7 6 NATURAL HISTORY 
that where fand lies either in a jlratum on the higheft hills, or in 
cliffs far above full-fea mark, with marine bodies, either mixed in and 
throughout, or depofited in a diftmct feparate layer. Of both thefe 
phenomena I fhall defcribe two remarkable inftances, and then 
endeavour to inveftigate the caufe. 
In St Juft In a cree hj called Por’nanvon, in the pariih of St. Juft, Pen- 
with, near Cape Cornwall, in the Northern part of the cliff, 
( Plate XIX. Fig. IV.) inferted under the clay and rubble, are ranged 
horizontally many rowes of large and fmall roundifti pebbles of the 
granite kind (from B. E. to C.) : the covering of this pebbly Jlratum 
is fifty feet deep from A to B on the North end, but only twenty 
from D to E on the South, confifting of a rough yellow clay, 
charged here and there with large and fmall ftones, all with their 
angles on, but no folid Jlratum of rock above the pebbles. It is a 
very remarkable ftru&ure which this cliff prefents us with, and 
highly deferves the attention of the curious in all its parts. Firft, 
the large pebbles, from one foot and a half diameter, to fix inches, 
which are inferted now in the cliff, are of the fame fize and texture 
as thofe ftrewed on the ftrand below, which, being tolled to 
and fro by the force of the tide, owe their roundnefs moft pro- 
bably to their circumvolutions. Secondly, I muft obferve, that, 
upon examining the interftices of this pebbly Jlratum , I found many 
fmall black killas and flatty ftones, all with their angles fmoothed 
off, and between them fand of different kinds at different levels. 
That fand which was undermoft, confifted of tranfparent granules, 
fpeckled with black, tailed fait, left a little colour of earth betwixt 
the fingers, but fo little that it fcarce coloured the water in which 
I walhed it : the fand, higher up in this Jlratum , was lefs pure, 
approaching to the colour of reddilh clay ; but higher up, the fand 
was of a ftronger yellow, equally fait, left fome fine clay on the 
fingers, and in the microfcope had many opaque and angular little 
yellow maffes among its particles, as being more affe&ed with the 
clay and gravel which lay over it, than what was deeper. In fhort, 
the fand of thefe interftices, though now fifteen feet higher at a 
medium than full-fea mark, had all the evidence which could be ex- 
pected, that it had come from the fea, and was afterwards covered’ 
by a load of rubbifh, from twenty to fifty feet deep. 
in St. Agnes. Again : One of the higheft hills adjoining to the fea fhore, which 
we have in Cornwall, is St. Agnes Beacon, on the fide of which 
mountain, computed at leaft 480 feet above the level of the fea, 
the Jlrata , upon digging, appear in the following order : The ve- 
getable foil and common rubble under it, five feet deep ; a fine 
fort 
