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it to bo so, and in a sense tliis is true, since the chalk underlies about 
1700 square miles out of 2000, the approximate area of the county. 
At the same time, over by far the larger part of the district the 
chalk is covered by the Glacial and other Tertiary beds, often to a 
considerable thickness. Except over a narrow belt of land in 
the west of the county, and in the cliffs of Hunstanton and 
Weyboume, it is only met with along the sides of valleys ; and I 
calculate that the area of bare chalk is less than one sixth of the 
whole superficial extent of this formation in Norfolk. Further, 
how very small a portion of the area which is thus accessible can 
ever become known to us. The average depth of the chalk in 
Norfolk is perhaps between GOO and 700 feet. Our excavations in 
it do not nearly average a twentieth portion of this thickness. 
Perhaps there are in our county, 2000 chalk quarries and pits of 
different sizes. Suppose that during the last few years, in 
which any interest has been taken in geological investigation, 
there have been excavated on the average 5000 cubic yards 
from each pit, we may calculate that the whole amount so brought 
under our notice is less than one hundred-thousandth part of the 
cubical contents of the Norfolk chalk. The proverbial search 
for a needle in a haystack is thus not more hopeless than is 
the likelihood of our stumbling upon any particular fossil, which 
may have been accidentally preserved to us, of the Cretaceous 
period. The chances are more than one hundred-thousand to one 
against us. The case of the chalk is by no means an extreme 
one, because, from its economical value, there are many more 
excavations in it in any given space, than is the case in other 
formations. 
Then again consider that a very small part of the earth’s surface 
has been systematically explored by geologists. The small area of 
the British Isles, and some other portions of the adjacent continent, 
are now becoming pretty well known ; but the geological investigation 
of the vast continents of Asia, Africa, and even of America, has 
been, comparatively speaking, only just commenced. Those of us 
who are confined by the narrow boundaries of our own country, 
may well envy the good fortune of the members of the Geological 
