xxxii MAX AND THE GLACIAL PERIOD. 



FIG. PAGE 



98. Section across the channel of the Stanislaus River . . 300 



99. Diagram showing effect of precession .... 308 



100. Map showing course of currents in the Atlantic Ocean . 314. 



101. Map showing how the land clusters about the north pole . 319 



102. Diagram showing oscillations of land-surface and ice- 



surface during the Glacial epoch 323 



103. Diagram of eccentricity and precession .... 333 



104. Map of the Niagara River below the Falls . . . 334 



105. Section of strata along the Niagara Gorge .... 336 



106. Map showing the recession of the Horseshoe Falls since 



1842 338 



107. Section of kettle-hole near Pomp's Pond, Andover, Mass. 345 



108. Flint-flakes collected by Abbe Bourgeois . . . .368 



MAPS. 



TO FACE PAGE 



Contour and glacial map of the British Isles . Frontispiece. 

 Map showing the glacial geology of the United States . . 66 

 Map of glacial movements in France and Switzerland . . 132 



