. Elements of transportation, a discussion of steam railroad electric railway, and ocean and inland water transportation . Turbines in the Governor Cobb Looking Forwaku in the Engine Room. passing the length of the engine, and from one row ofdisks to the next, is maintained hy the cylindrical casingor stator that surrounds the revolving shaft. The innersurface of the stator is covered with a sei-ies of rows ofdisks, wliich iire so placed as to face tlie disks on the inte-rior revolving shaft. The Boiler and the Furnace.—The engine applies the THE STEAMSHIP 217 power, the boiler generates it; a
. Elements of transportation, a discussion of steam railroad electric railway, and ocean and inland water transportation . Turbines in the Governor Cobb Looking Forwaku in the Engine Room. passing the length of the engine, and from one row ofdisks to the next, is maintained hy the cylindrical casingor stator that surrounds the revolving shaft. The innersurface of the stator is covered with a sei-ies of rows ofdisks, wliich iire so placed as to face tlie disks on the inte-rior revolving shaft. The Boiler and the Furnace.—The engine applies the THE STEAMSHIP 217 power, the boiler generates it; and it is the boiler thatdetermines the efficiency of the engine. The first boilerswere flat-sided and box-shaped, and the pressure of thesteam within them was as low as 10 or 12 pounds persquare inch. It was not possible to raise the pressureabove 40 or 50 pounds to the square inch until after 1868,when cylindrical boilers with internal furnaces were firstconstructed; after this had been done, the improvement. The Marine Boiler. of the boiler w^as merely a matter of detail. The mostimportant step made since 1868 has been the adoption ofcorrugated cylindrical furnaces. The marine boiler nowalmost universally used is one with internal corrugatedfurnaces, and wdth return horizontal tubes. In these boil-ers the fire passes from the furnace through the tubes, andthus up the stack. This is the fire-tube boiler. Some use is made of water-tube boilers. In these boil-ers the water is in the tubes and the fire passes around 218 ELEMENTS OF TRANSPORTATION the tubes instead of through them. Such boilers havegreater heating efficiency, but the tubes must be constructedof copper which is more expensive than steel. These boil-ers also cost more to maintain. Their use for this reasonhas been confined mainly to naval vessels, where expenseis a secondary consideration. The experience of the navywith water-tube boilers has not been very satisfactory, andtheir future use is not probable. From Wo
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Keywords: ., bookcentury1900, bookdecade1920, booksubjecttranspo, bookyear1920
