Salisbury, England.
1909.
Aug. 19 [August 19, 1909]
(No 2)
  As nearly as I can ascertain by observation and by
questioning the people here the abundance of fine large game
fish in a stretch of river comparable with that of our Charles
where it flows under the bridge at Watertown is due in
part at least to the fact that these fish, through ages of
experience, have become highly sophisticated. No doubt they
could be quickly exterminated by the use of nets, dynamite, "jigging"
etc. but most of them under ordinary conditions, are quite able
to discriminate between artificial fly or baited hook and a morsel
of safer food drifting down with the current. I saw the
fishermen this morning cast ceaselessly for half an hour over
hundreds of large Grayling & dozens of fine Trout yet only
one fish, & that a small one, rose to it & paid the penalty
for his folly. Thus it is probably to protect against
unsportsmanlike methods of fishing, rather than to the
accompanying restriction in the number of fishermen, which enables
the fish to maintain themselves in such extraordinary numbers
in these English rivers even when they flow through the very
heart of crowded cities like Salisbury. The river here, although
beautifully clear, is polluted by more or less drainage. The 
hotel in which we are staying discharges all its sewage directly
into it and I see the iridescent, oily glint of kerosine or
similar oils on its swirling surface while paper of various
kinds is forever floating past.