The importance of regulating the floods just referred to, and of preventing the sudden overflow of the waters to the destruction of the cultivated fields, may readily be imagined. The ancient Greeks made an effort to accomplish this task. To the east of the large Lake of Copais there is another lake basin, about one hundred and thirty feet lower, and encompassed by precipitous rocks, incapable of cultivation. This basin, the Hylice of the Bœotians, appears to be made by nature for receiving the superabundant waters of the Copais. The remains of a canal may still be traced in the plain, which was evidently intended to convey into {52} it the floods of the Copais, but it appears never to have been completed. No doubt care was taken to keep open the various _katavothras_, or subterranean channels, through which the waters of the Copaic lake discharge themselves into the sea. One of these, on the north-western shore of the lake, and close to the rock of Orchomenus, swallowed up the river Melas, and conveyed its waters to the Gulf of Atalanta. Farther to the east other subterranean channels flow towards Lakes Hylice and Paralimni, but the most important of these channels are towards the north-east, in the Gulf of Kokkino. In that extreme angle of the lake, the veritable Copais, the waters of the Cephissus rush against the foot of Mount Skroponeri, and are swallowed up by the ground so as to form a subterranean delta. To the south there is a cavernous opening in the rock, but this is merely a sort of tunnel passing underneath a promontory, and, except during the rainy season, it may be traversed dry-shod. Beyond this, another opening swallows up one of the most important branches of the Cephissus, which makes its reappearance in the shape of bounteous springs pouring their waters into the sea. Two other branches of the river disappear in the rocks about a mile farther north. They join soon afterwards, and flow northwards beneath the bottom of a sinuous valley. The old Greek engineers dug pits in this valley, which enabled them to descend to the subterranean waters, and to clear away obstructions interfering with their flow. Sixteen of these pits have been discovered between the opening of the katavothra and the place where the waters reappear. Some of these are still thirty to one hundred feet in depth; but most of them have become choked up with stones and earth. These ancient engineering works, which Crates vainly endeavoured to restore in the time of Alexander, may possibly date {53} from the mythical age of King Minyas of Orchomenus,[15] and the successful draining of these marshes may account for the well-filled treasury of that king spoken of by Homer. Thus the ingenuity of the Homeric age had succeeded in accomplishing a work of the engineering art which baffles our modern men of science ! [Illustration: PEASANTS FROM THE ENVIRONS OF ATHENS.] * * * * *