[ 365 ] 

 LXIX. Proceedings of Learned Societies. 



GEOLOGICAL SOCIETY. 



[Continued from p. 309.] 



Dec. 1, A paper was first read, entitled, "Report of the Destruc- 

 1841. -t\. tion by Earthquake of the Town of Praya de Victoria, 

 on the 15th of June, 1841." By Mr. Consul Hunt; communicated 

 by direction of the Right Hon. the Foreign Secretary of State. 



't he town of Praya stood at the east end of the island of Terceira, 

 and contained 562 houses ; near it were the villages of Lageas (523 

 houses), Villa Nova (206 houses), Agoalva (244 houses), Fontinha 

 (203 houses), and Fonte do Bastardo (144 houses), the total popula- 

 tion being about 9000 souls. The town of Praya had been on a 

 former occasion (1614) totally destroyed by an earthquake, and 

 Angra, the capital of the island, situated twelve English miles 

 distant, was considerably injured, the shocks being severely felt 

 in the island of St. Michael. Although menaced during many 

 earthquakes, Praya had escaped injury from that time till the 12th 

 of June 1841, when, at 4 p.m., a violent shock was felt, and with 

 diminished force to the westward. At twenty-five minutes past 

 five, a second, more powerful shock was experienced, and through- 

 out the 13th of June, tremblings were felt at short intervals. At 

 4 a.m. on the 14th a perfectly perceptible undulation destroyed all 

 those buildings which had been previously weakened, but during the 

 remainder of that day the island was visited by only occasional slight 

 shocks. On the 15th, at 3 a.m., violent tremblings and horizontal 

 undulations of the ground commenced, and continued, with intervals 

 of ten minutes, and a duration of about 10 seconds, until 30 minutes 

 past 3 o'clock, when a strong, vibrating and distinctly visible rocking 

 motion was communicated to the surface, and threw down the un- 

 destroyed portion of Praya, several churches and houses of the adja- 

 cent villages, and considerably injured the remainder, as well as 

 many elevated public buildings in other parts of the island. The 

 ground then remained comparatively at rest until 40 minutes past 2 

 a.m. on the 16th, when a violent earthquake did further damage; 

 but from that period no additional injury was sustained, though the 

 island did not resume a permanently quiescent state till the 26th of 

 June. The number of houses thrown down is estimated to be 800, 

 but several others must be rebuilt, and of the remainder the greater 

 number require extensive repairs. 



During the whole of these earthquakes the motion was greatest at 

 Praya, diminishing in force to the westward, and every convulsion 

 was preceded by a loud subterranean or submarine noise to the east- 

 ward of Terceira, which so exactly varied in intensity with the force 

 of the succeeding shocks, that the noise became not only the harbinger 

 but the measure of the severity of the earthquake. A rent an English 

 mile in length was formed in the ground, extending from the shore 

 to the westward. 



The less severe shocks were not felt beyond Terceira : others were 



