[HM] On the 135-moon eclipse cycle in the Canary Islands

Jose Barrios Garcia (jbarrios@ull.es)
Tue, 5 Jan 1999 14:40:11 -0000

Dear Moshe' Machover

Although it is true that the 235-moon cycle (also known as metonic cycle)
can be used as an eclipse cycle (see K. P. Moesgaard: "The full moon
serpent. A foundation stone of ancient astronomy?", Centaurus 24 (1980):
51-96), my reference to a 135-moon eclipse cycle among the ancient
inhabitants of the Canary Islands is absolutely correct.

As a matter of fact, the 135-moon eclipse cycle is a very ancient and
widespread eclipse cycle well known in different ancient cultures. A good
example can be found in Maya astronomy, since it is in the base of the
405-moon eclipse cycle of the Dresden Codex (405 = 3 x 135).

For a sound reference of its significance in the ancient world, see A. Aaboe
"Remarks on the theoretical treatment of eclipses in antiquity", Journal for
the History of Astronomy 3 (1972): 105-118.

Yours - Jose Barrios

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On 29/12/98 Moshe' Machover posed the following question:

> At 7:56 pm -0500 28/12/98, James A Landau wrote inter alia:
>
> Jose Barrios Garcia defended successfully (Apt cum Laude) his
> doctoral thesis, entitled "Number systems and calendars of the
> berber populations of Grand Canary and Tenerife in the 14th-15th
> centuries" at the Faculty of History (Department of
> Anthropology) of the University of La Laguna (Tenerife), on June 5,
> 1997.
>
> the thesis abstract:
[inter alia]

> The proposed calculus establish the octaeteris and the 135-moon
> eclipse cycle as basic periods of the acano.

Shouldn't this be 235?

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