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action air-pump angle aperture apparatus appear applied ascertained atmosphere atmospheric pressure attraction ball become bodies cause centre of gravity centrifugal force circumstances colours common compressed concave construction convex convex lens cylinder degree density depend described diameter direction distance earth effect elastic electricity equal exhibited experiments Fahrenheit fall feet figure fluid force friction gases glass glottis heat Hence hydrostatic pressure inches inclined plane instrument latter length lens lenses lever light liquid machine magnetic manner mass means mercury metal mirror motion moving Natural Philosophy nature object observed pass peculiar pendulum phenomena philosophers piston plane plate pole pounds pressure principle produced proportion pyrometer quantity rays reflected refraction relative retina screw side solid sound space specific gravity string substances supposed surface takes place temperature thermometer tion tone tube valve velocity vertical vessel vibrations voltaic pile weight wheel wire zinc
Page 28 - Every body continues in its state of rest, or of uniform motion in a straight line, unless it is compelled to change that state by forces impressed upon it.
Page 491 - We have great pleasure in directing the attention of our readers to this little work . . . bearing as it does on one of the most important aspects of physiological medicine, as well as on education in the highest sense of the word.
Page 490 - been the influence of the reformation of Luther, on ' the political situation of the different states of Europe, 'and on the progress of knowledge?
Page 237 - Grylli (crickets or grasshoppers), whose powers appear to commence nearly where ours terminate, may hear still sharper sounds, which we do not know to exist ; and that there may be insects hearing nothing in common with us, but endued with a power of exciting, and a sense that perceives the same vibrations .which constitute our ordinary sounds, but so remote that the animal who perceives them may be said to possess another sense, agreeing with our own solely in the medium by which it is excited,...
Page 439 - Thus, in a battery composed of zinc, diluted sulphuric acid, and copper, the acid acts upon the zinc, and not on the copper. The galvanic fluid proceed, therefore, from the zinc to the acid, from the acid to the copper, &c.
Page 385 - What relation has colour to refraction ? the eye, the objects seen through it will not be doubled, as when viewed directly through one of the flat sides of the glass, but they will be more or less elongated, according to the angle at which the prism is held, and will also be clothed with all the colours of the rainbow. Violet Indigo Blue Green Yellow Orange Red White 161. The dissection of a ray of solar light into different colours, by refraction, may be more accurately displayed by admitting a...
Page 43 - This decrease of weight, in proportion to the squares of increasing distances', might in some situations be made the subject of experiment. A ball of iron, weighing a thousand pounds at the level of the sea, would be perceived to have lost two pounds of its weight, as ascertained by a spring balance, if taken to the top of a mountain four miles high. The same body removed from Edinburgh to the north pole would gain the addition of three pounds; and if conveyed to the equator, it would suffer a loss...
Page 217 - Now when the piston is at the bottom of the barrel, the pressure of the atmosphere on the surface of the water in the well...
Page 174 - It consists, as is shown in the annexed, figure, of a wheel on the periphery of which are fixed a number of flat boards at equal distances, and set at right angles to the plane of the wheel. They are called float-boards ; and the wheel being so placed as for its lowest point to be immersed in flowing water, it is set in motion by the impact of the water on the boards as they successively dip into it. As a wheel of this kind will revolve in any stream which furnishes a current of sufficient power,...