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action aerial agitated atmosphere audible augmented beats bell burner carbonic acid caused centre column of air condensation corresponding density direction disc distance divides echoes effect elasticity embouchure Eustachian tube experiments fork fundamental tone gases glass hear heard heat Helmholtz Hence hydrogen inches instrument intensity interval John Herschel law of superposition layers length light liquid longitudinal membrane ment miles Montlhery motion musical sound nodal lines nodes number of vibrations observed obtained octave optical organ-pipe orifice oscillation overtones particles pass pendulum pitch placed plate pressure produced prongs puffs pulse rapidity rarefaction rate of vibration ratio reed reflected rendered resonance resultant tone rotation screen sensitive flame sonorous wave sound-wave South Foreland square stretched string surface syren temperature tion Trinity House tube tuning-fork tympanic membrane unison vein velocity of sound ventral segments vibrating segments Villejuif whistle wire
Página 366 - ... into unisonant vibration. 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.
Página 69 - Glaciers of the Alps ' I have referred to a case of short auditory range noticed by myself in crossing the Wengern Alp in company with a friend. The grass at each side of the path swarmed with insects which, to me, rent the air with their shrill chirruping. My friend heard nothing of this, the insect-music lying quite bej'ond his range of audition.
Página 51 - A musical sound is produced when the tympanic membrane is struck periodically with sufficient rapidity. The production of these tympanic shocks by puffs of air was first realized by Dr.
Página 366 - 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 unisonant vibration.
Página 403 - But there is no mention of any interval ; and had such existed, surely the word " followed," instead of " accompanied," would have been the one employed. The echoes, moreover, appear to have been continuous, while the clouds observed seem to have been separate. " Ces phenomenes," says Arago, " n'ont jamais eu lieu qu'au moment de 1'apparition de quelques nuages." But from separate clouds a continuous roll of echoes could hardly come. When to this is added the experimental fact that clouds far denser...
Página 234 - The slightest tap on a distant anvil reduces its height to 7 inches. When a bunch of keys is shaken the flame is violently agitated, and emits a loud roar. The dropping of a sixpence into a hand already containing coin, at a distance of 20 yards, knocks the flame down.
Página 32 - ... the ratio of the specific heat of air at constant pressure to the specific heat at constant volume.
Página 234 - 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.
Página 76 - The lower end of the rod rests upon the sound-board of the piano, its upper end being exposed before you. An artist is at this moment engaged at the instrument, but you hear no sound. I place this violin upon the end of the rod; the violin becomes instantly musical, not however with the vibrations of its own strings, but with those of the piano.
Página 40 - As to the motion of the parts one amongst another, to their becoming sensible, they require either that their motions be increased, or that the organ be made more nice and powerful to sensate and distinguish them as they are ; for the doing of both which I think it is not impossible but that in many cases there may be helps found.