ALUMINIUM.

Waipukurau Press, 2 June 1922, Page 4

ALUMINIUM.

A WOMDERFUL METAL. •, > ' I \ There is more aluminium in> the earth’s crust than aiiy other A metal, but 40 years ago it was practically unknown (writes H. Williamson in “Everyday Science’’). It was looked upon as li chemical curiosity, and was worth more than its weight in gold. It is realted that the Emperor Francis Joseph, when n child, had an aluminium. rattle that cost £2OOO. To-day the eonsmption of aluminium runs into many thousands of tons annually, and the cost is a little more than a shilling a pound.. It is a metal of extraordinary varied uses, many of which are quite unsuspected by the general public. Rolled into sheets, everybody knows it in the form of aluminium cooking vessels or motor car bonnets. But it can also bcrolled into sheets almost as thin as tissue paper; and much of the “tinfoil’’ or “silver paper’’ used for wrapping sweets and cigarettes is nowadays aluminium foil. Pounded into flukes or granules, it reveals entirely different properties. The tiny, thin flakes are the basis of aluminium paint, but they are also highly inflammable, and violently explosive if suspended in air. The flakes are used in fireworks, and cause beautiful star-shaped, bluish-white sparks. The granules are no loss combustible. They form the principal in gradient in the powerful cxplosixvo ammonal, and they combine with black oxide of iron to make the mixture known (is “Thermit,’’ whieh the Zeppelin bombs were filled with. When heat is applied to the niixlune, the aluminium combines fiercely with the oxygon of the iron, and produces a heat so great that heavy steel tramway rails are qnickl.v raised to a temperature nt which they mav be welded together.