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 as it grows in the
quarry.** 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 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 lie 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.
(* 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.)
(** 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,