German Ocean, or North Sea. 4T 
miles, while the aggregate superficial contents of the sand-banks 
alone amount to no less than 275443 square miles, or in- 
clude an area of about 5| of the whole surface of the North 
Sea.' 
But to render these dimensions a little more familiar by compa- 
rison, we may notice, that the Island of Great Britain contains 
about 77,244 square miles, being not quite one-half of the area 
of the North Sea ; so that the area of the Sand-banks bears a 
proportion equal to about one-third of the whole terra firma of 
England and Scotland ; and they are, therefore, perhaps, far more 
considerable in their extent than has been generally imagined. 
In speaking of the dimensions of sand-banks situate in the 
middle of the ocean, we are aware that great allowance must be 
made in forming a proper estimate of their extent, especially 
in speaking of their cubical contents. From a vast number of 
observations and comparisons relative to this subject, I have, 
however, been enabled to determine, that the average height of 
these banks measures about 78 feet, from a mean taken of the 
whole. In ascertaining their height above the surrounding 
bottom, the measurement has been taken from the general 
depth around each respectively. Now, upon taking the ag- 
gregate cubical contents of the whole of these immense collec- 
tions of debris, supposing the mass to be uniformly the same 
throughout, it is found to amount to no less a quantity than 
2,241,248,563,110 of cubic yards, being equal to about 14 feet 
of the depth of the whole German Ocean, or to a portion of the 
firm ground of Great Britain, on a level with the sea, taken 28 
feet in perpendicular height or depth, supposing the surface to 
be a level plane. 
These calculations at least tend to shew that an immense 
body of water must be displaced, in consequence of these banks 
occupying so very considerable a proportion of the bed of the 
North Sea, the unavoidable effect of which must give a direct 
tendency to the tidal waters, and the flux produced by storms 
in the Atlantic, to overflow the bed of the German Ocean, in 
the same manner as if stones or other matter were thrown into 
a vessel already nearly brimful of water. This may further be 
illustrated by considering the actual state of any of the great 
inland lakes, as those of Geneva, Lochness, Lochlomond, &c. 
