ANNIVERSARY ADDRESS OF THE PRESIDENT. CXXxUi 



on the nature of the liquidity of lava ; but under what different cir- 

 cumstances does he now advance his opinion ? The theory of craters 

 of elevation was at the time of his first writing in its zenith, as every 

 one seemed to follow the guidance of Von Buch, and it appeared, as is 

 often the case, almost a duty to resist as a lawless intruder every 

 one who differed from that theory. In commenting on the life of 

 Constant Prevost, I have shown how he, after a lapse of many years, 

 had found it necessary to abandon the standard of Yon Buch ; and 

 it may be fairly stated, that the great majority of modern geologists 

 now hold the opinions which ]Mr. Scro})e advocated with so little 

 success more than a quarter of a century ago. All, however, have 

 not abandoned the theory of a crater of elevation ; many are still 

 inchned to ascribe a larger share in the formation of a volcanic 

 mountain to the elevatory process, than would be the result of simple 

 fracture by explosive aeriform eruptions, though they are quite ready 

 to admit that the subsequent eruptions have, by successive accumu- 

 lations of lava and other matters, materially, nay principally con- 

 ducted to the present result. I hope to be able to recur to this sub- 

 ject again ; at present I will only congratulate Mr. Scrope on having 

 so completely outlived the prejudices which were at first so strenuously 

 opposed to his theory of craters as well as to his view of the semi- 

 liquidity of lava. 



Mr. James Gay Sawkins visited, in 1 854, the Island of Tongataboo, 

 one of the Friendly Islands, which had been recently visited by an 

 earthquake, and found that the north-east portion had been tilted 

 down so as to cause an encroachment of the sea for two miles inland, 

 and the western coast had risen some feet. The island is formed of 

 coral, and some parts of it are 116 feet high. This earthquake is 

 said to have led to the appearance of an island to the west of Ton- 

 gataboo, and was followed by an eruption at an island to the 

 north. Mr. Sawkins is of opinion, that upheaval predominates over 

 subsidence in the Pacific, and mentions the occurrence at Tahiti, one 

 of the Society Islands, of alternate layers, upon highly elevated 

 ground, of coral and volcanic lava, so that there must hav& been time 

 for the growth of the coral before and after each eruption previous to 

 the final elevation of the island. 



In respect to papers on minerals, Dr. Rubidge has described the 

 geology of Namaqualand and the bordering countries, and explained 

 the manner in which the copper is found, namely, in fissures of the 

 gneiss, which is disturbed parallel to the strike ; it also occurs in 

 crevices of the rock without any veinstone or gangue. The ores are 

 principally the oxides and silicates ; and the appearances, from the 

 mode of distribution being sometimes deceptive, have led adventurers 

 to imagine that they have found a mountain of copper ore. i\Ir. Dick 

 has given us an analysis of the iron-ore from the Middle Lias of York- 

 shire. The Rev. R. H. Cobbold has announced the existence of a 

 brisrht but not bituminous coal near the citv of E-u in China ; this 

 information coming to us through the Earl of Clarendon as Foreign 

 Minister. The Rev. W. S. Symonds pointed out the analogy between 

 the effects of the great Malvern Bonfire on the syenite forming the 



