Nature^ Longevity^ and Size of Trees, 2B 



which, by their interlacement form the woody layer, another 

 supply is provided in the succulent cambium into which those 

 fibres pass, and along which they descend to the soil. From 

 this, of course, is ultimately derived the materials, or a part of 

 the materials, necessary for the growth of the young plants 

 emanating from the buds. 



Some Bemarks on the High Temperature in the United Mines 

 in Cornwall.* By ROBERT Weee Fox. Communicated by 

 the Author. 



The temperature of some of the deeper parts of the United 

 Minest has long been observed to be remarkably high ; and 

 it has greatly increased with the increasing depth of the ex- 

 cavations. 



Captain Youren, one of the agents of the mine, informs 

 me, that near the eastern extremity of the deepest level, on 

 the " middle lode^'' there is a spring or jet of water, dis- 

 charging about 94 gallons a minute, at the temperature of 

 106J°| Fahr. This level is 250 fathoms below the surface, 

 and about 200 fathoms under the level of the sea. The 

 ** lode" has an underlie or dip of about 2 J feet in a fathom 

 towards the north, and the water flows from its northern or 

 upper wall; whilst, from the opposite side, or southern wall 

 of the lode, at the distance of only Z\ feet, there is another 

 spring, discharging 30 gallons of water in a minute, at the 

 temperature of 97|° Fahrenheit. The air near both these 

 springs was found to be at 104j° Fahrenheit'; and " killas'' is 

 the only rock which has been seen within 30 fathoms of 

 them. Granite occurs at a considerable distance westward 



* Read 3d September 1846, before the Royal Cornwall Polytechnic Society. 



t This mine (for it is one concern) continues to produce abundance of copper 

 ore. It is situated in the parish of Gwennap, about eight miles \.o the north- 

 ward, or almost NN W. of Falmouth, and is several miles from the sea. 



% The thermometer employed has been carefully compared with a standard 

 one, and found to be ^ of a degree too high, so that this small amount must be 

 deducted from the results, making them 106•08^ 97-5°, and 104°, respectively. 



