If we pass to more modern times we find mention of AEtna by Dante, Petrarch, Cardinal Bembo, and other middle age writers. In 1541 Fazello wrote a brief history of the mountain, and described an ascent. In 1591 Antonio Filoteo, who was born on AEtna, published a work in Venice, in which he describes an eruption which he witnessed in 1536. He asserts that the mountain was then, as now, divided into three "regions"--the first very arid, rugged, uneven, and full of broken rocks; the second covered with forests; and the third cultivated in the ordinary manner. The great eruption of 1669 was described at length by the naturalist Borelli in the year of its occurrence, and a brief account of it was given by the Earl of Winchelsea, English ambassador at Constantinople, who was returning home by way of the Straits of Messina at the time. As the eruption of 1669 was the most considerable one of modern times, it attracted a great deal of attention, and was described by several eye-witnesses. The height of AEtna has been often determined. The earlier writers had very exaggerated notions on the subject, and a height of three and even four miles has been assigned. It must be borne in mind that the cone of a volcano is liable to variations in height at different periods, and a diminution of more than three hundred feet has occurred during the course of a single eruption of AEtna, owing to the falling of the cone of cinders into the crater. During the last sixty years, however, the height of the mountain has been practically constant at ten thousand eight hundred and seventy-four feet. There are two cities, Catania and Aci Reale, and sixty-three towns or villages on Mount AEtna. It is far more thickly populated than any other part of Sicily or Italy. No less than 300,000 people live on the mountain. A remarkable feature of AEtna is the large number of minor cones which are scattered over its sides. They look small in comparison with the great mass of the mountain, but in reality some of them are of large dimensions. The best period for making the ascent of AEtna is between June and September, after the melting of the winter snows, and before the falling of the autumnal rains. In winter there are frequently nine or ten miles of snow stretching from the summit downward, the paths are obliterated, and the guides sometimes refuse to accompany travelers. Moreover, violent storms often rage in the upper regions of the mountain, and the wind acquires a force which it is difficult to withstand, and is at the same time piercingly cold.