He quotes what he calls “the well-known” letter of St. Jerome to two learned Celts, pointing out the errors in the vulgar copies; but Rohrbacher remarks that this letter was well-known only in the ninth century, for in ours it no longer exists. The whole letter of Floras is exceedingly valuable as evidence of the extraordinary learning and diligence bestowed on the correction of the Sacred Text.[106] Nevertheless, an examination of the catalogues of early monastic libraries, makes it clear that the study of Greek, if not wholly neglected, was exceptional, and certainly did not include any extensive acquaintance with ancient Greek literature. Among the books named as the favourites of St. Paschasius, we find the works of St. John Chrysostom; but in general the book collections are only rich in the Latin Fathers. Scotus Erigena evidently introduced a novelty when he translated the works of St. Denys the Areopagite, and the eagerness displayed by Louis the Debonnaire to possess a Latin version of the works of this author arose, perhaps, less from an interest in Greek letters, than from the opinion, then finding favour with Gallican scholars, which identified him with the Apostle of France.[107] The mention, however, of any Greek poets or philosophers is exceedingly rare. Homer, as has been said, had been brought into England by Archbishop Theodore, and the St. Gall library contained the works of Sophocles, but these are certainly exceptions, and we may conclude that a knowledge of the Greek language was a rare accomplishment, from the extreme complacency with which the possession of a very superficial smattering of it was often regarded. Hincmar, of Rheims, warns his nephew to avoid the foolish affectation of some, who pick a handful of Greek words out of their glossaries to adorn their pages and give them a learned look; a folly too common also with our native scholars. The sciences of arithmetic and geometry were probably taught in rather a meagre form, until the genius of Gerbert, in the tenth century, gave fresh impulse to these branches of learning. We have seen what difficulties attended their study in the days of St. Aldhelm; nevertheless the path of the young student was somewhat smoothed by pleasant devices, and the Anglo-Saxon masters quickened the brains of their pupils by problems and questions, some of which, such is the power of tradition, have kept their places in our own school-books. Arithmetical problems, such as the following, were propounded to the schoolboys of Alcuin and Rabanus: “The swallow once invited the snail to dinner; he lived just a league from the spot, and the snail travelled at the rate of one inch a day: how long was he before he dined?” Or, again: “An old man met a child; ‘Good day, my son,’ he said, ‘may you live as long as you have lived and as much more, and thrice as much as all that put together, and then if God give you one year more, you will be just a century old;’ how old was the boy?”