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POPULAR SCIENCE REVIEW. 
—a place half way down the east coast of this island — he 
made some inquiries about certain sounds “resembling the 
faint sweet notes of an iEolian harp,” which were alleged to 
proceed from the bottom of a neighbouring lake. The fisher- 
men said that both they and their fathers knew of these sounds, 
which were declared to be audible during the dry season, but to 
cease when the lake had been swollen after the rains. These, 
they said, proceeded not from a fish, but from two species of 
mollusc (a Littorina and a Cerithium ), known by the Tamil 
name of oorie coolearo cradoo , or the “ crying shell.” * Sir E. 
Tennent took a boat and visited the lake by moonlight, and 
thus describes the sounds which he heard: — “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 considerably at different points, 
and could be localised, as it was possible to row away out of 
their influence. This fact, thought Sir E. Tennent, lends support 
to the view of the fishermen, that the sounds were produced by 
molluscs and not by fish. Similar sounds have been heard in 
the harbour of Bombay ; described as “ like the protracted 
booming of a distant bell, the dying cadence of an ^Eolian harp, 
the note of a pitch-pipe or pitch-fork, or any other long-drawn- 
out musical note.” These sounds came from all directions, 
almost in equal strength, and arose from the surface f of the 
water all round the vessel. The fish which was alleged to pro- 
duce these sounds closely resembled in size and shape the fresh- 
water perch of the north of Europe. These phenomena were 
carefully observed and noted by a party of five intelligent 
persons. 
The “ Magoora ” — a fish found in the lake at Colombo — is 
stated by the fishermen to make a grunt when disturbed under 
water ; and a certain flat-fish in Siam, according to Pallegoix, 
“ fait entendre un bruit tres sonore et meme harmonieux.” 
At Caldera, in Chili, at the mouth of the Pascagoula, in the 
Mississippi State, and of the “ Bayon coq del Inde ” river on 
* It is known, from the observations of the late Prof. Grant, that one at 
least of the gasteropodous molluscs ( Tritonia orborescens ) has the power of 
producing sounds — apparently by the mouth, which is armed by two horny 
plates — so that it is possible that the sounds in question were really pro- 
duced by molluscs; a point on which Sir E. Tennent was not able to 
satisfy himself. 
t It should be noted that the sounds heard by Sir E. Tennent “ came 
evidently and sensibly from the depth of the lake.” 
