The Song of the Lark.
Above our heads, almost invisible, poises a lark, singing his “ profuse strains of unpremeditated art.” The tuneful speck is half a mile above us, yet every note and trill falls clear and sweetly on the ear. The little vocal cords within his throat, which constitute his lyre, are scarce a third of an inch in length ; yet their vibration fills the air with melody. On every side for half a mile his song is heard, and thus he fills a sphere of air a mile in diameter with music. Music, and indeed all sound, is the effect produced upon our ears by vibrations or tremors of a certain frequency. Hence every particle of air in the mile-wide sphere is pulsating in unison with the lark’s small vocal cox'ds. A cubic foot of air at this time of the year weighs about 400 grains, and the number of cubic feet which are taking up the song amount to tens of thousands of millions. Ho\v is this stupendous result brought about by such apparently inadequate means I The answer is simple. When the vooal cords in the throat of tho lark ■are set vibrating like harp-strings, the of air in contact therewith are violently driven forward, and by their (elasticity spring back again to their ori-
j ginal position. During their forward motion they impinge upon the particles of air in front of them, which are in consequence similarly driven forward, and in like manner recover themselves by virtue of their elasticity. This is continued, each particle driving its neighbour forward and then returning to its former station. It thus appears that while every particle of air swings to and fro over a very small space, the pulsation or vibration is carried onwards and outwards in every direction. Finally, the throbbing particles reach our ears, and impinging upon a beautiful apparatus therein, yield up their motion, which is carried on to the brain, where it produces the sensation of sound.
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The Song of the Lark., Ashburton Guardian, Volume I, Issue 4, 4 October 1879
The Song of the Lark. Ashburton Guardian, Volume I, Issue 4, 4 October 1879
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