And, when it chanced 
That pauses of deep silence mocked his skill, 
Then, sometimes, in that silence, while he hung 
Listening, a gentle shock of mild surprise 
Has carried far into his heart the voice 
Of mountain torrents ; or the visible scene 
Would enter unawares into his mind 
With all its solemn imagery, its rocks, 
Its woods, and that uncertain heaven, received 
Into the bosom of the steady lake. 
