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Notes a n d Comments. \VAST•
[J. F. I.,
OP NATURAL GAS.
The reckless waste of the natural gas supplies of Pennsylvania, Ohio and Indial~a is one of the greatest economic crimes committed in this country. Millions upon millions of feet of this ideal fuel were not utilized at all, and other millions of feet were burnt in huge flambeaux to advertise town s i t e s . -
Engineering and 3~rining Journal. VANADIUM STEEL. Metallurgic circles, especially abroad, have been interested recently in the singular properties of vanadium steel. It appears that when from 3 to 5 parts per i,ooo of this metal, which is as yet very little known, are added to steel, it communicates remarkable properties. Properly 8peaking, vanadium does not bestow on iron or steel any new property, but it doubles the coefficients of resistance to fracture under all circumstances (shock, crushing, elongation, etc.), and at the same time imparts such extreme hardness as to render it possible to reduce almost by half the thickness of the armor for vessels. It is difficult to comprehend that the presence of from Y3 to ~/2 per cent. of any element whatever in an iron alloy can have so intense and general an effect, t h o u g h this effect is perhaps explained by the extreme avidity which under certain circumstances vanadium has for oxygen. This avidity might account for the fact that the presence of even the slightest quantities of vanadium in a bath of steel in fusion would lead to the immediate and absolute reduction of every trace of iron oxide still existing in the mass; now to these traces of oxide, which are inevitable without vanadium, the rupture of the best prepared steels is attributed. Crystals, even microscopic, of oxides would act like the stroke of a diamond on the thickest glass. A peculiar property of vanadium steels is that they acquire their maximum of hardness, not by tempering, but by annealing at from 700 ° to 800° C, This has various consequences; for instance, a planing machine whose cutter is of vanadium steel is set at work with the greatest velocity and power. Soon the implement becomes heated, and even when it attains red heat, it still continues to take off shavings of iron or castings without exhibiting any exhaustion. It is almost unnecessary to remark that in such a case a cutter of ordinary steel would become completely softened and lose its cutting power. This property is of particular importance for projectiles. It is k n o w n that the shock which they experience on striking the target raises t h e m to an elevated temperature. If, by means of vanadium, this temperature does not diminish the hardness of their points, and consequently all their sharpness, is preserved, the penetrating force will remain intact. The applications of vanadium may be numerous. It is said that they may cause a revolution in armaments. Incidentally, they would allow the construction of helmets and breast-plates, light and efficacious. Vanadium has been valued as high as 13o,ooo francs per kilogram. It i$ now, we think, worth about 15o franes.--L'Echo des Mines el de la Metal.
lurgie.