GAUGING WIDTH OF BROOK. 93 



current has its marks. Here, not far from the steep bank 

 is a flag, bowed or broken, whose pennant-Hke tongue of 

 green floats just beneath the surface, slowly vibrating to 

 and fro, as you wave your hand in token of farewell. 

 This is mark one — say three feet from the shore. 



Somewhat farther there is a curl upon the water, not 

 constant, but coming every few seconds in obedience to 

 the increase or decrease of the volume of the stream, 

 which there meets with some slight obstacle out of sight. 

 For, although the water appears level and unvarying, it 

 really rises and sinks in ever so minute a degree with a 

 rhythmic alternation. If you will lie down on the sward, 

 you may sometimes see it by fixing a steady gaze upon 

 the small circular cave where the gallery of a water-rat 

 opens on this the Grand Canal of his Venice. Into it 

 there rises now and again a gentle swell — barely per- 

 ceptible — a faint pulse rising and falling. The stream is 

 slightly fuller and stronger at one moment than another ; 

 and with each swell the curl, or tiny whirlpool, rotates 

 above the hidden irregularity of the bottom. If you sit by 

 the dam higher up the brook, and watch the arch of the 

 cataract rolling over, it is perhaps more visible. Every 

 now and then a check seems to stay the current moment- 

 arily : and at night, when it is perfectly still, listening to 

 the murmur of the falling water from a distance, under 

 the apple-trees in the garden it runs a scale — now up, 

 then down ; each variation of volume changing the 



