Collier, 1905 - 480 páginas

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Página 105 - It is curious to observe the change of feeling manifested by various individuals of the party, in succession, as the sounds approach and pass the limits of their hearing. Those who enjoy a temporary triumph are often compelled, in their turn, to acknowledge to how short a distance their little superiority extends.' ' Nothing can be more surprising...
Página 34 - ... you ought to see the particles separated more widely apart. You ought, in short, to be able to seize the conception that a sonorous wave consists of two portions, in the one of which the air is more dense, and in the other of which it is less dense than usual. A condensation and a rarefaction, then, are the two constituents of a wave of sound...
Página 426 - Within the ears of men, and without their knowledge or contrivance, this lute of 3,000 strings has existed for ages, accepting the music of the outer world, and rendering it fit for reception by the brain. Each musical tremor which falls upon this organ selects from its tensioned fibres the one appropriate to its own pitch, and throws that fibre into uniaonant vibration.
Página 426 - And thus, no matter how complicated the motion of the external air may be, these microscopic strings can analyse it, and reveal the constituents of which it is composed. Surely, inability to feel the stupendous wonder of what is here revealed would imply incompleteness of mind ; and surely those who practically ignore or fear them must be ignorant of the ennobling influence which such discoveries may be made to exercise upon both the emotions and the understanding of man.
Página 465 - ... effectual, was shifted to C, where its action on the screen was greatly augmented, it ceased to have any action on the flame at A. "We are now, I think, prepared to consider the failure of reversibility in the larger experiments of 1822. Happily an incidental observation of great significance comes here to our aid. It was observed and recorded at the time that while the reports of the guns at Villejuif were without echoes, a roll of echoes, lasting from 20 to 25 seconds, accompanied every shot...
Página 76 - ... here the density being diminished, the elasticity remains the same. The velocity is directly proportional to the square root of the elasticity of the air, and inversely as the square root of the density. Sound, in fact, travels through different media with very different degrees of velocity; thus, starting with air as unity or one, the following velocities have been determined: Distilled water...
Página 21 - ... arises from the fact that the signal often appears to be surrounded by a belt, varying in radius from one to one and a half miles, from which the sound appears to be entirely absent. Thus, in moving directly from a station, the sound is audible for the distance of a mile, is then lost for about the same distance, after which it is again distinctly heard for a long time.
Página 450 - ... separated by an interval of a fifth. " Thus, dividing his string at different points, Pythagoras found the so-called consonant intervals in music to correspond with certain lengths of his string ; and he made the extremely important discovery, that the simpler the relation of the two parts into which the string was divided, the more perfect was the harmony of the two sounds.
Página 464 - ... here visible from the reed ; hence the necessity of the foregoing experiments to prove the action of the sound on the upper portion of the flame to be nil, and that the waves had really to bend round the edge of the screen so as to reach the seat of sensitiveness in the neighbourhood of the burner. The positions of the flame and reed were reversed^ the latter being now close behind the screen, and the former at a distance of 6 feet from it.
Página 286 - Her ivory forehead full of bounty brave, Like a broad table did itself dispread, For Love his lofty triumphs to engrave, ' And write the battles of his great godhead : All good and honour might therein be read; For there their dwelling was.

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