ACCURACY OF EARLY ESTIMATES OF LUNAR ECLIPSE MAGNITUDES

Estimates of lunar eclipse magnitudes made with the unaided eye by ast ronomers in antiquity are analysed, with a view to determining the acc uracy with which the eye can estimate such a quantity. These observati ons are recorded in Babylonian, Chinese, Arabic and European history. It is shown that the discrepancies between observation and computation follow a remarkably skew distribution. In general, the magnitudes of small eclipses (less than half of the disk covered) are over-estimated , while with large eclipses the reverse is true.