  A sample of 477 solar-type binaries within 67pc with projected separations
larger than 50AU is studied by a new statistical method. Speed and direction of
the relative motion are determined from the short observed arcs or known
orbits, and their joint distribution is compared to the numerical simulations.
By inverting the observed distribution with the help of simulations, we find
that average eccentricity of wide binaries is 0.59+-0.02 and the eccentricity
distribution can be modeled as f(e) ~= 1.2 e + 0.4. However, wide binaries
containing inner subsystems, i.e. triple or higher-order multiples, have
significantly smaller eccentricities with the average e = 0.52+-0.05 and the
peak at e ~ 0.5. We find that the catalog of visual orbits is strongly biased
against large eccentricities. A marginal evidence of eccentricity increasing
with separation (or period) is found for this sample. Comparison with
spectroscopic binaries proves the reality of the controversial
period-eccentricity relation. The average eccentricity does increase with
binary period, being 0.39 for periods from 10^2 to 10^3 days and 0.59 for the
binaries studied here (10^5 to 10^6 days).
