MATHEMATICIAN, ASTRONOMER, ENGINEER

Life
Meton was the son of Pausanias, and a native of Athens (like Demosthenes, he was from the Deme of Leuconoe, between present-day Stavros and Paiania). He studied engineering and geometry (reference in Phrynichus and Aristophanes) and astronomy (reference in Theophrastus) with Phaeinus of Athens, who made astronomical observations from his observatory on Lycabettus Hill (432 BC). He is cited by Theophrastus in his "On signs of weather", and also by Vitruvius. One of the craters on the moon has been named "Meton" in his honour. None of his written work has survived.


Work
Meton is known for the 19-year "Metonic cycle", which he introduced into the ancient Athenian luni-solar calendar as a fixed system for recording astronomical observations. He calculated that 19 solar years (6940 days) corresponded to 235 "lunations" (synodic or lunar months), of which 110 were deficient (29 days) and 125 complete (30 days). Nine of these months were intercalary, that is, they were added to certain years of the cycle as a 13th month. This period of 19 years was known as a Metonic or lunar cycle. The Metonic cycle is still used to determine the date of Easter, since every 19 years the phases of the moon recur on the same days of the solar year.

Meton constructed a solar clock (433 BC) that he set up near the Pnyx. He designed and built a number of waterworks, including the Colonos aqueduct mentioned by Phrynichus (Menotropus): "I know that the one who collects the springwaters... may have built a fountain in Colonos". He was assisted in his work by his pupil Euctemon, and together they made observations of the position of the sun at the equinox. As a geometer he worked on the problem of the squaring of the circle. This is alluded to by Aristophanes in his "Birds".

- Parapegma: Calendar erected in the centre of Athens (432 BC). This was a large marble table on which were placed smaller tablets of bronze. It showed the months, the years, the festivals, and the risings and settings of the sun and stars.