Downstream

A porpoise? I stop reading
again, picturing Derham
midway across the estuary
riding for a moment on the
back of a harbour porpoise.
Then, on 10 June, he
managed the crossing of
thirteen miles in five hours
and modestly explains, ‘I may
mention that this was the first
and only time that the
Thames Estuary had been
conquered.’ He doesn’t
describe his route; one press