Tag: astrology

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Pseudo-Ptolemy’s Treatise on the 9 Types of Comets

Starting around the 13th century, various astronomical texts began making their way into Christian Europe. These texts were largely translated from Arabic.

Among them, was a text that was originally attributed to Ptolemy which discussed the character and astrological implications of comets. Scholars have since concluded that this text is not by Ptolemy, but it was still widely distributed.

This text is one of many that is under investigation for the Ptolemaeus Arabus et Latinus project. There they provide a scan of a manuscript in the collection of the British Library (Sloane 2030) as well as a transcription of the text.

However, there was no translation. As such, I have attempted my own which is placed below the fold.

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Almagest Book VI: Determining the Inclinations

And here we are. Final chapter of Book VI. Here, we’ll finish out Ptolemy’s discussion of the inclinations of eclipses. In the previous post, we discussed a few things we’ll need to determine that1, but we really haven’t discussed is what the “inclination” means. So I’ll begin by doing that as Ptolemy doesn’t really do a clear job of doing so. Continue reading “Almagest Book VI: Determining the Inclinations”

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Almagest Book VI: Horizon Diagram

In the previous chapter, we mentioned that one of the things we’ll need for Ptolemy’s weather prediction is the angle between the ecliptic and celestial equator as measured along the horizon. This is something we calculated back in II.2 and only now are we getting around to displaying a diagram to summarize it. So I’ll display the diagram here2 and discussion about it will be beneath the fold.

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Almagest Book VI: Angles of Inclination at Eclipses

The final few chapters of Book VI are rather odd. Now that we’ve completed the discussion of eclipse prediction, Ptolemy wants to do an “examination of the inclination which are formed at eclipses.” However, he doesn’t appear to provide any motivation for doing so. Toomer and Neugebauer both indicate that the actual reason was likely weather prediction3, but the Almagest doesn’t contain any information on how this is to be used. Neugebauer indicates that,

[T]he technical term connected with this problem is “prosneusis”…developed from the original meaning of the verb νευειν (to nod, to incline the head, etc…). According to the terminology of hellenistic astrology, the planets or moon can, e.g., give their consent by “inclining” toward a certain position, i.e., by being found in a favorable configuration.

However, aside from these astrological purposes, these last few chapters are essentially left as a free-floating bit of material. Continue reading “Almagest Book VI: Angles of Inclination at Eclipses”