100 Mr R. W. Fox on the High Temperature 



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

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

 the " middle lodeT there is a spring or jet of water, dis- 

 charging about 94 gallons a minute, at the temperature of 

 1065° Fahrenheit.! This level is about 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^- feet in 

 a fathom towards the north, and the water flows from its 

 northern or upper nail; whilst from the opposite side, or 

 southern wall of the lode, at the distance of only 3|^ feet, 

 there is another spring, discharging 30 gallons of water in a 

 minute, at the temperature of 97f ° Fahr. The air near both 

 these springs was found to be at 104|° Fahr. : and " ^^7W 

 is the only rock which has been seen within 30 fathoms of 

 them. Granite occurs at a considerable distance westward 

 of the place ; and two " elvan courses'' traverse the mine in 

 nearly the same east and west direction as the lode. 



I have found that J of a pint of the water from the warmer 

 spring contained 15 grains of saline matter, consisting of 

 muriate of lime and common salt, in about equal proportions, 

 with a trace of sulphuric acid, probably combined with lime. 

 In the same quantity of the cooler water, only lOi^ grains of 

 muriate of lime and common salt were found, the latter in 

 less proportion than the former ; and in this water also there 

 was a slight trace of sulphuric acid. In both instances, the 

 water was clear, saline to the taste, and without any metallic 

 salt. 



It may, I think, be inferred from the saline contents of 

 these springs, that they have a common origin or source ; 

 whilst their high temperatures indicate their having come 

 from a considerable depth, and the quantity of water they 

 discharge, that the lode, or rocks beneath, must be very per- 



* This mine (for it is one concern) continues to produce abundance of cop- 

 per ore. It is situated in the parish of Gwennap, about 8 miles to the north- 

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



t 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 bo 

 deducted from the results, making them lOG-OS", 975°, and 104 , respectively. 



