... wherein
the Divinity and, more rarely, the Blessed Virgin are represented,
has no reference, except in name, to a fish, but represents the
Almond, the symbol of Virginity and self-production."

The Vesica Piscis, and its name, is intimately connected with the
discovery, by Augustus Caesar in the century preceding our Era, as
narrated by Baronius, of a prophecy in one of the Sibylline books,
foretelling "a great event coming to pass in the birth of One who
should prove to be the true 'King of Kings,' and Augustus Caesar
therefore dedicated an altar in his palace to this unknown God."
Eusebius and St. Augustine inform us that the first letter of each
line of the verses from the Erythrean Sibyl containing this prophecy,
formed the word [Greek: ICHTHYS] (a fish), and were taken as
representing the sentence: [Greek: Iesous Christos Theou Huios
Soter]("Jesus Christ, the Son of God, the Saviour"). Based upon this
discovery arose that extraordinary enthusiasm, during the second,
third, and fourth centuries, for hunting up further prophecies in
Pagan sources, resulting in a great number of Sibylline verses being
invented, giving the minutest details in the Life of our Lord. These
fabrications seem to have been at that time generally accepted by the
masses as true prophecies, though we know now that they were written
some centuries after the events they were supposed to foretell.

Let us now return to the Vesica Piscis. In the paintings and
sculptures of the Middle Ages, we find it constantly used to
circumscribe the figure of the Saviour, especially whenever He is
represented as judging the world and in His glorified state. Many
beautiful examples of this in Anglo-Saxon work of the tenth century
may be seen in King Edgar's Book of Grants to Winchester Cathedral and
the famous Breviary of St. Ethelwolfe. Numerous illustrations of these
and other pictures of the Middle Ages, as also diagrams of the
properties of the Vesica Piscis, can be seen in the volume I have
already referred to dealing fully with this subject.

The building fraternity was a purely Christian community; the First
Crusade raised a great enthusiasm for building Christian Churches, and
brought in large gifts of money for that purpose. Up to 1140 Norman
Architecture held sway, having the "Square" for its unit, its greatest
symbol being the _Gnomon_, representing knowledge; but about that
time, as we have seen, arose from the study of Geometry, the head of