Men were not so well agreed in the Middle Ages regarding differences of climate between East and West as regarding those between North and South. Bartholomew Anglicus[797] believed the West to be cold and damp and the East hot and dry, an opinion unlike that of William of Conches in that it may well have been based on actual observation rather than on theory. Giraldus Cambrensis in the _Topographia Hiberniae_ gives a long discourse[798] on climatic and other differences between the Orient and Occident, in which his main contention is that, though the air is clearer, finer, and more “subtle” in the East, the stormy and damp climates of the West are better for the health. The true climate of the Orient—that is of the Levant—had been made known to the Occidental world through the Crusaders, who often dwelt with insistence on its disagreeable and injurious qualities, especially the heat, dust, and thirst of the Syrian summer, which dried cisterns and carried disease and death in its train. In the East, Giraldus says, everything threatens the traveler, and he writes a word of warning against doing many of those very things which the modern wanderer in the Levant knows to be imprudent: such as going uncovered, sitting on rocks, or overeating.[799] TOPOGRAPHIC INFLUENCES UPON CLIMATE _The Sea_ During our period we find several descriptions of local climatic conditions and of variations due to topographic features like sea and mountains. A vivid impression of the wild marine weather of the North Atlantic off the coast of Ireland is given us in the narrative of St. Brandan’s wanderings. The saint and his companions were forced to remain three months on an island because of storms with furious gales, rain, and hail.[800] Giraldus Cambrensis[801] pictures the turbulent climate of Ireland, an isle surrounded by vast seas, unprotected and exposed to all the blasts. He was especially struck by the thick and rainy westerly gales, Zephyr and Corus, which bend over the trees in the seaward parts of the island. However violent the winds, Giraldus maintained that Ireland is the most temperate of all lands:[802] snow there is infrequent and when it comes lasts but a short while. Though cold weather accompanies all the winds, it never becomes too cold, and green grass grows in the pastures at all times of year. Yet so constant is the dampness, so prevalent the rain and clouds, that a clear day is rare indeed. _Mountains_