Intelligence and Miscellaneous Articles. 539 



and brownish felspar, in some places — near the Wheal Laity lodes — 

 abounding in tin-ore. 



At about 105 fathoms deep this lode is connected with one of those 

 curious deposits of tin-ore locally called " Carbonas *," as yet un- 

 known in any other part of Cornwall. The union takes place about 

 14 fathoms south of the contact between the Wheal Comfort and the 

 Wheal Laity lodes ; and for 10 fathoms above and 20 fathoms below, 

 as well as for the whole distance between the Wheal Laity lodes and 

 the Carbona, the Wheal Comfort lode when alone is very productive ; 

 but immediately when the Wheal Comfort lode and the " Carbona " 

 separate in descending, — each taking its own downward course, — the 

 lode becomes unproductive, and so also remains as far southward 

 as it has yet been traced. 



At the northern contact of the Wheal Comfort lode and the " Car- 

 bona" there is a rich mass of quartz, felspar, schorl, and tin-ore, at 

 least 15 feet in width for about 5 fathoms in length: both south- 

 ward of and below this spot the lode preserves its usual direction and 

 dip ; but the " Carbona " southward bears about 5° east of the course 

 of the lode, and holds nearly perpendicularly downward. Descend- 

 ing about 5 fathoms it abuts on the granite rock; and is seen no 

 deeper ; except that as it is pursued southward, the irregular granitic 

 bed on which it rests declines at an angle of about 8°. With the 

 exception of a single short string or pipe, no trace whatever of the 

 " Carbona " has rewarded the numerous researches which have been 

 made at greater depths. Nothing can, however, be more irregular 

 than its size and various ramifications. Though the upper edge of 

 the " Carbona" generally continues to touch the lower side {foot- 

 wall) of the lode, in some places the contact is only a few inches, but 

 in others as much as two fathoms and a half wide. Again, in some 

 cases the continuity of the " Carbona " where it joins the lode, is 

 almost entirely cut off by intervening masses of granite ; the union 

 with the main body being still preserved, though merel}'' by "pipes " 

 or " pillars " of lode-\i\ie matter. Many portions of the " Carbona " 

 are as much as five or six fathoms high, others not more than four 

 or five feet ; some parts are two fathoms and a half M'ide, whilst 

 others do not exceed six inches. The largest portions are, however, 

 seldom or never entirely separated from each other by the containing 

 rock, for there is always a sufficient connexion to conduct the 

 miner from one large and rich mass to another. 



The composition of tlie Wheal Comfort lode has been already 

 noticed; but notwithstanding their intimate connexion, that of the 

 " Carbona" is wi>lely different, as its tin-ore occurs chiefly in quartz 

 and schorl, which minerals, either separate or mi.xcd, constitute the 

 far greater portion of this remarkable deposit. 



* Some persons pretend to derive this term from the ancient Cornish 

 lanf^iage, wliilst others sujipose it to Iiave been recently coined by the 

 miners. IJotli the word itself and tlie metalliferous deposit it is nieaiit to 

 designate are, I Itelieve, coiifnied to the St. Ives mining district. — Corn. 

 Geol. Trans, vol. v. p. 21, note. 



