  Deep-inelastic ep scattering data, taken with the H1 detector at HERA, are
used to study event shape variables over a large range of "relevant energy" Q
between 7 GeV and 100 GeV. Previously published analysis on thrust, jet
broadening, jet mass and C parameter are substantially refined and updated;
differential two-jet rates treated as event shapes are presented for the first
time.
  The Q dependence of the mean values is fit to second order calculations of
perturbative QCD applying power law corrections proportional to 1/Q^p to
account for hadronization effects. The concept of these power corrections is
tested by a systematic investigation in terms of a non-perturbative parameter
\bar{alpha}_{p-1} and the strong coupling constant.
