The _Trefoil_ is also an emblem of the Trinity. It is a representation of the common clover, or shamrock, as the Irish call it. The legend of the conversion of Ireland says that St. Patrick was preaching on the hillside, and wishing to illustrate from nature the sublime doctrine of the Trinity to his pagan hearers, he bent down and plucked a piece of shamrock at his feet, and held it up to show how what was three, in one sense, might be one in another. [Illustration: Trefoil] The unity of the Persons in the one Godhead is sometimes represented by intersected triangles, or by the trefoil placed under a triangle. The truth of the Trinity is also suggested by any {64} threefold arrangement in the various forms of the ornamentation. The figure known as the _triquetra_, made by the interlacing of three portions of circles, is also symbolical of the Holy Trinity. This is a very ancient emblem, and is found with frequency upon the stone crosses erected in the early days of Christianity in Great Britain. It is sometimes used in ornamentation of the dress of our Lord or of the Evangelists. [Illustration: Intersected triangles. Trefoil placed under a triangle. Trequetra.] From the thirteenth century we have the symbol of the equal and interlacing _Circles_. "The three equal circles symbolize the equality of the three Persons in the Trinity, the binding together in one figure the essential unity, while the circular form signifies a never-beginning, never-ending eternity." The word _trinitas_, used in this symbol, may itself {65} be divided into three syllables. One of these syllables is placed in each circle; but they have no perfect meaning, and will not form any word, unless united. In the space left vacant by the intersection of the circles the word _unitas_ is placed. [Illustration: Interlacing circles] From the sixteenth century we have another device setting forth the doctrine of the Trinity. This is a triangle terminating at the corners in three circles, and in the center another circle with lines connecting it with the circles at the corners. A legend is combined with the figure, which serves to explain it. The English equivalent of the Latin words is as follows: _Deus_, God; _Pater_, the Father; {66} _Filius_, the Son; _Sanctus Spiritus_, the Holy Ghost; _est_, is; _non est_, is not. [Illustration: Triangle and circles] _Symbols of the father Almighty._--For the first four centuries the only symbol employed to represent God the Father Almighty was a _hand_ issuing from clouds, or reaching down in benediction from heaven. A symbol of much later origin is a triangle with the word "Jehovah," in Hebrew letters, inscribed within it and placed in the center of a radiating circle, or halo, symbolic of eternity.