One of the most singular, as well as most ancient, of the many forms and modifications of the cross is the "fylfot." It is found, probably as a disguised form of the cross, on the tombs in the catacombs. {61} Its use illustrates the adoption by the early Christians, as in the case of the tau-cross, of prechristian symbols. By its employment they simply "diverted to their own purpose a symbol centuries older than the Christian era, a symbol of early Aryan origin, found in Indian and Chinese art, and spreading westward, long before the dawn of Christianity, to Greece and Asia. It was on the terra-cotta objects dug up by Dr. Schliemann at Troy, and conjectured to date from 1000 to 1500 B.C." It is thought to represent in heathen use a revolving wheel, the symbol of the great sun-god, or to stand for the lightning wielded by the omnipotent deity, Manu, Thor, or Zeus. The Christians saw in it a cross concealed from the eyes of their heathen enemies. The fylfot is frequently found in the Greek Church on the vestments of the clergy. The Greek fret or key pattern, with which all are familiar, is a decorative development of the fylfot. [Illustration: Fylfot] Another interesting form of the cross is that known as the "cross of Iona" or "Irish cross." It is said to be the earliest form known in {62} Great Britain and Ireland. The antique wayside crosses are of this shape. "Because this style of cross partakes more of Greek character than of Latin, it has been contended that it argues an Eastern rather than Western origin for the introduction of Christianity into Great Britain." The circle is the emblem of eternity, as having neither beginning nor end, and when combined with the cross, as in this form, it speaks of the perpetuity of the Christian faith and the eternity of its hope. [Illustration: Irish cross] The "St. Andrew's cross," in form like the letter X, conveys the idea of humility as well as that of suffering. When St. Andrew was condemned to be crucified, he begged that his cross might be unlike that on which his Lord had died, not deeming himself worthy to die on a cross of the same form as that on which He had suffered. [Illustration: St. Andrew's cross] There is a cross peculiar in form, and known as the "Canterbury cross." It is in the shape of the letter Y, and is usually seen only upon the vestments of the clergy. The ornamentation of the chasuble is commonly of this form. It is embroidered on the chasuble of St. Thomas of Canterbury, which is still preserved in the Cathedral {63} of Sens, in France. Its shape brings to mind the inclination of our Saviour's arms--the lifting up of His hands--as He offered Himself in sacrifice on Calvary. _Symbols of the Holy Trinity._--The equilateral _Triangle_ is perhaps the most familiar emblem of the Holy Trinity. The equality of the three divine Persons in the Godhead is represented by the equal sides or the equal angles of the triangle. [Illustration: Triangle]