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Antiquaries, who published an account of his observations 
ou that occasion in the Philosophical Transactions of the 
Royal Society, whence we gather that these islands abounded 
with the roots of oaks, firs, and birches, still firmly imbedded 
in the soil where they grew, whilst their fallen trunks, 
covered with bark in a very fresh condition, were lying near 
them in the midst of a bed of partially decomposed leaves, 
mixed with decayed rushes, sedges, and other vegetable 
matter, forming a black peaty stratum ; the water was 
observed to deepen on the seaward side of the line of 
islands, so as to form a steep bank, and the channels between 
them were from four to twelve feet deep. From experiments 
made below the surface of the islands, as well as at Sutton, 
Mablethorpe, and other spots on the mainland, it was clearly 
ascertained that the subsoil of both was identical. 
It will now be my endeavour to answer the very natural 
questions that are sure to be put in connection with these 
facts, namely, " When these districts were severally 
submerged by fresh and salt water ?" and " By what 
agency ?" 
Various theories have been advanced for the purpose of 
solving these problems, the principal of which are — 
t. The interference of the Romans with the natural 
drainage. 
2. A change in the coastal line through the action of 
the sea. 
3. The agency of earthquakes causing subsidence of 
the earth. 
Let us shortly consider each of these. There is no 
doubt but that the Romans did raise a continuous sea bank 
along the greater portion of the Lincolnshire coastal line, 
of which considerable remains still exist ; also that they 
deepened the outfalls of rivers and such drains as they 
chose to make or retain, so that in after times, during the 
