Prorft'iliiiijK. Ixxi 



and Poiiipcii, had been pi'eccdcd by a great cartliquako. But tlic 

 occurrence of earthquakes could never be foretold. Tliey were, 

 however, by no means exceptional phenomena ; in fact they 

 were very common, and during the last twenty years there had 

 been no fewer tlian 8000, of which Great Britain had expe- 

 rienced 75. In Japan there was an average of one earthquake a 

 day, but many of tliem were only perceptible by delicate instru- 

 ments. Mr. Topley then proceeded to observe that earthquakes 

 were preceded by slight tremors, which were generally considered 

 to be the origin of the noise which accompanied them; then 

 followed the shock. Accounts of earthquakes were often greatly 

 exaggerated. A friend of his in the Riviera described the hotel 

 in which he was staying at Nice at the time of the recent 

 earthquake, on the 22ud of February, as having been lifted two 

 feet vertically, whereas if it had been raised a single inch 

 probably the entire building would have been overthrown, and a 

 lift of 0-1 inch would have upset all the chimney-pots. It was 

 believed that the majority of earthquakes originated at no great 

 depth below the surface, probably some seven or eight miles. 

 The region of greatest damage to buildings was not immediately 

 over the focus, when the shock was vertical, but at some distance 

 from it, when the emergent shock struck their foundations at an 

 angle. Mr. Topley then remarked that some earthquakes might 

 perhaps be attributed to the falling in of large blocks of lime- 

 stone in caverns hollowed out in limestone strata by the action 

 of water, producing a disturbance on the surface of the earth. 

 Earthquakes having their origin under the ocean gave rise to 

 enormous sea-waves. The disastrous effects of the earthquake 

 at Lisbon in May, 1755, had been greatly aggravated from this 

 cause ; and on the 13th of August, 18G8,the whole Pacific coast 

 of South America was subjected to a succession of vast ocean 

 rollers from the same cause. Mr. Topley then considered the 

 most suitable kind of foundations for buildings to resist earth- 

 quake shocks, and pointed out that by far the largest amount of 

 damage done was due to the bad construction of buildings. 

 Hound stones built into the walls of houses were especially 

 objectionable. "With respect to the East Anglian earthquake on 

 the 22nd of April, 1884, Mr. Topley observed that only six of 

 greater violence had been recorded in the British Isles, the 

 last severe one having occurred during the trial of Wycliffe 

 at Westminster Hall in 1-180, which led to the trial being 

 abandoned. One of the effects of the East Anglian earthquake 

 was temporarily to raise the level of the water in wells 400 feet 

 deep to the extent of 7 feet. The water had been .previously 

 sinking, and was now reverting to its former level. 



"Notes on the Furuminifi'ni, with especial reference to the 

 Varieties in the Tests of this class of Animals,'' was the title of 



