Читать книгу Locomotive Engine Running and Management онлайн

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The highest type of fireman is one, who, with the smallest quantity of fuel, can keep up a good head of steam without wasting any by the safety-valves. He endeavors to strike this mean of success by keeping an even fire; but it sometimes happens, that the closest care will not prevent the steam from showing indications of blowing off. When this is the case, he keeps it back by closing the dampers, or, if that is not sufficient, opens the door a few inches. Immense harm is done to flues and fire-boxes by injudicious firing.

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It is not necessary that a man should be deeply read in natural philosophy, to understand intimately what are actually the scientific laws of the business of firing. Mr. Lothian Bell, the eminent metallurgist, somewhere expresses high admiration for the exact scientific methods attained in their work by illiterate puddlers. Although they knew nothing about chemical combinations or processes, they manipulated the molten mass so that, with the least possible labor, the iron was separated from its impurities. In a similar way, firemen skillful in their calling have, by a process of induction, learned the fundamental principles of heat-development. By experiments, carefully made, they perceive how the greatest head of steam can be kept up with the smallest cargo of coal; and they push their perceptions into daily practice.