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ROASTING COPPER ORE checked by means of carbonic acid gas
which was made on the surface by comTHE burning mountain shown in this bining sulphuric acid and crushed lime
photograph is the outdoor “roaster" stone, then the gas was conveyed to the at Jerome, Arizona, where one of the mouth of the shaft where its own weight world's largest copper mines is operated. caused it to sink and displace the air in The ores contain a great excess of sul- the mine, thus extinguishing the fire. phur and before they can be economically smelted it is necessary to burn out the greater part of the sulphur. This is called heap roasting, the ore being heaped with cord wood and allowed to burn from five to nine weeks. About 500 tons of ore form a heap, so that the enormous quantity shown in the photograph may be estimated. The ore for roasting is trammed through a tunnel 1,300 feet in length, which leads from the 500 foot level of the shaft, and when roasted and ready for the smelter it is sent back into the mine and hoisted to the mouth of the shaft, as the country is so rugged that' there is no other way of reaching the smelter."
Owing to the exceeding richness of sulphur, 15 to 32 per cent., there is great danger of mine fires from spontaneous combustion. One very serious fire was
THIS PHOTO WAS TAKEN BY THE RAYS OF AN INTERURBAN ELECTRIC CAR LIGHT. The arc lamp is about fifteen inches in diameter and nine inches in depth. It illuminates for five hundred yards,
CATS AS ACROBATS. Cats are exceedingly difficult to train, having an unusually developed aversion to doing things they don't like, yet here is a photograph of three of them doing ''stunts" on a horizontal bar. These pets are owned and trained by a California photographer who finds much amusement and some profit also in taking their pictures in strange poses,
THE GIANT OF EUROPE CHE giant floating steam crane which 1 is shown is the identical crane which was used a little time ago in the salving operations on the submarine U 3, which sank near Keil. The German nation boasts of some of the most remarkable floating cranes in the world, and the one shown here is probably the most powerful in Europe. The gigantic size of the hooks and pulleys—capable of receiving 200 tons—shown in one of the illustrations, may be realized by comparing them with the man at their side. The arm of the crane is pivoted on its base, and the counter-balance weights are controlled by machinery. A monster of such power may well be regarded as one of the modern wonders of the mechanical world.
Huge PULLEY MAKES
MAN A PIGMY, An odd comparison of tiny man and his
VANADIUM IN STEEL VANADIUM, first discovered in 1801,
is a mineral which in late years has been applied with remarkable results in the steel industry. The reason it was not used sooner in the manufacturing arts was because of its scarcity. Large and exceptionally rich deposits of vanadium ores were discovered in the Peruvian Andes several years ago. It is to this source that vanadium steels hold their present commercial status.
Scientists in the employ of the French government first settled the question, “Does vanadium improve the quality of steel?” They proved that the addition of a small percentage of vanadiumnever above three-quarters of one per cent-gives to steel a remarkable increase in strength without impairing its
ductility—a result that cannot be secured from any other element used in the composition of steel. Carbon, for example, increases the strength up to a certain point but causes brittleness, and even fails to strengthen when employed in large amounts, the result of further additions producing ordinary pig iron.
Pittsburg manufacturers who have used vanadium in their steel products report extraordinary results. It is claimed that a two years' test of vanadium against ordinary steel shows an actual saving of $761.59 on a single item-a flue cutter weighing three ounces. In one year, 1,049 carbon steel cutters were used to cut 145,444 flues. In the next year 60 vanadium steel cutters cut 152,578 Alues. The average number of tubes cut with the carbon steel tool was 139; the average for the vanadium steel, 2,244. The cost of the carbon steel cutter per hundred flues was $.54 compared with one and six-tenths cents per hundred, with the vanadium steel tool.