  In order to construct examples for interacting quantum field theory models,
the methods of euclidean field theory turned out to be powerful tools since
they make use of the techniques of classical statistical mechanics.
  Starting from an appropriate set of euclidean n-point functions (Schwinger
distributions), a Wightman theory can be reconstructed by an application of the
famous Osterwalder-Schrader reconstruction theorem. This procedure (Wick
rotation), which relates classical statistical mechanics and quantum field
theory, is, however, somewhat subtle. It relies on the analytic properties of
the euclidean n-point functions.
  We shall present here a C*-algebraic version of the Osterwalder-Scharader
reconstruction theorem. We shall see that, via our reconstruction scheme, a
Haag-Kastler net of bounded operators can directly be reconstructed.
  Our considerations also include objects, like Wilson loop variables, which
are not point-like localized objects like distributions. This point of view may
also be helpful for constructing gauge theories.
