  A re-investigation of the parapegma of Euktemon (5th century BC, Athens),
based on the assumption that some star observations may in fact have been
calculated rather than directly observed. The calculation follows Pliny,
Natural History 18.218, where he states that the sun should be at least
three-quarters of an hour below the horizon. So 'observations' were based on
time, rather than on star magnitude.
