OF SELBORNE 7 



LETTER IV. 



TO THE SAME. 



As in a former letter th.& freestone i of this place has been only- 

 mentioned incidentally, I shall here become more particular. 



This stone is in great request for hearth-stones, and the beds 

 of ovens : and in lining of lime-kilns it turns to good account ; for 

 the workmen use sandy loam instead of mortar ; the sand of 

 which fluxes,^ and runs by the intense heat, and so cases over the 

 whole face of the kiln with a strong vitrified coat Uke glass, that 

 it is well preserved from injuries of weather, and endures thirty 

 or forty years. When chiselled smooth, it makes elegant fronts 

 for houses, equal in colour and grain to the Bath stone ; and 

 superior in one respect, that, when seasoned, it does not scale. 

 Decent chimney-pieces are worked from it of much closer and 

 finer grain than Portland ; and rooms are floored with it ; but it 

 proves rather too soft for this purpose. It is a freestone, cutting 

 m all directions ; yet has something of a grain parallel with the 

 horizon, and therefore should not be surbedded, but laid in the 

 same position that it grows in the quarry.^ On the ground abroad 

 this fire-stone will not succeed for pavements, because, probably 

 some degree of saltness prevailing within it, the rain tears the 

 slabs to pieces.* Though this stone is too hard to be acted on 

 by vinegar ; yet both the white part, and even the hltie 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 dur- 



1 [The sandy beds of the upper greensand.] 



2 There may probably be also in the chalk itself that is burnt for lime a pro- 

 portion of sand : for few chalks are so pure as to have none. 



* To surbed stone is to set it edgewise, contrary to the 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. 



* "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. 



'[Calcareous bands of the upper greensand.] 



