Before the great changes which took place in the inhabitants of Greece from the immigration of the Thesprôtians into Thessaly, of the Bœôtians into Bœôtia, and of the Dôrians and Ætôlians into Peloponnêsus, at a date which we have no means of determining, the Minyæ and tribes fraternally connected with them seem to have occupied a large portion of the surface of Greece, from Iôlkos in Thessaly to Pylos in the Peloponnêsus. The wealth of Orchomenos is renowned even in the Iliad;[296] and when we study its topography in detail, we are furnished with a probable explanation both of its prosperity and its decay. Orchomenos was situated on the northern bank of the lake Kôpaïs, which receives not only the river Kêphisos from the valleys of Phôkis, but also other rivers from Parnassus and Helicôn. The waters of the lake find more than one subterranean egress—partly through natural rifts and cavities in the limestone mountains, partly through a tunnel pierced artificially more than a mile in length—into the plain on the north-eastern side, from whence they flow into the Eubœan sea near Larymna:[297] and it appears that, so long as these channels were diligently watched and kept clear, a large portion of the lake was in the condition of alluvial land, preëminently rich and fertile. But when the channels came to be either neglected, or designedly choked up by an enemy, the water accumulated to such a degree, as to occupy the soil of more than one ancient town, to endanger the position of Kôpæ, and to occasion the change of the site of Orchomenos itself from the plain to the declivity of Mount Hyphanteion. An engineer, Kratês, began the clearance of the obstructed water-courses in the reign of Alexander the Great, and by his commission—the destroyer of Thêbes being anxious to reëstablish the extinct prosperity of Orchomenos. He succeeded so far as partially to drain and diminish the lake, whereby the site of more than one ancient city was rendered visible: but the revival of Thêbes by Kassander, after the decease of Alexander, arrested the progress of the undertaking, and the lake soon regained its former dimensions, to contract which no farther attempt was made.[298] [296] Iliad, ix. 381. [297] See the description of these channels or Katabothra in Colonel Leake’s Travels in Northern Greece, vol. ii. c. 15, p. 281-293, and still more elaborately in Fiedler, Reise durch alle Theile des Königreichs Griechenlands, Leipzig, 1840. He traced fifteen perpendicular shafts sunk for the purpose of admitting air into the tunnel, the first separated from the last by about 5900 feet: they are now of course overgrown and stopped up (vol. i. p. 115). Forchhammer states the length of this tunnel as considerably greater than what is here stated. He also gives a plan of the Lake Kôpaïs with the surrounding region, which I have placed at the end of the second volume of this History. See also _infra_, vol. ii. ch. iii. p. 391.