gradually formed which attached itself specially to the tools used by Masons, and thus formed the basis of Moral teaching--"to act on the Square," "to keep within the bounds of the Compasses," "to be Level in all your dealings," &c., &c. A wonderful, new, and Mystical form of Symbolism was opened to them with the advent of Geometry. The text-book of Geometry was unknown throughout the whole of Europe, omitting Spain, from the sixth to the beginning of the twelfth century; it was, as I have pointed out, well known in Greece before our Era, and continued to be so up to about the sixth century A.D. In the fourth century lived the Greek, Theon of Alexandria, so well known for his edition of Euclid's Elements, with notes, from which all Greek MSS. which first came to light in the sixteenth century were taken, being entitled [Greek: ek ton Theonos synousion], "from Theon's Lectures," and which he probably used as a text-book in his classes; but these MSS. had all been lost before the seventh century, and were not recovered again until the sixteenth century, when Simon Grynaeus, the greatest Greek scholar on the Continent, and companion of Melancthon and Luther, discovered a copy in Constantinople. Meanwhile, Theon's edition had been translated into Arabic, and thus preserved by the Mohammedans, and it was only at the beginning of the twelfth century that Athelard of Bath, who had been travelling in the East, came to study at Cordova, in Spain, and there found the Arabic MSS. of Euclid; these he translated into Latin, and this translation must have come into the hands of the patrons of the building craft at the very time when the Gothic style had its origin; it was the only Latin translation known in Europe, and was, some centuries later, the text-book of the first printed edition of Euclid.