With the exception of the Dee, which rises near Lake Bala in Wales, the rivers of Cheshire have their sources in the eastern or southern uplands. For eight months of the year moisture-laden winds blow from the sea across the Cheshire Plain and deposit their rains upon the hills. In the hilly country of the north-east, where the rainfall is greatest, the water is gathered and stored in a number of reservoirs in Longdendale; and the moist climate is the chief reason why this district is the seat of the cotton industry, for cotton threads become brittle in a dry atmosphere. In the valleys of the Tame and Goyt the abundance of fresh running water from the hills formerly caused many mills for the bleaching, dyeing and printing of calicoes to be erected on or near the streams. Nowadays, however, owing to the greater supply of water brought by pipes from a distance, mills are erected principally on the outskirts of the great towns and nearer the centres of population. Hence in the villages of the Goyt it is no uncommon sight to see the tottering walls of mills that have been abandoned and allowed to fall into ruin and decay. The combined waters of the Etherow, Tame, and Goyt form the Mersey at Stockport. Only the left bank of this river is in Cheshire. Moreover, for a large part of its course it has been 'canalized', so that it no longer flows between its natural banks, but down the artificial channel of the Manchester Ship Canal. The estuary of the Mersey, which is three to four miles across at its widest point, narrows at Birkenhead to a width of barely three-quarters of a mile. At this point the river is kept open to the largest vessels afloat by constant dredging. Here in the docks you may see ships of all nations, and generally one or more of our huge ocean greyhounds riding at anchor in mid-river or awaiting but the turn of the tide to take out their cargoes of human lives to distant lands. [Illustration: SOURCES OF RIVERS IN E. CHESHIRE] The Weaver, on the other hand, is wholly a Cheshire river, rising in the Peckforton Hills in the south-west of the county. The Mersey and the Weaver receive a number of tributaries, of which the Bollin and the Dane are the most important, from the eastern highlands, the high-crowned Shutlingslawe ... with those proud hills whence rove The lovely sister brooks the silvery Dane and Dove, Clear Dove that makes to Trent, the other to the West. At Northwich the Weaver becomes navigable as far as the Mersey.