Up to the tenth century, the age of Gerbert, a knowledge of Geometry in our sense of the term hardly existed in Western Europe. In fact the term seems to have been used in its etymological meaning and not in the sense the Greeks understood it. We have found no evidence to warrant the assumption that Euclidean Geometry was taught in those early Irish monastic schools. But on the other hand an examination of the characteristic Irish style of ornament suggests that the Irish artist had at least a good working knowledge of practical Geometry. Possibly the amount of knowledge of theoretical Geometry did not extend beyond the narrow[467] limits of the works of Capella,[468] Cassiodorus,[469] and Isadore of Seville[470]—writers well known to Irish scholars as we have seen. GEOGRAPHY: If the mathematical science of Geometry was still undeveloped in the West geography, topography and cosmography made up the deficiency. It was but natural that the Irish monks, the greatest voyagers of their time, should be interested in the study of foreign lands. We have an instance of this in the case of Adamnan who wrote his _De Locis Sanctis_ from the dictation of Arculfus, a Frankish bishop who had visited Palestine.[471] Bede based his work bearing a similar name on Adamnan’s volume. This work of Adamnan with that of Bede continued to be the only source of information of the geography, Christian antiquities, and customs of Palestine until the Crusades gave Western Europe a more acute and active interest in that distant, inhospitable region.[472] We have referred to a curious geographical poem[473] which was evidently used as a text in the monastic schools of Ireland. It contained probably all the geography that was taught prior to the tenth century. The tenth century map of the world[474] drawn in England for an Anglo-Saxon is supposed to have been the work of an Irish artist and further illustrates the state of geographical knowledge of the times. The more ambitious treatise of Dungal, _De Mensura Orbis Terrarum_, which will be described in the next chapter, marks a new departure in geographical texts—hitherto mere compendiums—inasmuch as it introduces new matter, is more critical, “up-to-date” and altogether a commendable attempt for a ninth century scholar.