Intelligence and Miscellaneous Articles. 541 



for some distance unproductive, whilst the Wheal Laity south lode is 

 rich in tin- ore on both sides of the Cross-course, and for some fathoms 

 both above and below the gallery (level), the Cross-course consists 

 of a rich vein of tin-ore for the whole interval (five fathoms) between 

 the eastern portions of the two lodes, as well as of a fine mass of the 

 same ore at its contact with the western part of the Wheal Laity 

 south lode. 



(3.) At 130 fathoms deep the Wheal Laity south lode is also 

 heaved, but in an opposite direction, by a vein of granitic clay (the 

 Flucan). This flucan is not prolonged to either of the other Wheal 

 Laity veins ; nor, indeed, does it reach any other gallery {level) even 

 on the same lode. 



(4.) The Wheal Comfort lode and the Cross-course have the 

 same direction, but, as already observed, opi^osite inclinations ; and 

 are so situated that they come into contact on the line of their dips 

 at about 130 fathoms deep. From the point where they first touch 

 each other they descend perpendicularly side by side for about three 

 fathoms, each keeping the same relative position it had previously 

 when separate (viz. the Cross-course on the west, and the Wheal 

 Comfort lode on the east). At length, however, the lode cuts through 

 the Cross-course. After this intersection, though they have changed 

 sides, and their relative position is reversed, they still proceed 

 together, but now take the line of the lode's previous underlie for 

 several fathoms. When they separate, the lode preserves its dip ; 

 but the Cross-course, though it resumes the previous direction of 

 its inclination, dips eastward far more rapidly than before. It may, 

 indeed, be generally observed, that a vein which has been displaced 

 by another, whether the intersection be horizontal or vertical, makes 

 (if I may be permitted the expression) an eflfort to resume its original 

 course. 



(5.) The Wheal Lait}'^ lodes are intersected as well by the Wheal 

 Comfort lode and the Cross-course during their union, as by each of 

 them when separate ; the union, however, has little or no influence 

 on the extent of the heave. 



Many details of local, and some, indeed, of general interest, 

 scarcely need be mentioned, as this i)aper may be deemed su])ple- 

 mentary to my remarks on the St. Ives District* ; and especially 

 to a description of a similar interesting formation at the St. Ives 

 Consolidated Mines, which has already appeared in the Transactions 

 of the Royal Geological Society of Cornwall f. 



A small stream issues from the Wheal Laity north lode at 150 

 fathoms deep, having a temperature of 71° ; whilst that of the water 

 discharged by the pump at the adit (45 fathoms from the surface) 

 is only 63'' 6' J. 



* Corn. Geol. Trans, vol. v. p. Hi. t Ibid. ]). L'l. 



J Observations on the temjjcraturc of other parts of the Providence 

 Mines are recorded in the Society's Transactions, vol. v. p. liW. 



