BROOK TROUT 



The impact of the hurrying water on the air causes 

 vibrations that determine the notes of the liquid 

 oboe. 



When deflected from a bank in mass, the water has 

 the swishing sound of swift volume — crisp and full of 

 life. Confined and made rapid in a little canon or cut, 

 its tone is deepened and becomes sonorous. 



Or it falls over a half buried timber and deepens to 

 a low roar, which is slashed with purling dots of sound 

 as drops fall singly into the current. From underneath 

 this shell of swift water come echoes of partly drowned 

 inotes from the back-current below, and purls from 

 !roots and boughs around which the turned stream hur- 

 ries. Gurgles ensue — the compressed air below vary- 

 ing in density with the varying volume of the water- 

 leaps, the tones of the back-flow struggling through, 

 with the whisper of air intermingled as it comes from 

 the breaking bubbles with which the boiling pool is 

 brightly opaque. 



Or a fallen tree with its hundreds of boughs and 

 twigs forms obstructive points of sounding current — 

 tiny, but the whole furnishing a low, droning com- 

 plaint. All these notes are varied by the width of 

 stream, volume, depth, speed, angles of obstruction, 

 character of the bed, kind, amount, and density of foli- 

 age, incline and height of banks, changes in echoes 

 and resonance being endless, and even being affected 

 by the dryness or humidity of the air, and the ming- 

 ling of foliage sounds as winds are light or strong. 



178 



