It is this last idea, often upsetting to
the collective American ego, that con-
tains a central cultural meaning of pre-
stressing which springs from the fact
that the structures of a locale charac-
terize the local culture perhaps better
than any other set of artifacts.
To focus on that fact and to narrow
my scope, I shall consider here only
bridges (with one exception), even
though we are all aware that prestress-
ing has broad application to all kinds
of buildings and other structures. Still,
the idea of prestressing arose out of
bridge design, and its most impressive
forms, from a purely engineering
viewpoint, appear in bridges.