“ These hills are breached by the Medway in a, beautiful valley, in which lies Maidstone, generally much narrower than the upper. valley. The characteristic structure of this part of the valley is considered under the heading Downs. Below Maidstone the valley forms a perfect basin, the hills descending upon it closely above Rochester. Below this city the river enters a broad, winding estuary, passing Chatham, and at Sheerness joining that of the Thames, so that the Medway may be considered a tributary, and its drainage area of 680 sq. ”