18 THE ESSEX NATURALIST.
trap myself, but I now know that, given an appropriate chemical,
or bio-chemical, agency, such patinations may be surprisingly
rapid. I cannot here detail all the evidences, and it must
suffice to say that on many sea beaches—the Chesil bank, for
example—one can observe the fluctuating balance between the
wearing off of the older patinations by the friction caused by the
waves, and the re-patination of the fresh surfaces. On the
whole, the re-patination wins, and the general effect remains
permanently ochreous.
Upon the Cromer coast itself one can sometimes find a deep
ochreous patination upon flints that still remain rooted in their
original Chalk bed, and were completely embedded in it not so
very many years ago; while on the "spread" the facets, or
"scars," left upon the flint boulders by the removal of the
"Cromerian" flakes exhibit every stage of patination from the
perfectly fresh and new through blue and whitish-blue to white,
and thence from yellowish over white to the deepest ochreous,
which must, on the average, be the oldest. Most of the boulders
carry flaking of several different dates, and so also do the flakes
themselves.
Conclusion.—In the course of this address I have passed
in review certain of the traps and difficulties of interpretation
that in the course of my experience I have found to be particularly
dangerous or misleading. We can never be too keenly on our
guard against wishful thinking, hasty generalisations, or trusting
to abstract reasoning, in place of getting into a direct association
with realities by observation.
Owing to the difficulties of the time, the foregoing pages have
suffered much condensation, so I hope the reader will do his
best to fill in the gaps in the incomplete descriptions.
I cannot conclude without expressing my appreciation of
the honour you have done me in electing me as your President
for a second term of office after the lapse of a quarter of a
century—an experience that does not fall to the lot of many.
REFERENCES.
Submerged Prehistoric Surface. Essex Nat., vol. xvi, 1909, p. 46 ; xxiv,
p. 1 ; Journ. R. Anthrop. Inst., vol. xlii., 1912, p. 91 ; Proc. Prehist.
Soc, n.s., vol. ii, 1936, p.178.
Correlation ; Lea Valley Deposits. Quart. Journ. Geol. Soc, vol. lxviii
1912, p. 213. Proc Prehist. Soc, n.s., vol. iv, 1938, p. 328.