Echoes In Mammoth Cave

Our guide asks us to Keep sneni; then, lifting the heavy, broad paddlo with which he has been propelling our boat, he strikes with all hls strength the flat side on the surface of the water. Instantly the subterranean thunders of this under-world are let loose. From all directions come rolling waves of sound, multiplied a thousandfold, receding, and again returning with increasing volume, lingering for many seconds, and finally dying away in sweet, far-away melodies. Then, when the last faint sounds have ceased, he agitates the water with his paddie, and asks us to listen. The receding waves, reaching cavitiies in the sides of the overhanging arches, break the stillness with sweet bell-like sounds. Some notes, striking the key-note of the rocks, multiply the musical nielody; some notes are soft and low; others are loud, almost with an alarm-bell clangor. This music, such as cannot be heard elsewhere on earth, gradually dies away in receding echoes, coming over the waters from far-away hidden chambers. The echo is not such as we hear above ground or in buildings, but a succession of receding waves of sound, lasting for about thirty seconds, and adding an indescribable melody to all sounds, whether from shouting or from instrumental or vocal music. - "The Mammoth Cave of Kentucky," by John R. Proctor, in the Century.