  The energy spectrum of the cosmic radiation in the range
10$^{19}$-2.4$\times$10$^{21}$ eV has been recently predicted showing a rich
and distinctive staircase profile. In order to check the prediction, the
spectra measured by running and past experiments above 10$^{19}$ eV are
examined. The computed spectrum compares more favourably with the Telescope
Array, HiRes I and Yakutsk data rather than with the Auger data in the range
(1-20)$\times$10$^{19}$ eV. Previous flux measurements by Haverah Park, {\sc
sugar}, {\sc agasa} and Fly's Eye experiments are above the predicted spectrum
in the limited band (1-30)$\times$10$^{19}$ eV. The flux measured by the Auger
Group in the band (8-18)$\times$10$^{19}$ eV is below those of all other
experiments and below the prediction.
  The energy scales of the instruments might be at the origin of the flux
mismatch among the experiments. Accordingly, the energy scales of all the
eleven instruments operating above 10$^{20}$ eV are examined and the major
inconsistencies discerned. The paucity of events above 10$^{20}$ eV of the
Auger experiment with respect to all others is by far the major puzzle emerging
from this scrutiny. The Auger instrument recorded only 4 events above 10$^{20}$
eV with an exposure exceeding 42500 km$^{2}$ sr year while the Telescope Array
recorded 13 events with an exposure of 8100 km$^{2}$ sr year. A tentative
solution of this puzzle is ventilated.
