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Show JHE MODERN STEAMSHIP. " fmpocslble to Guess What Speed May Naft Be Keat.lied Hereafter. Twenty years ago it was thought by many tht the- limit as to size, speed and economy had been reached. At pres-ent pres-ent it seems that the draft of water at the harbors and the cost are the limits that will prevent further development on present line. With different material ma-terial for construction, with liquid fuel, and other improvements or inventions, it is possible that 20 years from now one may look back at the Lucania with her 21. U knots as we look back on tha Germayiu and Britannic of 1874 witi their 1G knots. The Steam Dressiire3 on orean Btpam. ers up to Ife'SO did not exceed 20 pounds. With the earlier vessels, with only i to 10 pounds of steam, it was possible to stop a leak in a boiler "by pushing a rag in the hole." As hue as 184G a prominent firm of engine builders ii? England stated that from 10 to 12 pounds was v;hat they used for merchant mer-chant vessels. By lbbO pressure had increased in-creased to from GO to S0 pounds, and on the introduction of steel for boilers pressures pres-sures went up to abuut 100 pounds by lbbo, and now boilers &re being built, for large steamers, to carry 200 pounds. Special types of boilers for torpedo boats and other uses cany muah hij her pressure. pres-sure. The Ericsson machinery weighs only 56 pounds per horsepower. This last ia for torpedo boats and nigh pressures and can not yet be approached for large vessels. On the trial trip the Minneapolis Minneapo-lis developed 20,812 horsepower, and the total weight of all tho machinery, with tho water in the boilers, was 1,06 J tons, so thac the weight of machinerj for each horsepower was about 210 pounds. Had the Minneapolis machinory been of the same relative weight a3 that of the Powhatan it would have weighed over 8,400 tons, or l,t00 tons more thac the Minneapolis herself weighed on ho? trial trip. Chautauquau. |