GEOLOGICAL SOCIETY OF LONDON. 



45 



ones, nature having doubtless thus given a sUght compensa- 

 tion of internal volume. Thus the difference of the sexes 

 may cause a greater or less compression of the shelly approxi- 

 mation or separation of the ribs and tubercles^ render them 

 more numerous on a whorl, and sometimes change the rela- 

 tive size of the last whorl to the whole diameter. 



(To he continued.) 



PROCEEDINGS OP SOCIETIES. 



GEOLOGICAL SOCIETY OF LONDON. 



Wednesday^ 1st December^ 1841. — R. J. Murchison, 

 Esq. President in the chair. The following papers were 

 read, viz.: 



" An account of the destruction of the town of Pray a de 

 Fictoria in the island of Terceira on the \5th June^ 1841." 

 By J. Carew Hunt, Esq., Consul, communicated by the Earl 

 of Aberdeen. 



" The town of Praya was situate at the east end of Terceira, and 

 consisted of 562 houses. Since 1614, when Angra (the capital of the 

 island) was damaged and this town totally destroyed, it had sustained no 

 injury from earthquakes, although several had been felt. On the 12th 

 June 1841, at 4 p. m. and at 20 m. past 5 p. m., violent shocks were 

 felt at Praya, as also during the whole of the 15th. At 4 p. m. on the 14th, 

 an undulation of the ground was perceived which threw down several 

 houses. During the remainder of the day the island was undisturbed, 

 save by a few slight shocks, but at 3 p. m. on the 15th violent trem- 

 blings accompanied by horizontal movements commenced, and conti- 

 nued at intervals of ten minutes till half past 3, when a strong vibratory 

 motion destroyed every building which had escaped, as well as seve- 

 ral houses and public buildings in other parts of the island. The 

 ground remained comparatively at rest till 20 minutes to 3 p. m. on the 

 l6th, when another violent shock was experienced, and since that pe- 

 riod no further damage has been done, although the island did not re- 

 sume a permanently quiet state till the 26th June. The effects were 

 felt most violently at Praya. Mr. C. Hunt infers, that the shocks having 



