Features in and about the Niagara gorge—The drilling of the gorge—The present rate of recession—Future extinction of the American Fall—The captured Canadian Fall at Wintergreen Flats—The Whirlpool Basin excavated from the St. David’s gorge—The shaping of the Lewiston Escarpment—Episodes of Niagara’s history and their correlation with those of the glacial lakes—Time measures of the Niagara clock—The horologe of late glacial time in Scandinavia—Reading references 352 CHAPTER XXVI LAND SCULPTURE BY MOUNTAIN GLACIERS Contrasted sculpturing of continental and mountain glaciers—Wind distribution of the snow which falls in mountains—The niches which form on snowdrift sites—The augmented snowdrift moves down the valley: birth of the glacier—The excavation of the glacial amphitheater or cirque—Life history of the cirque—Grooved and fretted uplands—The features carved above the glacier—The features shaped beneath the glacier—The cascade stairway in glacier-carved valleys—The character profiles which result from sculpture by mountain glaciers—The sculpture accomplished by ice caps—The Norwegian tind or beehive mountain—Reading references 367 CHAPTER XXVII SUCCESSIVE GLACIER TYPES OF A WANING GLACIATION Transition from the ice cap to the mountain glacier—The piedmont glacier—The expanded-foot glacier—The dendritic glacier—The radiating glacier—The horseshoe glacier—The inherited-basin glacier—Summary of types of mountain glacier—Reading references 383 CHAPTER XXVIII THE GLACIER’S SURFACE FEATURES AND THE DEPOSITS UPON ITS BED The glacier flow—Crevasses and séracs—Bodies given up by the _Glacier des Bossons_—The moraines—Selective melting upon the glacier surface—Glacier drainage—Deposits within the vacated valley—Marks of the earlier occupation of mountains by glaciers—Reading references 390 CHAPTER XXIX A STUDY OF LAKE BASINS Fresh water and saline lakes—Newland lakes—Basin-range lakes—Rift-valley lakes—Earthquake lakes—Crater lakes—Coulée lakes—Morainal lakes—Pit lakes—Glint or colk lakes—Ice-dam lakes—Glacier-lobe lakes—Rock-basin lakes—Valley moraine lakes—Landslide lakes—Border lakes—Ox-bow lakes—Saucer lakes—Crescentic levee lakes—Raft lakes—Side-delta lakes—Delta lakes—Barrier lakes—Dune lakes—Sink lakes—Karst lakes: _poljen_—Playa lakes—Salines—Alluvial-dam lakes—Résumé—Reading references 401 CHAPTER XXX THE EPHEMERAL EXISTENCE OF LAKES Lakes as settling basins—Drawing off of water by erosion of outlet—The pulling in of headlands and the cutting off of bays—Lake extinction by peat growth—Extinction of lakes in desert regions—The rôle of lakes in the economy of nature—Ice ramparts on lake shores—Reading references 426 CHAPTER XXXI