A Compendium of Natural Philosophy: Adapted to the Use of the General Reader, and of Schools and Academies

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S. Babcock, 1842 - Physics - 360 pages
 

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Page 201 - In the present perfect state of the engine it appears a thing almost endowed with intelligence. It regulates with perfect accuracy and uniformity the number of its strokes in a given time, counting or recording them, moreover, to tell how much work it has done, as a clock records the beats of its pendulum ; it regulates the quantity of steam admitted to work; the briskness of the fire; the supply of water to the boiler ; the supply of coals to the fire ; it opens and shuts its valves with absolute...
Page 201 - Its aliment is coal, wood, charcoal, or other combustible ; it consumes none while idle ; it never tires, and wants no sleep ; it is not subject to malady when originally well made, and only refuses to work when worn out with age ; it is equally active in all climates, and will do work of any kind ; it is a water-pumper, a miner, a sailor, a cotton-spinner, a weaver, a blacksmith, a miller, &c.
Page 148 - Mountains, the loftiest in the world, at the distance of eighteen hundred miles from its mouth, is only eight hundred feet above the level of the sea, — that is, about twice the height of St. Paul's church in London ; and to fall these eight hundred feet, in its long course, the water requires more than a month. The great river Magdalena, in South America...
Page 139 - When the pipe AD is filled with water, the pressure upon the surface of the bellows, and consequently the force with which it raises the weights laid on it, will be equal to the weight of a cylinder of water, whose base is the surface of the bellows, and height that of the column AD. Therefore, by making the tube small, and the bellows large, the power of a given quantity of water, however small, may be increased indefinitely. The pressure of the column of water in this case corresponds to the force...
Page 323 - ... scrutiny ; for, however anatomists may differ on points of structure, or physiologists dispute on modes of action, there is that in what we do understand of the formation of the eye so similar, and yet so* infinitely superior, to a product of human ingenuity, — such thought, such care, such refinement, such advantage taken of the properties of natural agents used as mere instruments, for accomplishing a given end, as force upon us a conviction of deliberate choice and premeditated design, more...
Page 100 - The pulley is a small wheel, movable about its axis by means of a cord, which passes over it. When the axis of a pulley is fixed, the pulley only changes the direction of the power ; if movable pulleys are used, an equilibrium is produced, when the power is to the weight, as one to the number of ropes applied to them.
Page 70 - Powers, are certain simple instruments, commonly employed for raising greater weights, or overcoming greater resistances, than could be effected by the natural strength without them. These are usually accounted six in number, viz. the Lever, the Wheel and Axle, the Pulley, the Inclined Plane, the Wedge, and the Screw.
Page 156 - ... the effect, therefore, of overshot wheels, under the same circumstances of quantity and fall, is at a medium double to that of the undershot ; and, as a consequence thereof, that non-elastic bodies, when acting by their impulse or collision, communicate only a part of their original power ; the other part being spent in changing their figure, in consequence of the stroke.
Page 10 - M any cause which moves or tends to move a body, or which changes or tends to change its motion.
Page 106 - ... case, were it not for the friction, they would recoil from their places, and fail to produce the desired effect. Even when the wedge is used as a mechanical engine, the presence of friction is absolutely indispensable to its practical utility. The power...

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