32t> SOCND. 



, . * 



in the neighborhood of Rouen. A person who sings, 

 does not hear the repetition of the echo, but merely his 

 own voice ; while those who listen hear only the repeti- 

 tion of the echo, though \v ith singular variations. Some- 

 times the echo seems to approach, and at other times to 

 recede. One person hears a single voice, and another 

 several voices : one person hears the echo on the right, 

 and another on the left; the echo always varying with 

 the position of the person who hears it. 



M. duesnet has described another singular echo near 

 Rouen, in the Memoirs of the Academy for 1664. 



In the neighborhood of Coblentz, on the banks of 

 the Rhine, there is a very remarkable echo, which is 

 described by Barthius, in his notes upon the Thebaid of 

 Statius. He has heard it repeat words seventeen times, 

 and it produces exactly the same effects as. that at 

 Genefay, near Rouen. 



At Lochencilan, a lake in Invernesshire, and the 

 property of J. P. Grant, Esq. of Rothiemurehus, there is 

 a very fine echo. The wall of an old castle, in the mid- 

 dle of the lake, repeats several syllables with great dis- 

 tinctness ; and when a pistol is fired, the sound is repeated 

 about thirty times, from the numerous and lofty hills with 

 which the lake is encircled. 



In the neighborhood of Edinburgh, in the King's 

 Park, there is a place called the Echoing Rock. A per- 

 son standing in front of this will hear repeated with great 

 distinctness several syllables which he may utter. The 

 sound in this case is reflected from a circular wall at no 

 great distance, and the rock to which the property is 

 ascribed merely happens to be near the centre of the cir- 

 cular wall. 



In erecting the baptistry of the church of Pisa, the 

 architect, Giovanni Pisano, disposed the concavity of the 

 cupola in such a manner, that any noise from below is 

 followed with a very loud and long double echo. The 

 repetition, however, is not so distinct as that of Simonetta. 

 Two persons whispering, and standing opposite to each 

 other, with their faces near the wall, can converse to- 

 gether without being overheard by the company between. 

 This arises from the elliptical form of the cupola, each 

 person being placed in the focus of the ellipse. 



