OFSTONES. 6 5 



out; the largeft not above twelve inches long, and fix inches 

 broad. Mechanics are very fond of them. 



On the edge of the brook at Sivinburn-catile, above the mill, is 

 a plated rock, of a light greyifh-blue colour, and exceeding fine 

 texture, from which I have had whetftones that give a very good 

 edge to penknives. They are alfo fcarce. Small mafles arc 

 fometimes found lying on the pavement of the brook below the 

 mill, turned out by floods ; the longed not above fourteen inches, 

 and five or fix inches broad. There is a variety of it of a fofcer 

 texture ; very much ufed in that neighbourhood within doors 

 for giving a white flone-colour to chimney-pieces and hearths. 



In the grounds of a farm, called Black-Carts, near a gate lead- 

 ing to Neivbrough, from the military road, is a laminated flcne 

 of a light grey, and alfo of a dark blue colour, of great ufe to 

 fhoemakers in giving an edge to their knives, for cutting leather. 

 It is alfo ufed in writing-fchools for pencils, for the Irt/b (late, 

 drawing a white line freely. That at Stvinburn is frequently put 

 to the fame ufe. 



Quarry-marble, or marble found in (Irata, is not uncommon. 

 A fine lort was lately difcovered on the eftate of Sir John Lambert 

 Middleton, of Belfay, Bart, by a farm, called the Park-Ho-'ife. It is 

 of a grey colour, with ftreaks of black, thick fet with that large, 

 fcarce, and beautiful coralloid, the Alcynohim of Mr. Edward 

 Lhivyd, faid by Sir Hans Sloane to be a native of the American feas, 

 (a), of a whitim-brown colour, lying in all directions (b). It 

 is of a fine texture, and great brightnefs, rightly polifhed. It 

 rifes in large blocks, ten or eleven feet long, five or fix feet 



(a) Ph. Tr. No. 257. 



(b) Marmor coralliticum, durius, cinereo nigrefcens. Hill. Hift. Foil". 472. No. i. 



VOL. I. K broad, 



