414 



NATURE 



[July 24, 1919 



SCIENCE IN INDUSTRY. 



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iKic I'hoducis 



IN the course of his k^cture on "" Explosives " at 

 the British Scientific Products Exhibition on 

 July 18, Mr. James Young, Royal Military Academy, 

 said that during the war ammonal was found to be 

 very suitable for use in military mines and in trench- 

 warfare weapons, being safe and powerful, and having 

 a moderate velocity of detonation. It is equally suit- 

 able for industrial use, and the expensive constituent 

 ■ — aluminium — can be reduced to 3 per cent. Blastine 

 was also much used for the same purposes, and as the 

 main constituent, ammonium perchlorate, is now 

 made by electrolytic processes, it has a promising 

 future in industry. It is much more sensitive than 

 ammonal, and therefore not so safe to the users. The 

 invention of amatol, a mixture of T.N.T. and am- 

 monium nitrate, was of great value, and doubled our 

 resources of shell high explosives. As compared with 

 picric acid (lyddite), it is safer to handle, costs about 

 one-third, but is not so shattering, owing to the lower 

 velocity of detonation. It is also suitable for indus- 

 trial use,* and mixtures with as little as 10 per cent, 

 of T.N.T. are effective. 



Referring to the important subject of a national 

 factory for the fixation of nitrogen, Mr. Young 

 pointed out that our industries ■ are dependent on 

 national security, which again . depends on an 

 Army and Navy provided with an adequate supply 

 of explosives, so that if some industries are key indus- 

 tries, explosives are a master-key. The materials for 

 these should, so far as possible, be home products. 

 Now, nitrates are the foundation of nearly all our 

 military explosives, and most of the others in use, and 

 practically all our nitrates, come from far overseas. 

 If we had been cut off from, our supplies during the 

 war it is doubtful if our chemists could have filled 

 the gap in time, for the new artificial processes for 

 the fixation of nitrogen require much experience for 

 their efficient working. A great national factory for 

 the fixation of nitrogen should be established in Eng- 

 land without delay. \\'(> are already behindhand. 

 The Germans, with more experience, were able to 

 make their own nitric acid for carrying on the war. 

 America has already established a national factory. 

 Millions are to be spent on airships, with problematic 

 results, but, with experience, good returns from such 

 a factory should be a certainty. It would have unique 

 advantages. The principal raw materials are air and 

 water. Nitrates and ammonium compounds are in 

 great demand as fertilisers. In peace the main pro- 

 duction would be used as fertilisers and for industrial 

 explosives, and be ready to be switched on to war, if 

 war should come. It would at the same time increase 

 the security of the nation and its agricultural 

 prosperity. 



Mr. L. Bairstow pointed out, in his lecture 

 on July 21, that the record of some of the striking 

 developments in aviation in the war period has been 

 presented in such a way as to form an indicator of 

 further progress. In forming the .\dvisory Committee 

 for Aeronautics in 1909 the British Government 

 showed a wise foresight, for in the hands of a body 

 of men of science inquiries have been systematised and 

 coherence given to a literature which has had a pro- 

 found, influence on British aviation. Attention was 

 directed to specific cases of valuable experimental work 

 both on the model and full-scale. In many ways the 

 use of models under carefully controlled laboratory 

 conditions forms the best means of attack on a new 

 problem. There are scale effects which reduce the 

 accuracy of direct application to the full scale, but 



NO. 2595, VOL. 103] 



many of them are known, particularh iIkim tor the 

 main parts. A diagram was given which illustrates 

 the cxtrenicly close relation between tests on large and 

 small wings; the experiment is one possessing a 

 considerable degree of accuracy, and the distribution 

 of pressure is sensitive to changes of angle of 

 incidence. The agreement is probably complete within 

 the accuracy of the full-scale exp<Timents, and a com- 

 mittee formed to discuss the value of model experiments 

 concluded by saying : — " It is of great importance that 

 such information should be increased and its us<' 

 extended by further systematic full-scale research." 

 In dealing with stability, records were shown of the 

 disturbed motions of aeroplanes. Easily obtained, 

 these records show whether an aeroplane is stable or 

 unstable and the degree of its stability. .Several types 

 of disturbance were shown, including those of an 

 aeroplane which tends to turn upside down, one which 

 "hunts," i.e. shows an increasing oscillation, and 

 others which are stable. The motions indicate d b\ the 

 records are calculable on the mathematical basis given 

 by Prof. Bryan if use be made of the resistance deriva- 

 tives found in the aerodynamical laboratories. It is 

 in the collection of the latter from specially conducted 

 experiments that the immediate future holds its most 

 important research work. 



k conference on "Patents in Relation to Industry'' 

 will be held at the exhibitipn on Thursday, July ^-,1, 

 at 4.30 p.m. Lord Moulton will preside, and among 

 those who will take part in the discussion are Sir 

 Robert Hadfield, Mr. ^V. S. Reid (chairman of 

 council of the Institute of Inventors), Mr. W. R. 

 Bousfield, Mr. Douglas Leechman, Mr. ^\'. M. 

 Mordev, Mr. James .Swinburne, and Sir G. Croydon 

 Marks. 



COTTON AND COTTON-SEED 

 INDUSTRIES. 



IN an address delivered by invitation before the 

 Manchester Textile Institute on May 28, Mr. 

 E. C. de Segundo discussed the interdependence of 

 the cotton and the cotton-seed industries. Until about 

 i860, cotton-seed from the%)lants yielding the cotton 

 imported to Lancashire was a waste product. The value, 

 to the United States alone, of this once waste pro- 

 duct was, just before the war, with an average cotton- 

 seed crop, from twenty to thirty millions sterling. 

 Some 95 per cent, of the seed now utilised retains, 

 however, residual fibre to the extent of from 2 per 

 cent, in lightly fibred Indian seed to 12 per cent, of 

 the seed-weight in American Upland, Uganda, and 

 other woolly varieties. This residual fibre includes, 

 besides the " fuzz " proper, some "staple" which has 

 escaped the gin and other fibres too short to be in- 

 cluded in "staple." Some part of the residual fibre 

 which is not "fuzz" has long been recovered by saw- 

 linting machines, as "linters," mainly marketed in 

 Germany. 



The successful removal of the proper "fuzz" with- 

 out injury to the seed or to the short fibres has been 

 a more 'difficult problem. The potential value of 

 "fuzi" has long been recognised, but the attempts to 

 separate the "fuzz" at first gave a product marked 

 by the defect of admixture with pieces of seed-shell 

 and foreign matter. Since 1909 a machine has been 

 in use which turns out " fuzz " in a clean, marketable 

 form free from this defect. Before the war 2000 tons 

 of these short fibres had been imported to Britain for 

 paper-making. During the war 8000 tons of this 

 " hull-fibre " have been used by one L^nited States 

 firm in making explosives. 



.\merican practice removes the residual fibre in 



