Below the City shield is a coat of arms which bears the motto "Strike Dakin strike".
Asking Google about the motto, we find
Kelly's Directory for Derbyshire, 1891 which tells us that in St Peter's Church Fairfield there is a mural tablet to William Dakin, a merchant of London (1848) with the singular motto of that family, "Strike, Dakin, strike; the Devil's in the Hemp".
(Here the punctuation gives an indication of who is supposed to be striking whom!)
The church's website does not mention the tablet but tells of two other Dakins in the graveyard.
In fact the rest was probably presented to the church by
Thomas Dakin (1808-1889) who was a Lord Mayor.
This page (cached copy) on Deakins of Australia and England gives a good explanation of what the motto means.
Another Google hit comes from an unlikely source: small town Minnesota, in
this article (cached copy) from the
Kanabec County Times about someone being busted with $1000 dollars worth of pot [=
Cannabis = hemp]. It definitely must be small town because the story has generated forty eight comments! One of these (search text for Dakin) is from someone who still has the family motto word perfect after seven generations.