SINEWS OF WAR

New Zealand Listener, Volume 3, Issue 70, 25 October 1940, Page 3

SINEWS OF WAR

The Use Of Metals And Minerals

Ts: five big "M’s" of modern warfare are Men, Money, Munitions, Minerals, Metals. Little is known of the Minerals and Metals, perhaps because they do not lend themselves to spectacular stories, but without them the war would soon be over. Here are some facts about these strange products which contribute to the defence of the nation: "A cargo of 10,000 tons of bauxite has been detained by the contraband control." You have read statements like that on many occasions, and may have wondered what it is about bauxite that makes it so important. Bauxite is the mineral from which nearly all the world’s aluminium is produced, and aluminium is one of those metals that have become as essential to mechanised warfare as iron or steel. Although aluminium is the commonest metal, being present in almost every clay and rock, very few minerals contain it in a sufficiently high percentage to make it economic to extract the metal.

France is the chief source of bauxite, with Hungary, U.S.A., Dutch Guiana, Italy and Yugoslavia following in that order. It takes about 4 tons of bauxite to produce one ton of aluminium, plus a considerable quantity of electricitythe equivalent of four tons of coal for every ton of aluminium. We are apt to think of aluminium in terms of aeroplanes, but it has hundreds of other uses. Many people imagine that aluminium is the lightest metal in general use. This is not correct-mag-nesium is lighter, a metal of which Germany has considerable deposits and is the highest producer. Magnesium is roughly two-thirds the weight of aluminium, but it is not so strong. It can be alloyed with other metals to increase its strength, but German aeronautical engineers have been inclined to build on the theory that a warplane is not likely to last long, so that "built to last" is waste of materials. What is Cinnabar? If you read of cinnabar being detained, you may remember that this is the mineral from which mercury is obtained and wonder why a metal with which you are chiefly familiar in thermometers and barometers should be considered contraband. It would be difficult to fight a modern war without mercury. The discovery of mercury fulminate, which detonates when struck, revolutionised warfare. It made possible the cartridge, the quick-firing gun, breech-loading, with shells and torpedoes which exploded on contact. There are substitutes for mercury in detonators, but they are not easy to manufacture. In modern war, measuring instruments play a very important part. The properties or density of mercury render it ideal for barometers, its conductivity of heat ideal for thermometers and its electrical properties ideal for contactbreakers. A country cut off from its mercury supply would be seriously handicapped; it would have great difficulty in securing effective substitutes. A great deal is heard about Germany’s iron supplies. War cannot be fought with iron alone. Indeed, pure iron would not be of much use-it is an expensive chemical curiosity. Minute quantities of other elements are necessaty to produce the hard, yet tough, metal which forms armour plate, or the wear-resisting steel of gun barrels. A little of these other elements goes a long way in making the steels necessary for modern war-but this little is as essential as the vitamins in our daily diet. : Everybody Has It One of these elements every nation has in plenty-carbon. The others come from all parts of the world. One of the most important is nickel, of which about 90 per cent. of the world’s production comes from Canada. Europe produces only about 3 per cent. of the world’s nickel needs. Another is manganese, produced by Russia, India, South Africa and other countries. Manganese serves a double

purpose in steel. It gets rid of impurities, ensures sound metal and it forms alloys with valuable properties. It is possible to use other substances, but it is doubtful whether they are as effective. Germany paid a million pounds for manganese in 1938. Chromium and tungsten are two other metals the steel-maker needs. As with the other metals, only small percentages -from 0.5 to 5-are required, but these percentages are essential to the best work. Steel can be made without them -as they made it before the new steels were discovered-but the handicap would be tremendous. Some of these metals, such as tungsten, are necessary for making the tools that make the weapons. This metal is also used for electric light filaments. Electric lamps, incidentally, call for nickel. A high nickel alloy has the useful property of having exactly the same rate of expansion when heated as glass -hence its use in lead-in wires in all kinds of electric lamps, and _ wireless valves. The only other suitable metal is platinum. Platinum is necessary for the chemical industry, but our contraband control is not likely to catch much of it except, perhaps, in jewellery. It has the advantage that it seldom "wears out." Goes Up in Smoke Tin must now be considered a strategic material, for apart from canning 1! is used in certain parts of machinery, Asbestos is unique in its fire-resisting properties, and should be a material easy to control, since it comes from overseas,

Mica for insulators might be considered a strategic material, but substitutes would not be hard to make. There are many other materials which might be listed as strategic. Molybdenum, for instance, is an excellent substitute for tungsten of which by far the greater part of the world’s production is in the U.S.A., with only Norway in Europe producing two or three per cent. of world eensumption. Titanium has the property of forming a compound that divides easily into minute fragments — ideal for smokescreens, the white particles forming em impenetrable cloud.