382 



SHELLS. 



[Chap. XL 



In the evening when the moon rose, I took a boat and 

 accompanied the fishermen to the spot. We rowed 

 about two hundred yards north-east of the jetty by the 

 fort gate ; there was not a breath of wind, nor a ripple 

 except those caused by the dip of our oars. On coming 

 to the point mentioned, I distinctly heard the sounds in 

 question. They came up from the water like the gentle 

 thrills of a musical chord, or the faint vibrations of a 

 wine-glass when its rim is rubbed by a moistened finger. 

 It was not one sustained note, but a multitude of tiny 

 sounds, each clear and distinct in itself ; the sweetest 

 treble mingling with the lowest bass. On applying the 

 ear to the woodwork of the boat, the vibration was 

 greatly increased in volume. The sounds varied con- 

 siderably at different points, as we moved across the 

 lake, as if the number of the animals from which they 

 proceeded was greatest in particular spots ; and occasion- 

 ally we rowed out of hearing of them altogether, until 

 on returning to the original locality the sounds were at 

 once renewed. 



This fact seems to indicate that the causes of the 

 sounds, whatever they may be, are stationary at several 

 points; and this agrees with the statement of the 

 natives, that they are produced by mollusca, and not by 

 fish. They came evidently and sensibly from the depth 

 of the lake, and there was nothing in the surrounding 

 circumstances to support the conjecture that they could 

 be the reverberation of noises made by insects on the 

 shore conveyed along the surface of the water ; for they 

 were loudest and most distinct at points where the na- 

 ture of the land, and the intervention of the fort and 

 its buildings, forbade the possibility of this kind of con- 

 duction. 



