of the nitrate. It is made in several varieties. 

 All the chlorate explosives require fulminate detona- 

 tors, and for this reason, besides being too sensitive, 

 an- unsuitable for use as a high-explosive shell-filling. 

 'The 1.1 1 ition is 4.000 to 5000 metres per 



sei ond. 



Mixtures of ammonium perchlorate and paraffin 

 wax with combustibles such as aluminium powder or 

 Umeal are also used, an. I an powerful high 

 . xplosives. 



I hermit, now an important munition of war, is in 



•1 class by itself. It is used f ; ini epdiary 



. and sometimes in a kind "I" shrapnel. A small 



explosive charge scatters the contents, which rain 



bits of blazing iron, which will instantly set fire 



to an) thing capable ol burning. 



Nitrocellulose, containii cent of nitrogen 



in alcohol-ether, or at 'e.^t completely 

 gelatinised by it, is now made on an enormous scale, 

 and constitutes 99-5 per rem. of nitrocellulose smoke- 

 less powders, as well as being us..', in the new cordite. 

 Guncotton was formerly used exclusively for tor- 

 pi do warheads, marine mines, etc., but has now been 

 iced by T.N.T. and ammonium nitrate and 

 mixtures. 

 There are two varieties of smokeless military 

 powders in us nt : (1) Nitrocellulos< 



which consist of nt. of gelatinised nitro- 



cellulose, and 0-5 per cent, of a preservative; and 

 is. which are gelatinised mix- 

 tures ol nitroglycerine and nitrocellulose, with a few 

 p.r cent, of a stabiliser. 



American nitrocellulose powder (N.C.T.) is typical 

 of the first class. It is made from soluble nitro- 

 cellulose containing about 125 per cent, of nitrogen. 



N.C.T. is a good powder, and fairly stable. It is 

 the weakest of the smokeless powder-. Charges must 



bout 10 per cent, heavier than with corditi 

 give the same muz.de velocity. 



N.C.T. is now much used" in our Service for guns 



and howitzers, the charges In ; "■'' the 



mizzle velocity as corditi' M.D. 



Cordite Mk. I. is a ven powerful propellant, but 



owing to the high temperatures produced it is very 



erosive, and as a result of the Smith African War 



lifi, ,! corditi , "Cordite M.D.," was introdu 

 It has the composition: guncotton 65, nitroglycerine 

 ;,,, mineral jellv 5. Its powei is about 10 per cent. 

 Mk. I., hut the e U ns last three times 

 as | on g. Cordite M.D. is the standard British pro- 

 pi II., ni'.' although others are usi d at present. 



In a new modified cordite soluble . nitrocellulose is 



used instead of guncotton, and alcohol-ether is used 



itinisation instead of acetone. It contains 



a larger percentagi ol nitroglycerine than cordite M.D., 



but Ps ven similar, although not quite so powerful. 



High Explosives foi Shell-filling. 

 \ high "i order to be suital 



filling, must possess special qualiti 

 wlun ii is 'used for other pu p in bombs 



■ does. 



