Elements of Natural Philosophy: Embracing the General Principles of Mechanics, Hydrostatics, Hydraulics, Pneumatics, Acoustics, Optics, Electricity, Galvanism, Magnetism, and Astronomy |
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angle appear atmosphere attraction axis ball bottom called centre of gravity centrifugal force circle colours comet concave constellations convex convex lens copper cylinder Describe diameter direction distance diurnal motion Earth eclipse effect elastic electricity equal equator equinox experiment fall feet figure fixed stars fluid focus force Give the illustration glass globe heavenly bodies heavens hence Herschel horizon inches inclined inclined plane length lens less lever liquid luminous lunar eclipse machine magnet means Mercury meridian metal miles mirror Moon motion move object oblique Observation opposite orbit passing perpendicular pipe piston planet plate pole position pressure principle produced pulley rays of light reflected reflecting telescope refraction represented retina revolution revolve rise seen side solar solar eclipse space specific gravity Sun's supposed surface telescope tides tion tube valve velocity Venus vessel vibrations weight wheel wire wood-cut zinc
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Page 240 - ... can be raised higher than another. The Mediterranean and Baltic seas have very small elevations, because the inlets by which they communicate with the ocean are so narrow, that they cannot, in so short a time, either receive or discharge enough, sensibly to raise or sink their surfaces.
Page 119 - If the candle be placed farther from the glass than its focal distance, the rays will converge after passing through the glass, and meet in a point which will be more or less distant from the glass, as the candle is nearer to, or farther from, its focus...
Page 38 - These simple machines are the lever, the wheel and axle, the pulley, the inclined plane, the wedge, and the screw.
Page 71 - The capability of breathing freely and at regular intervals is essentially requisite to enable a person to support himself on the surface of water. The head, and the upper and lower extremities are relatively heavier than the trunk of the human body ; and the head especially, from the quantity of bone of which it is composed, is the heaviest part of the whole mass, yet unless the face at least be kept above water respiration cannot be continued. It is therefore of the highest importance that all...
Page 236 - ... side, seems, to many, palpably absurd. Yet nothing is more true, nor indeed more evident, when we consider that it is not by her whole attraction, but by the differences of her attractions at the opposite surfaces and at the centre, that the waters are raised.
Page 207 - The Azimuth of a heavenly body, is the arc of the horizon intercepted between...
Page 57 - E, while it both descends and ascends in F, rising equally in all the tubes, and spouting out till the water is reduced in the side tubes to the level of the summits of the internal ones, when the equilibrium being established the liquid will remain at rest. Thus it follows that any number of columns of a liquid, freely communicating, whatever may be their respective diameters and figures will always have the same vertical height.
Page 129 - The following definitions apply equally to concave and convex mirrors: The middle point of the mirror is called its vertex. The centre of the sphere, of which the mirror forms a part, is called the optical centre.
Page 31 - I shall just offer a few illustrations of the CENTRE OF GRAVITY. The centre of gravity of a body is that point about which all its parts...
Page 186 - A circle is a plane figure bounded by a curved line called the circumference, every point of which is equally distant from a point within called the center, Fig.