. Factory and industrial management. sixty to sixty-twoper minute with exactly the same consumption of coal by running theblowers gently on the closed ash-pit system as against natural men enjoyed this plan, and the steam pressure could be keptmuch more uniform than under plain natural draught. All personsinterested in the great Transatlantic steamers must have noticed thatin the last ten years there has been a tendency to use funnels whichare much higher than formerly. The first vessel to adopt this methodof increasing the draught was the steamship Scot, of the line runningto the
. Factory and industrial management. sixty to sixty-twoper minute with exactly the same consumption of coal by running theblowers gently on the closed ash-pit system as against natural men enjoyed this plan, and the steam pressure could be keptmuch more uniform than under plain natural draught. All personsinterested in the great Transatlantic steamers must have noticed thatin the last ten years there has been a tendency to use funnels whichare much higher than formerly. The first vessel to adopt this methodof increasing the draught was the steamship Scot, of the line runningto the Cape of Good Hope. This, of course, is simply adapting tosteamers what had been the practice for many years on shore, wheretall chimneys had been the rule. For naval vessels this has the addedadvantage of increased cleanliness, because with the tall funnels theparticles of dust and soot are carried clear of the ship, while with theshort funnels they are likely to dirty the after decks. The Brooklyn was 4o6 THE ENGINEERING THE PROTECTED CRUISER KAISEKIN AUGUSTA, OF THE GERMAN at Kiel. 1892. 388 by 49^ by 23 feet, 6,300 tons displacement; ij,ooo indicated liorsepower (forced dratiglit), knots. Like the Minneapolis and the Columbia, shehas triple screws driven liy three triple-expansion engines. Steam is fur-nished by eight double-ended cylindrical boilers. the first of the American vessels to have these tall funnels, but sincethen it has been common practice. Roughly speaking, each additionalten feet of height in the funnel increases the draught by an amountequal to an air pressure of one-eighth of an inch of water, so that anadditional forty feet of height would be the equivalent of about halfan inch of air pressure. In the case of the Brooklyn it was esti-mated that this (half an inch air pressure) would be equivalent toan increase of power sufficient to raise the speed from about sixteenknots to seventeen and one-half knots. It should be noted that t
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