132 OF ORES AND COALS. 



and worked by the owner, Mr. Henry Penreth, merchant in New- 

 cafile, for fome time, but difcontinued after a few trials. 



There was lately a boring for lead-ore at Overton, near Simon- 

 burn on the eftate of Sir Ralph Milbank, of Hannaby, Bart, but it 

 was found not to anfwer the expence of working. I have two 

 ipecimens of the ore, one of them a fmall nodule, very ponder- 

 ous, of that kind which our miners call, Fl.oat-Orc. 



Northumberland-\3.d.-ore. yields a moderate mare of filver, is foft, 

 duclile, and fufes kindly in the fire. The ingenious Dr. Wood- 

 ward informs us, that there is a lead-ore got at 



brought to Neivcajlle to be worked, which yields betwixt twenty 

 or thirty ounces of filver per ton, which is the richeft he knew of 

 in England (f). The great Mr. Boyle acquaints us he has known 

 it obferved, that lead-ore, which is poor in its own metal, affords 

 more filver than others ; and affures us, that he had fome lead- 

 ore, which on trial yielded three parts in four of good lead, and 

 yet in the cuppel fcarce yielded an atom of filver (g). 



From the lead-mines at Allen-Heads and Falloivfield, I have been 

 furniflied with fome lead-ores, curious and beautiful, deferving 

 notice. 



1. TefiTellated lead-ore, ponderous and rich, the tcffelx moflly 

 of a parallelepiped figure, and of a fine natural polifh. 



2. Globofe, multangular lead-ore, with plain fides, in the 

 manner of cryftalline fpar, but not regular ; called by the 



(f) Cat. of Foffils, Part 2cl. p. 84. ( g ) Ph. Tr. No. 19. p. 339. 



miners^ 



