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ONE:To follow the same chain of reasoning still farther, and to show what may be gained by method and system in learning mechanics, it may be assumed that machine functions consist in the application of power, and therefore power should be first studied; of this there can be but one opinion. The learner who sets out to master even the elementary principles of mechanics without first having formed a true conception of power as an element, is in a measure wasting his time and squandering his efforts.So far as he could see there were no signs of dust or desolation about the corner house. The hall was clean and bright, there was a thick carpet on the stairs. Every door was shut save one on the first floor, into which the fair beauty with the lovely hair led the way. Four or five gas jets were flaring away with a hissing roar. A draught from somewhere made them flicker restlessly on a large room absolutely devoid of furniture save for an old-fashioned four-post bedstead in the middle. The air was close and stuffy, as if the window had not been opened for months. There were barred shutters before them.