148 Dr. Correa de Serra on a submarine Forest , 
of the same nature is found under ground, in that part of the 
country, at the depth of sixteen feet; consequently, very nearly 
on the same level with that which constitutes the islets. The 
disposition of the strata was found to be as follows : 
Clay, - - - - 1 6 feet. 
Moor, similar to that of the islets, from 3 to 4 ditto. 
Soft moor, like the scowerings of a ditch 
bottom, mixed with shells and silt, - 20 ditto. 
Marly clay, 1 foot. 
Chalk rock, - - from 1 to 2 feet. 
Clay, - - - 31 yards. 
Gravel and water ; the water has a chalybeate taste. 
In order to ascertain the course of this subterraneous stratum 
of decayed vegetables, Sir Joseph Banks directed a boring to 
be made, in the fields belonging to the Royal Society, in the 
parish of Mablethorpe. Moor, of a similar nature to that of 
Searby’s well, and of the islets, was found, very nearly on the 
same level, about four feet thick, and under it a soft clay. 
The whole appearance of the rotten vegetables we observed, 
perfectly resembles, according to the remark of Sir Joseph 
Banks, the moor which, in Blankeney fen, and in other parts 
of the East fen in Lincolnshire, is thrown up in the making 
of banks ; barks, like those of the birch tree, being there also 
abundantly found. This moor extends over all the Lincoln- 
shire fens, and has been traced as far as Peterborough, more 
than sixty miles to the south of Sutton. On the north side, 
the moory islets, according to the fishermen, extend as far as 
Grimsby, situated on the south side of the mouth of the Humber; 
and it is a remarkable circumstance, that in the large tracts of 
low lands which lie on the south banks of that river, a little 
