PETRIFIED SHELLS.-As you ride from Cricklad to Highworth, Wiltsh., you find frequently roundish stones, as big,, or bigger than one's head, which (I thinke) they call braine stones, for on the outside they resemble the ventricles of the braine; they are petrified sea mushromes. [Fossil Madrepores ?-J. B.]
The free-stone of Haselbury [near Box] hath, amongst severall other shells, perfect petrified scalop-shells. The rough stone about Chippenham (especially at Cockleborough) is full of petrified cockles. But all about the countrey between that and Tedbury, and about Malmesbury hundred, the rough stones are full of small shells like little cockles, about the bigness of a halfpenny.
At Dinton, on the hills on both sides, are perfect petrified shells in great abundance, something like cockles, but neither striated, nor invecked, nor any counter-shell to meet, but plaine and with a long neck of a reddish gray colour, the inside part petrified sand; of which sort I gave a quantity to the R. Society about twenty yeares since; the species whereof Mr. Hooke says is now lost.
On Bannes-downe, above Ben-Eston near Bathe, [Banner-downe, near Bath- Easton.- J. B.] where a battle of king Arthur was fought, are great stones scattered in the same manner as they are on Durnham-downe, about Bristow, which was assuredly the work of an earthquake, when these great cracks and vallies were made.
The like dispersion of great stones is upon the hills by Chedar rocks, as all about Charter House, [Somersetshire,] and the like at the forest at Fountain-Bleau, in France; and so in severall parts of England, and yet visible the remarques of earthquakes and volcanoes; but in time the husbandmen will cleare their ground of them, as at Durnham-downe they are exceedingly diminished since my remembrance, by making lime of them.
The great inequality of the surface of the earth was rendred so by earthquakes: which when taking fire, they ran in traines severall miles according to their cavernes; so for instance at Yatton Keynell, Wilts, a crack beginnes which runnes to Longdeanes, in the parish, and so to Slaughtonford, where are high steep cliffs of freestone, and opposite to it at Colern the like cliffs; thence to Bathe, where on the south side appeare Claverdon, on the north, Lansdon cliffs, both downes of the same piece; and it may be at the same tune the crack was thus made at St. Vincent's rocks near Bristow, as likewise Chedar rocks, like a street. From Castle Combe runnes a valley or crack to Ford, where it shootes into that that runnes from Yatton to Bathe. ___________________________________
Edmund Waller, Esq., the poet, made a quaere, I remember, at the Royal
Society, about 1666, whether Salisbury plaines were always plaines ?
In Jamaica, and in other plantations of America, e. g. in Virginia, the natives did burn down great woods, to cultivate the soil with maiz and potato-rootes, which plaines were there made by firing the woods to sowe corne. They doe call these plaines Savannas. Who knowes but Salisbury plaines, &c. might be made long time ago, after this manner, and for the same reason ?
I have oftentimes wished for a mappe of England coloured according to the colours of the earth; with markes of the fossiles and minerals. [Geological maps, indicating, by different colours, the formations of various localities, are now familiar to the scientific student. The idea of such a map seems to have been first suggested by Dr. Martin Lister, in a paper on "New Maps of Countries, with Tables of Sands, Clays, &c." printed in the Philosophical Transactions, in 1683. The Board of Agriculture published a few maps in 1794, containing delineations of soils, &c.; and in 1815 Mr. William Smith produced the first map of the strata of England and Wales. Since then G. B. Greenough, Esq. has published a similar map, but greatly improved; and numerous others, representing different countries and districts, have subsequently appeared. - J. B.] ___________________________________
The great snailes* on the downes at Albery in Surrey (twice as big as ours) were brought from Italy by ..-.., Earle Marshal about 1638. ___________________________________