Stationary steam engines, simple and compound; especially as adapted to light and power plants . urfaces to which it is exposedon all sides at the beginning of the stroke. One of themethods of securing this economy in the working of steam,has been stated to-be the driving of the engine up to thehighest safe velocity of piston, and giving it a maximumspeed of rotation. The time allowed for condensation ofeach charge, and for the necessary change of temperaturepreceding such condensation, is thus reduced, and theamount of steam condensed being thus made a minimum,in any given time, the percentag
Stationary steam engines, simple and compound; especially as adapted to light and power plants . urfaces to which it is exposedon all sides at the beginning of the stroke. One of themethods of securing this economy in the working of steam,has been stated to-be the driving of the engine up to thehighest safe velocity of piston, and giving it a maximumspeed of rotation. The time allowed for condensation ofeach charge, and for the necessary change of temperaturepreceding such condensation, is thus reduced, and theamount of steam condensed being thus made a minimum,in any given time, the percentage of loss of the increasedquantity of steam worked off by the engine becomes theleast possible. The engine does a greater amount of work,and is subject to less loss. Thus the work to be done beingfixed, it is done by a smaller, and, other things being equal,a less costly engine, and at the same by a more economicalmachine. Although this seems a sufficiently simple and axiomaticphilosophy, and although the general tendency of practicein steam engineering had been plainly in this direction for. w %\ ELECTRIC LIGHTING PLANTS. 55 many years, these points had not, up to a comparativelyrecent time,been recognized by constructing engineers, andtheir progress had been slow and difficult. The older firmswho were engaged in the building of what were then calledexpansion engines, were the first to detect this movementand its cause, and they led off, in a very conservative way,toward the construction of faster engines. The firmsalready mentioned as leading in the movement toward cor-rect practice, came up to speeds far ahead of those commonamong other makers, and secured an advantage that wassufficient to prove unmistakably that they were in the righttrack. They did not, however, modify their designs in anygreat degree, with a view to adapting them to very highspeeds. Their valve-gears were not of a kind wellfitted to high speed of rotation; the builders, were them-selves disinclined to ac
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectsteamen, bookyear1902
