"A soft and lulling sound is heard Of streams inaudible by day."And Tennyson, in the valley of Cauteretz, tells of the river "Deepening his voice with deepening of the night."It is in this mystical hour that you will hear the most celestial and entrancing of all bird-notes, the songs of the thrushes,--the hermit, and the wood-thrush, and the veery. Sometimes, but not often, you will see the singers. I remember once, at the close of a beautiful day's fishing on the Swiftwater, I came out, just after sunset, into a little open space in an elbow of the stream. It was still early spring, and the leaves were tiny. On the top of a small sumac, not thirty feet away from me, sat a veery. I could see the pointed spots upon his breast, the swelling of his white throat, and the sparkle of his eyes, as he poured his whole heart into a long liquid chant, the clear notes rising and falling, echoing and interlacing in endless curves of sound, "Orb within orb, intricate, wonderful."Other bird-songs can be translated into words, but not this. There is no interpretation. It is music,--as Sidney Lanier defines it,--"Love in search of a word."