  The muon telescopes of the Extreme Energy Events (EEE) Project are made of
three Multigap Resistive Plate Chambers (MRPC). The EEE array is composed, so
far, of 59 telescopes and is organized in clusters and single telescope
stations distributed all over the Italian territory. They are installed in High
Schools with the aim to join research and teaching activities, by involving
researchers, teachers and students in the construction, maintenance, data
taking and data analysis. The unconventional working sites, mainly school
buildings with non-controlled environmental parameters and heterogeneous
maintenance conditions, are a unique test field for checking the robustness,
the low-ageing features and the long-lasting performance of the MRPC technology
for particle tracking and timing purposes. The measurements performed with the
EEE array require excellent performance in terms of time and spatial
resolution, efficiency, tracking capability and stability. The data from two
recent coordinated data taking periods, named Run 2 and Run 3, have been used
to measure these quantities and the results are described, together with a
comparison with expectations and with the results from a beam test performed in
2006 at CERN.
