OF SELBORNE 17 



horizon, and therefore should not be surbedded, but laid 

 in the same position as it grows in the quarry.* On the 

 ground abroad this firestone will not succeed for pave- 

 ments, because, probably, some degree of saltness 

 prevailing within it, the rain tears the slabs to pieces.j 

 Though this stone is too hard to be acted on by 

 vinegar ; yet both the white part, and even the blue rag, 

 ferments strongly in mineral acids. Though the white 

 stone will not bear wet, yet in every quarry at intervals 

 there are thin strata of blue rag, which resist rain and 

 frost ; and are excellent for pitching of stables, paths and 

 courts, and for building of dry walls against banks ; a 

 valuable species of fencing, much in use in this village, 

 and for mending of roads. This rag is rugged and 

 stubborn, and will not hew to a smooth face ; but is very 

 durable : yet, as these strata are shallow and he deep, 

 large quantities cannot be procured but at considerable 

 expense. Among the blue rags turn up some blocks 

 tinged with a stain of yellow or rust colour, which seem 

 to be nearly as lasting as the blue ; and every now and 

 then balls of a friable substance, like rust of iron, called 

 rust balls. 



In Wolmer-forest I see but one sort of stone, called by 

 the workmen sand, or forest-stone. This is generally of 

 the colour of rusty iron, and might probably be worked as 

 iron ore ; is very hard and heavy, and of a firm, compact 

 texture, and composed of a small roundish crystalline 

 grit, cemented together by a brown, terrene, ferruginous 

 matter ; will not cut without difficulty, nor easily strike 



* To surbed stone is to set it edgewise, contrary to tlie posture it 

 had in the quarry, says Dr. Plot, Oxfordsh., p. 77. But surbedding 

 does not succeed in our dry walls ; neither do we use it so in ovens, 

 though he says it is best for Teynton stone. 



t " Firestone is full of salts, and has no sulphur : must be close 

 grained, and have no interstices. Nothing supports fire like salts ; 

 saltstone perishes exposed to wet and frost." Plot's Staff., p. 152. 



