  The hadronic shift in pionic hydrogen has been redetermined to be
$\epsilon_{1s}=7.086\,\pm\,0.007(stat)\,\pm\,0.006(sys)$\,eV by X-ray
spectroscopy of ground state transitions applying various energy calibration
schemes. The experiment was performed at the high-intensity low-energy pion
beam of the Paul Scherrer Institut by using the cyclotron trap and an
ultimate-resolution Bragg spectrometer with bent crystals.
