usually very small and soft: but in Clay's Pond, a little farther on, at
the end of the pit, where the soil is dug out for manure, I have
occasionally observed them of large dimensions, perhaps fourteen
or sixteen inches in diameter. But as these did not consist of firm
stone, but were formed of a kind of terra lapidosa, or hardened
clay, as soon as they were exposed to the rains and frost they
mouldered away. These seemed as if they were a very recent
production. In the chalk-pit, at the north-west end of the Hanger,
large nautili are sometimes observed.

In the very thickest strata of our freestone, and at considerable
depths, well-diggers often find large scallops or pectines, having
both shells deeply striated, and ridged and furrowed alternately.
They are highly impregnated with, if not wholly composed of, the
stone of the quarry.



Letter IV
To Thomas Pennant, Esquire

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