Centaur
The Centaur, a combination of male bust with Horse body and legs, was an embodiment of the Thessalonian horsemen. The Epic sculptures of the Metopes of the Parthenon are illustrative of the conflict between the Centaurs, and the Lapithæ, caused by the rudeness of the former when entertained as guests.
The Circle
The Circle, originally a sun sign, has been invested with symbolic meaning from the earliest antiquity, the general significance being that of Power, or Sovereignty; a significance which also applies to its employment as the crown, orb and nimbus.
In Egyptian art, the circular disc, orb or globe, is accompanied by two asps, and spread wings as a symbol of ever-present sovereignty with the power of life and death. The same meaning being expressed in the Assyrian version, which is similar in form, but with the bow-string substituted for the asps.
The Nimbus, Aureole, or Halo originally symbolised Power and Authority, not Sanctity, and its employment in Christian art was anticipated in pagan times.
It was adopted by the early Christians to express Divinity, or as an indication of holiness, and is usually in the form of a disc. That of the three persons of the Deity has three rays issuing from the centre, and sometimes is triangular in form.
The Nimbus of the Virgin Mary is circular, nearly always elaborated, but not tri-radiated. Those of saints and apostles are circular, more or less ornamented. The Aureole in the form of the Vesica Piscis is sometimes used to envelop the whole figure.
Symbols of the Trinity
Three circles interlacing or in the form of a trefoil are employed as emblems of the Trinity, as is also the equilateral triangle.