August 5, 1920] 



NATURE 



711 



These features have been little altered by later 

 experience. Chemists were trained on this small 

 plant for the purpose of starting- Government 



ed to demon^tiate the T.N.T. process, 



and private factories, and for a time a few tons 

 a week of the product were purified by alcohol- 

 benzene in another plant erected in the Depart- 

 ment to supply the Service with high-grade 

 T.N.T. for exploders. 



A study of T.N.T. in all its aspects was under- 

 taken. Much attention was given to the chem- 

 istry of T.N.T., the proportions in which the 

 isomers occur in the Crude product being deter- 

 mined by thermal analysis, and investigations 

 made on their interactions, stability, sensitive- 

 ness, heat values, and explosive properties. 



Amatol. — As it soon became evident that the 

 supply of the high explosives in use, lyddite and 

 T.N.T., would not suffice, the Department put 

 forward mixtures of ammonium nitrate and 

 T.N.T., the amatols, as a result of study of their 

 properties and of the violence they exhibited in 

 shell-burstingf trials. Gun trials substantiated the 

 trials at rest, and their adoption quickly followed. 

 Various methods of filling these mixtures into 

 shell were at this time worked out, many of which 

 have since been applied on the very largest scale. 



It was found that 80/20 amatol (80 parts of 

 ammonium nitrate to 20 of T.N.T.) was less easy 

 to bring to detonation than lyddite or T.N.T., and 

 required special arrangements in the train of 

 initiation of detonation. These were successfully 

 devised, and good and trustworthy detonation of 

 our shell was secured. An illustration is here 

 given (Fig. 3) of the fragmentation of an i8-pr. 

 shell filled with 80/20 amatol. 



As 80/20 amatol is practically smokeless, the 

 constituents being- arranged for complete com- 

 bustion, mixtures producing a white smoke for 

 indicating the point of burst were worked out for 

 inclusion in the shell-filling. Ultimately, amatol 

 NO. 2649, VOL. 105] 



became practically the only explosive for land and 

 aerial warfare, and justified its choice based on 

 the early estimate of its properties and capa- 

 bilities. In J917 the production 

 was at the rate of about 4000 

 tons a week. It is economical in 

 that it makes use of a cheap in- 

 gredient, and has explosive pro- 

 perties that render it very suit- 

 able for the purposes for which 

 it is used. 



The Department continued the 

 study of amatol especially with 

 regard to its chemical stability 

 and compatibility with the various 

 materials with which it came into 

 contact. Certain impurities in 

 ammonium nitrate were dis- 

 covered to be objectionable, and 

 investigation of this led to an im- 

 provement in the purity of the 

 ammonium nitrate supplied. 



R.D.B. Cordite.— When the 

 available quantity of acetone be- 

 came quite inadequate for the 

 cordite required, the Department 

 brought forward a new type of 

 cordite (Research Department 

 " B " or R.D.B. cordite) as a result of experimental 

 incorporations with ingredients chosen to give the 

 same ballistics as ordinary cordite. It could be 





jf3 



Fig. 3.— Fragmentation of i8-pr. shell by 80/20 amatol. 



made with no alteration in the plant required 

 for the manufacture of propellants. Instead of 

 acetone, the solvent employed was ether-alcohol. 



