io NATURAL HISTORY OF SELBORNE. 



LETTER IV. 



TO THE SAME. 



As in a former letter the freestone 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-like glass, that it is well 

 preserved from injuries of weather, and endures thirty or forty 

 years. When chiseled 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 in 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, f On the ground abroad this firestone 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 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 resists 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 lie deep, 



* There may probably be also in the chalk itself that is burnt for lime a proportion of 

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



t To surbed stone is to set it edgewise, contrary to the posture it had in the quarry, 

 says Dr. Plot, " Oxfordshire," p. 77. But STirbedding 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 me like salts ; saltstone perishes exposed to wet and frost." 

 PLOT'S " Staff.," p. 152. 



