. The railroad and engineering journal . atthe dilTerences and irregularities observed are due to acci-dental causes. The variation of speed recorded here isin some cases due to differences of steam pressure, partlypurposely produced, and partly coming of the fact that itwas necessary to take steam as it could be obtained, andwas impracticable to secure steady pressure, and in otherinstances was due to the fact, afterward discovered, thatthe governor had been adjusted in such manner as to beslightly cramped, and thus deprived of its wonderful sen-sitiveness and accuracy, as before t
. The railroad and engineering journal . atthe dilTerences and irregularities observed are due to acci-dental causes. The variation of speed recorded here isin some cases due to differences of steam pressure, partlypurposely produced, and partly coming of the fact that itwas necessary to take steam as it could be obtained, andwas impracticable to secure steady pressure, and in otherinstances was due to the fact, afterward discovered, thatthe governor had been adjusted in such manner as to beslightly cramped, and thus deprived of its wonderful sen-sitiveness and accuracy, as before this defecthad been introduced, and after it had been records, made later by Prof. Anthony, ex-hibit the most extraordinary smoothness. These variations of speed served the useful purpose ofcalling attention to the fact that the engine-friction varied,at constant load and speed, with variation of steam pres-sure, and to a very noticeable amount, within the usualrange of pressures met with in practice. It is seen that. not in all respects satisfactory, indicated a slight increasein engine friction as steam pressures rose. The conclusionalready arrived at by the writer, as deduced from thework previously done, that the engine friction, in thisclass of steam-engine, is constant, or sensibly so, under allloads, is thus here again confirmed. The following arethe data obtained, arranged as before, to exhibit the re-lation of the indicated to the dynamometric powers: I. 2. 3. 4. 5. 6. 7. 8. Brake Ind. H. Press. ■965 H. P. percard. H. P. =3-73 »v6i » Press. 3-7< i: n 7 of the above The first glance at column 6 or at coltable, in which the horse-power absorbed by the frictionof the engine, and the mean effective pressure correspond-ing to that power are presented, shows that, as alreadyconcluded, the resistance of this class of engine at con- in rising from 19 to 76 pounds steam pressure, the pressuredemanded t
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Keywords: ., bookcentury1800, bookdecade1880, booksubjectrailroa, bookyear1887
