422 Proceedings of the British Association 



m the Atlantic near the Line, and midway between Guinea and Brazil ; 

 vessels passing this tract almost always experienced shocks, — the 

 soundings were extremely variable, some being obtained at 400 faihoms, 

 whilst at very snr.all distances the depth was exceedingly great, as if 

 the bottom was formed by a group of volcanic mountains. The con- 

 neclion between earthquake hnes and volcanic lines was very apparent 

 on this map ; but some earthquake regions, like Central Siberia and a 

 tract extending from India to Bohemia, display very little volcanic en- 

 ergy. On a diagram section of the globe, the most distant points at 

 which great earthquakes had been felt were connected by straight lines ; 

 these showed what very large portions of the mass of the earth might 

 have been affected supposing the original impulses to have been cum- 

 municaled at very great depths. Lastly, Mr. Mallet called attention to 

 the great want of bibliographical catalogues in all public libraries, which 

 rendered the search after earthquake literature a work of enormous 

 labor. 



Mr. Hopkins remarked that whilst he placed no faith in such indica- 

 tions as those of earthquakes being more frequent in winter, they were 

 yet very curious; and \\ was not yet known how much might be due to 

 the influence of apparently trivial causes. With regard to the con- 



dition of the interior of the globe, and looking at the earthquake map, 

 he was still disposed to lean towards the hypothesis of the existence of 

 internal lakes of fluid, more or less disconnected, in preference to a 

 fluid central nucleus; earthquake shocks would be propagated to great 

 distances beyond the boundaries of the agitated fluid. 



r 



5. Report on the Physical and Economical Effects of the Destruction 

 of Tropical Forests in British India; by Dr. H. Cleghorn. 



Viewing the question in its physical relations, the author drew atten* 

 tion to the climatic influences of the denudation of the surface of the 

 country ; he adverted to the known phenomena of decrease vC springs, 

 and the consequent diminution of river supplies, as results of the entire 

 removal of the woods which are collected on the highlands, where such 

 supplies usually originate ; — and while distinctly admitting that wherever 

 the wants of an advancing population require the clearance of forest 

 lands, whether for food or the protection of health, such clearance is 

 to be encouraged, he at the same time insisted strongly on the proprie- 

 ty of exercising a careful vigilance, under well defined regulations, in 

 all cases in which the above mentioned causes are not in operation. 

 In considering the economic relations of the question, Dr. Cleghorn 

 availed himself largely of the labors of various distinguished and in- 

 telligent observers to illustrate the effects of the existing imperfect sys- 

 tem of protection and superintendence. He recorded evidence as to 

 the slate of the forests in Malabar, Canara, Mysore, Travancore, the 

 Tenasserim provinces, the Indian Archipelago, and the wooded tracts 

 which skirt the base of the Himalayas. From this evidence, it ap- 

 pears that neither the government nor the community derive from the 

 forests all those advantages which they are calculated to afford. There 

 are numerous products of which the value is known and appreciated,— 

 but which are collected in ways so rude and wasteful, that it is doubt- 

 ful whether more of them are not lost in the process than are brought 



