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Show gtfparacwjM.11 kit iJJi-wiiwonr3paaqwpwac3oaCTcaBiiattbggg 7Hft MOUERN 8TEAM6HIP. fmpo&dble to Guess "Vhat Speed May Iffi! Be Keaclicd Ilereafter. Twenty years ago it -svas thought by many thnt th6 limit as to size, speei and economy had been reached. At pres ant it seems that the draft of water at the harbors and tho cost are the limits that will prevent further development on piesent lines. With different material ma-terial for consn notion, 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. G knots as we look back on thf Germanic and Britannio of 1874 with their 1G knots. The steam pressures on ocean steamers steam-ers up to 1850 did uot exceed 20 pounds. With the earlier vessels, with only 3 to 10 pounds of steam, it was possible to stop a leak in a boiler "by pushing 8 rag in 'the hole." As late as 1SJG a prominent firm of engine builders ir England stated that from 10 to 18 pounds was what they used for merchant mer-chant vessels. By 1880 pressure had increased in-creased to from GO to 90 pounds, and on tho introduction of steel for boilers pressures pres-sures went up to about 100 pounds by 1885, and now boilers ate boinj built, for large steamers, to carry 200 pounds. Special types of boilers for torpedo boats ana otner uses carjy inuon nia'uer pressure. pres-sure. The -Ericsson machinery weighs only 50 pounds per horsepower. This last i for torpedo boats and high pressmes and can not yet bo approached for large ressols. On tho trial trip the jilinneapo 1 lis developed 20,812 horsepower, and the total weight of all tho machinery, with the water in tho boilers, was 1,9(51 tons, so that the weight of machinery for each horsepower was about 210 pounds. Had the Minneapolis machinery been of tho samo relative weight as that of tho Powhatan it would have weighed over 8,400 to?s, or 1,000 tons more than tho Minneapolis horself weighed on lies fciial trip, Chautauquan. |