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TURBINE

1953

TURENNW

§ard to them, some including the Dravidian ialects of southern India and others considering the Mongol and Manchu dialects to be distinct languages. The Finnic branch of languages is superior to the others, having some national literature, as the legendary and popular songs of the Finns and Hungarians. Consult Muller's Science of Languages or Peile's Philology. See AUSTRIA-HUNGARY, FINLAND and LITERATURE.

Tur'bine, a form of steam-engine in which the rotation is produced by the impact of a jet of escaping steam on the blades of a wheel. There are two forms of the turbine in use: the Parsons and the De Laval. In the Parsons turbine the steam from the boiler strikes the blades of a series of turbines fixed on one shaft, and finally escapes into a condenser or into the atmosphere at a low pressure. In the De Laval turbine the jet of high-pressure steam strikes a series of steel-buckets on a wheel similar to a Pel-ton water-wheel. The speed of turbines is very high. That of a 150 H. P. Parsons turbine is ^4,800 revolutions per minute, while that of a 50 H. P. De Laval machine has the enormous speed of 15,000 revolutions per minute. These very high speeds require special reducing-gearing before use for most machinery. The Parsons turbine was first successfully used directly on dynamos and also on the shafts of the propeller of an experimental steamer, the Turbina. This was then the fastest boat in the world, having made 34^- knots per hour. It is 100 feet long, and has three turbines of a total H. P. of 2,000. Tests of turbines have shown a remarkably low consumption of steam per H. P., that of small turbines rivaling that of the best, large, compound steam-engines. For steamships a great advantage claimed, in addition to economy, is that of the small size and weight of the turbines. Mechanically the turbine has the great advantage over the piston steam-engine in that no mechanism is needed to change a backward and forward straight-line motion into rotary motion. Much is being done to develop the turbine, but practically there are only two ways of increasing its efficiency. One is to improve the machine; the other is to improve the management of the working fluid. In general, the larger the marine turbine, the simpler the construction, the higher the steam's efficiency and the lower the rate of rotation. In 1899 turbines 35 and 50 inches in diameter were used in The Viper t a torpedo-boat destroyer; and though this is only 210 feet long and of 375 tons displacement, the turbines developed 11,000 horse-power and over 43 miles an hour. No vibration was produced, the engine-room being so quiet that it was difficult to realize the presence of the engines. In 1901 the turbine was applied to passenger steamships and the steamer (of 1,429

tons) averaged i8J knots an hour. The success was so pronounced that the Cunard Company at once built The Lusitania and The Mauretania (see STEAMSHIPS) and equipped each with quadruple-screw turbines. The commercial practicability of the turbine has been demonstrated.

Tur'bot, one of the flatfishes found in almost all European seas. It ranges from the Mediterranean to the coast of Scandinavia. It is highly esteemed as food, being the best of all the flatfishes in that regard. It is a large fish, sometimes reaching a weight of 70 pounds, but that weight is very exceptional. It feeds on crabs, small fishes, sea-urchins and fish-eggs. The true turbot does not occur on the American coast. An entirely different flatfish, of smaller size, is incorrectly called turbot in the United States. See FLATFISH.

Turenne (tti'r$n')9 Henri de la Tour D'Auvergne, Viscount de, a great French soldier, was born at Sedan on Sept. n, 1611. He was sent to Holland to study the art of war under an uncle of his, the celebrated Maurice of Nassau. He joined the French army, serving in Germany, where he relieved Main-z, besieged by the emperor's army. He then was attached to the Swedish army under Bernhard of Saxe-Weimar, where he captured several towns, and later defeated the Austrians and Spaniards at Casale and took Turin. After his conquest of Roussillon in 1642, he was made a marshal of France and given chief command on the Rhine, when he defeated the Bavarians at Rottwell, but was himself defeated at Marienthal. With Conde he avenged this defeat at Nordlingen. Turenne finished the war by conquering the electorate of Treves and (with the help of the Swedes) Bavaria, and conducted a successful campaign in Flanders. In the civil wars in France Cond6 and Turenne, the two greatest generals of the period, were on opposite sides, and Turenne with inferior forces was uniformly victorious, finally driving Conde from France. He then conquered much of the Spanish Netherlands. Louis XIV made him marshal-general of France, and only his Protestantism prevented his being appointed constable. Bossuet's celebrated Exposition of Christian Doctrine was written at the king's suggestion to effect the conversion of Turenne to Roman Catholicism, and aided by the king's solicitations was successful. In the campaign in Holland in 1672 he compelled the Elector of Brandenburg to beg for peace. His last campaign is disfigured oy the devastation of the Palatinate, where he burned 30 towns. His desire to retire could not be gratified, as he was the only general that could successfully oppose Montecuculi, the great Austrian general, and for nearly half a year their strategy was the admiration of Europe. Having forced his antagonist to