Page:Popular Science Monthly Volume 91.djvu/430

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The Hottest Heat

The highest temperature ever reached by man is 9400° Fahrenheit By Raymond Francis Yates

��UNTIL late years the greatest heat man possessed as an industrial agency was that of the ordinary fuel furnace in which temperatures approaching thirty-two hundred degrees Fahrenheit were possible. While these temper-

��Oxygen

��atures were indis- pensable and im- portant utilities of industry at the time, they are insignifi- cant today in com- parison with the heat employed in the commercial pro- duction of rubies, calcium carbide, car- borundum, graphite, and steel.

The two great allies of man today in the production of heat are, in order of their importance, chemistry and elec- tricity.

A gas composed of mixed hydrogen and oxy- gen when ignited burns so furiously that it pro- duces a temperature of thirty-six hundred de- grees Fahrenheit. Util- izing the combustion of these two gases as a source of heat, a French- man, M. Verneuil, has commercially pro- duced rubies, by fusing alumina with a trace of chromium oxide as the coloring medium. So perfect is this imitation gem that it is chemically impossible to dis- tinguish it from the natural article.

The oxy-hydrogen blow- pipe is abo used for welding. The temperature of the flame is just beyond the melting point of quartz, and by its use, tubes, flasks and many different pieces of quartz chemical apparatus are constructed. Quartz vessels are invaluable in

��chemistry. They resist most acids and rapid changes in temperature.

The Wonderful Thermit Process

The next step in realizing high tempera- tures by means of

���Workman welding a broken steel frame with heat from an oxy-acetylene blowpipe

��Hydrogen-

��F

��Granulated Carbon%

���Iron Cylinder

Professor Moissan made wonderful imitation dia- monds with this apparatus

��rapid chemical ac- tion was discovered by Professor H. Goldschmidt, of Es- sen, Germany. This is called the "ther- mit" process, and it produces a tempera- ture as high as thirty- four hundred degrees Fahrenheit. A furi- ous heat is produced by thermit because of the great chemical affinity existing be- tween oxygen and aluminum. If gran- ulated iron oxide and aluminum are mixed together and prop- erly ignited, the iron rapidly loses its oxygen to the aluminum accord- ing to the following simple equation:

Aluminum-firon oxic!c = Aluminum oxide+iron

After the reaction has been completed, the iron will be found in a molten state just beyond its boiling point. The oxides of many other elements act in the same manner. This makes the thermit process a* very valuable asset to the metallurgist and chemist. Not only has thermit proved itself an ally of the metallurgist, but of the engineer and mechanic as well. It has been found that if a small amount of titanium is placed in thermit, it forms an alloy with the molten iron which makes it invaluable for welding pur- poses. A few years ago, a fractured casting, no matter

��An oxy-hydro- gen blowpipe used for weld- ing purposes

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