There is a clear distinction between the characteristics of the stars of Perseus and those of the Gorgon's Head, which Ptolemy fails to acknowledge in his list of planetary natures. Since most astrologers follow Ptolemy, Algol, (the main star in the Gorgon's head) is usually described as like Jupiter and Saturn in influence; but in view of its widespread and overwhelmingly malevolent reputation Lilly was probably more correct when he likened it to Saturn and Mars. It is alleged to be the most unfortunate and dangerous star in the heavens and has a reputation for causing violence and unnatural death. Even Ptolemy remarked upon its influence in bringing 'death by decapitation or mutilation', when tied into the hostile aspect of Mars to the Sun or Moon.
The name Algol comes from the Arabic Al Ghul, the 'Ghoul' or 'Demon'. Usually it is classed as a white star but it has also been listed as red. It seems, always, to have been connected with death, tragedy and ****** violence: the Hebrews knew it as Rosh ha Satan, 'Satan's Head', and the Chinese as Tseih She, 'Piled-up Corpses'. According to Dr Lomer in Kosmobiologie Arabic commanders ensured that no important battle began when the light of Algol was weak.
In ancient times it was referred to as 'the Winking Demon' or 'the blinking eye of the Gorgon', because it is one of the most variable stars in the northern sky, alternating its brilliance from 2nd to 3rd magnitude in a particularly notable fashion due to its short cycle of variability which completes in three days. Most probably, its malefic reputation arose out of this variability, which threw a direct challenge to Aristotle's doctrine of the pure immutability of the heavens, by which celestial harmony was associated with perfect and constant motion. The inconstancy is caused by the fact that Algol is a binary system in which the brighter star is regularly eclipsed by its partner for a period of around 8 hours. Thus we get the ominous reference to an evil pulsating eye - a very powerful and provocative image and recently put to great effect by Tolkien as a representation of the evil Mordor in Lord of the Rings.
Lilly considered Algol to be one of the most portentous stars, noting its affliction as an indication of decapitation, hanging or danger to the head. In his system of scoring planetary strength, any planet within five degrees of Algol is detrimented by 4 points of debility. When placed with the Part of Fortune it threatens poverty or the loss of wealth, and with the 'significator of manners' it:
"begets in the Native a certaine dogged nature and violence, whereby he either procures sudden death unto himself, or is the cause of it to others".
Of the direction of the midheaven to this star Lilly writes:
It perplexes and casts the Native into extreame danger by reason of Murder, Man-slaughter, or the sudden death of someone or other, the Native being either author or assistant, it endangers the Head: if other Directions concurre in good, it gives the Native power of putting others to death; but I ever found it an ill Direction, even in mean mens Genitures.