=A.D. 426.=--Augustine (Aurelius, Saint), the most prominent of the Latin Fathers of the Church, finishes his “De Civitate Dei,” which he began in 413, and which is considered the greatest monument to his genius. He was probably the most voluminous writer of the earlier Christian centuries. He was the author of no less than 232 books, in addition to many tractates or homilies and innumerable epistles (“Books and their Makers, during the Middle Ages,” Geo. Haven Putnam, New York, 1896, Vol. I. p. 3). In the “De Civitate Dei” he tells us (Basileæ, 1522, pp. 718–719) of the experiment alluded to herein at A.D. 1558. This had better be given in his own words (“De Civitate Dei,” lib. ii. cap. 4, Dod’s translation, Edinburgh, 1871): “When I first saw it (the attraction of the magnet), I was thunderstruck (_vehementer inhorrui_), for I saw an iron ring attracted and suspended by the stone; and then, as if it had communicated its own property to the iron it attracted and had made it a substance like itself, this ring was put near another and lifted it up, and, as the first ring clung to the magnet, so did the second ring to the first. A third and fourth were similarly added, so that there hung from the stone a kind of chain of rings with their hoops connected, not interlinking but attached together by their outer surface. Who would not be amazed by this virtue of the stone, subsisting as it does, not only in itself, but transmitted through so many suspended rings and binding them together by invisible links? Yet far more astonishing is what I heard about the stone from my brother in the episcopate, Severus, Bishop of Milevis. He told me that Bathanarius, once Count of Africa, when the Bishop was dining with him, produced a magnet and held it under a silver plate on which he placed a bit of iron; then as he moved his hand with the magnet underneath the plate, the iron upon the plate moved about accordingly. The intervening silver was not affected at all, but precisely as the magnet was moved backward and forward below it, no matter how quickly, so was the iron attracted above. I have related what I have myself witnessed: I have related what I was told by one whom I trust as I trust my own eyes.”