1820.] Memoirs of the Literari/ Sociefi/ of Manchester. 199. 



kinds of mineral matter, however hard and brittle they appear to 

 be in hand specimens, will bend less or more when formed into 

 large flat pieces. He explains what are called creeps in old coal 

 mines. This name is given to the slow subsidence of roofs of 

 old coal mines. When the roof sinks rapidly, the process is 

 called a set or seal by the colliers. 



XI. Account of the Black Lead Mine in Burroicda/e, Cumber- 

 land. By Mr. Jonathan Otley. — This mine, according to Mr. 

 Otley, lies in a greywacke mountain near the head of the valley 

 of Borrowdale, which faces the south-east. The black lead d.^es 

 not constitute a vein, but occurs in bellies. Veins of iron ore 

 traverse the mountain, exhibiting traces of black lead, and it is 

 where these veins cross each other that the bellies usually occur. 



When the mine was discovered is not known ; but from a 

 grant made in the beginning of the 17th century, it appears to 

 have been discovered before that time The manor of Borrow- 

 dale is said to have belonged to the Abbey of Furness, and 

 having, at the dissolution of that monastery, in the reign of 

 Henry VIII. fallen to the crown, it was by James I. granted to 

 William Whitmore and Jonas Verdon, including among other 

 things, the Wadholes and Wad, communli/ called Black Cawke,of 

 the i/earli/ Rent or Value of Fifteen Shillings and Fourpence. The 

 said Wilham Whitmore and Jonas Verdon, by a deed bearing 

 date Nov. 28, 1614, sold unto Sir Wilfred Lawson of Isel, and 

 several inhabitants of Borrowdale, all the said manor of Borrow- 

 dale, with the appurtenances of what nature or kind soever i 

 " except the wadholes and wad, commonly called black cavvke, 

 within the conmions of SeatoUor, or elsewhere, within tiie 

 commons and wastes of the said manor." In consequence of this 

 reservation, the black lead mine is held distinct from other 

 royalties of the manor; one half thereof belonging to Henry 

 Banks, Esq. M.P. and the other half subdivided into several 

 shares, one of which belongs to Sir Joseph Banks. 



The mine used formerly to be wrought at irregular intervals, 

 and when the market was supplied, the working was stopped tilla- 

 fresh demand called for a new supply of black lead. But of late 

 years the demand has increased so much that it has been neces- 

 sary to work the mine without intermission. In the year 1/98' 

 an adit was begun on the side of the hill, which at the length of 

 220 yards communicated with the bottom of the old workings. 

 Through this level the water passes off, and the produce ia. 

 brought out to be dressed : and on its mouth a house is built; 

 where the overseer dwells, and the workmen are undressed andfe'; 

 examined as they pass to and from work. From a belly opened' 

 in 1803, 500 casks of black lead of the best quality were pro- 

 cured, weighing about one hundred weight and a quarter each j 

 besides a greater quantity of an inferior sort. Since that time, 

 two of these bellies have been met with, which have produced 

 about 100 casks each. The whole is sent to London, where it 



