Irish Knowledge of Science
7. The Knowledge of Science.
The pure and physical sciences, so far as they were known in the Middle Ages, were taught in the schools and colleges of Ireland. The success of the home teaching appears plain from the distinction gained by several Irishmen on the Continent for their knowledge of astronomy, as will be pointed out farther on: knowledge not acquired abroad, but brought from their native schools.
The Irish scholars understood astronomy; and we have still several ancient treatises in the Irish language, well illustrated with astronomical diagrams. In the first poem of the Saltair-na-Rann, written probably about A.D. 1000, is an account of the creation of the world, with a short description of the universe, showing a knowledge of the theories—some right, some wrong—then prevalent.
Facsimile (by hand) of a diagram in an astronomical tract (about A.D. 1400) in the Royal Irish Academy, Dublin. The lower small circle is the sun (sol): the middle small circle is the earth (terra), throwing its shadow among the stars.
The various astronomical cycles were perfectly understood and were familiarly applied to calculations in connexion with chronology and the calendar. Among the many Irish writers who have dealt with those matters may be mentioned Augustin, already referred to (p. 150), who wrote his Essay on the wonders of the Bible, while residing at Carthage. The Irish writers were well acquainted with the solstices, which they called by the descriptive native Irish name grien-tairisem—so given in an eighth or ninth-century gloss in Zeuss—meaning 'sun-standing': and they correctly state that the summer solstice occurs on the 21st June. They had a native name for the autumnal equinox (21st September) which was descriptive and scientifically correct: Deiseabhair na grene [Deshoor-na-grena], literally the 'southing or going south by the sun' (i.e. going south of the equinoctial), from deas 'south.'
All this shows that they understood the apparent annual motion of the sun along the ecliptic, half the year north, and the other half south of the equinoctial, and that at the autumnal equinox it enters on the south part of its course. So, also, the real movement of the moon, and the apparent motion of the sun, round the earth—both from west to east—were well understood, as appears from a remark of one of the commentators on Dallan's "Amra on Columkille," that "the moon is before the sun from the first to the fifteenth [of the moon's age], and after the sun from the fifteenth to the first"—a perfectly correct statement.
Irish scholars understood the use and construction of the sundial, for which two words were used solam,which is a native term, and soiler, which is borrowed and shortened from the Latin, solarium, 'a sundial.' Besides this there is a small Irish MS. book in the monastery of St. Gall in Switzerland, written by some scholarly Irish monk residing there in the eighth century, containing remarks on various scientific subjects, such as the Cycles, the age of the world, and, among others, on the sundial.
Virgil or Virgilius, abbot of Aghaboe in the present Queen's County, who went to the Continent A.D. 745, and became bishop of Salzburg, was one of the most advanced scholars of his day. Pepin, Mayor of the Palace, subsequently king of France, became greatly attached to him, and kept him in the palace for two years. Virgil taught publicly—and was probably the first to teach—that the earth was round, and that people lived at the opposite side—at the antipodes. His Irish name was Fergil, which, in a modified form, is common in Ireland to this day (O'Farrell): and he is commonly known in history as Fergil the Geometer.
We have a remarkable testimony to the reputation of Irishmen on the Continent for secular and other learning in those early ages, in the well-known letter written to Charlemagne by the Irish monk Dungal, which came about in this way. It having been stated that two solar eclipses had occurred in one year, A.D. 810, the emperor selected Dungal, who happened to be then in France, as the scholar considered best able to explain such an unusual occurrence, and requested him to do so. Dungal's reply, which explains the matter, so far as the state of knowledge in his time enabled him, shows that he knew of the inclination of the plane of the moon's orbit to that of the ecliptic; and he sets forth the astronomical principle that for an eclipse—whether of sun or moon—to occur, it is necessary that the moon should be in the plane of the ecliptic. This Dungal subsequently resided in Italy, where he became a celebrated teacher, drawing pupils from all the surrounding cities; and he also wrote learnedly on ecclesiastical subjects.
In the year 825, an Irish scholar and traveller named Dicuil wrote a complete Geography of the world, so far as it was then known, which is still extant on the Continent, and which was published in several editions in the eighteenth century by German and French editors.
When learning had declined in England in the ninth and tenth centuries, owing to the devastations of the Danes, it was chiefly by Irish teachers it was kept alive and restored. In Glastonbury especially, they taught with great success; and we are told by many English writers that "they were skilled in every department of learning, sacred and profane"; and that under them were educated many young English nobles, sent to Glastonbury with that object. Among these students the most distinguished was St. Dunstan, who, according to all his biographers, received his education, both Scriptural and secular, from Irish masters there. One writer of his Life, William of Malmesbury, states that Dunstan studied diligently arithmetic, geometry, astronomy, and music under the Irish teachers, and adds that these sciences were held in great esteem and were much cultivated by them. Even the general mass of intelligent people made use of simple astronomical observations in daily life. Cuculainn, sitting at a feast, says to his attendant:—"Go out, my friend, Loeg, observe the stars of the air, and ascertain when midnight comes" [when Cuculainn would have to leave]. And Loeg did so, and came back at the proper moment to announce that it was midnight. This record shows that all intelligent people of those times could roughly estimate the hour of night throughout the year by the position of the stars: a sort of observation not at all simple, inasmuch as the positions of the stars at given hours change from month to month.
The age of the moon (aes esca) is mentioned in Cormac's Glossary, as well as in many other ancient authorities, as a matter quite familiar: and in the Saltair na Rann it is laid down that every intelligent person ought to know the following five things:—The day of the solar or ordinary month; the age of the moon; the time of the flow of the tide [for those living near the sea]; the day of the week; and the chief saints' festival days.
These are a few illustrations—scattered and fragmentary indeed—of the eminence of ancient Irish scholars in science. But the materials for final judgment are not yet available; they are still hidden away in manuscripts among libraries all over Europe. When they are fully brought to light, then, and not till then, we shall be able to accord something approaching the full meed of justice to the learned men of ancient Ireland.
END OF CHAPTER VII.