Reviews — Mackintosh! s Scenery of England ^ Wales. 469 



their caves, grooves, arches, needles, stacks, and other varieties of 

 cliff-architecture ; and, lastly, the forms of maritime inlets, are suc- 

 cinctly treated of. 



Some pages are next occupied with remarks on the Denudation 

 that must have occurred during the "Glacial" and other sub- 

 mergences of England and Wales, inasmuch as the gravels and 

 shingle of the "Glacial" and "Post-glacial" periods remain as 

 visible debris of sea-worn lands. But it appears impossible as yet 

 to determine from these so-called "Drifts" how many emergences 

 and submergences there were, or how much wrecking of the land 

 the mass of detritus really indicates ; some of the oldest of these 

 " drifts" may have been shifted again and again, " serving as shore- 

 accumulations for seas in the depths of which some of our finer 

 sedimentary strata may have been deposited," just as the pebbles of 

 earlier shingles were left to rest awhile in old conglomerates, to be 

 loosened and sent again by wave or stream to another and perhaps 

 another place of heaping-up or of out-spread driftage. 



Holding in mind the main object of the book, namely, the ex- 

 planation of land scenery, the author then seeks to apply the facts 

 of marine scenery, already studied, to the explanation of inland 

 features. He prefaces this part with some well founded re- 

 marks on the extent to which different rock-structures give rise to 

 difference of landscape ; relative (not absolute) hardness of the 

 several strata, and their variously horizontal, inclined, or vertical 

 positions being the causes of differences in surface -aspects, combined 

 with lithological conditions favourable or otherwise to the growth 

 of this or that kind of tree and herbage. Some raised sea-beaches 

 and inland terraces, chiefly in the south of England, are noted, and 

 a reference made to their being evidences of sudden displacement of 

 the land whilst being fed upon by the sea. Inland escarpments 

 come next, and occupy six interesting chapters well worth reading 

 and careful consideration. The history of the Wealden Denudation 

 is concisely handled, but would be more perfect if allusion had been 

 made to Mackie's bold suggestion of a tidal stage in the long process 

 of that old excavation, when the North Downs still reached across, 

 as an isthmus, to the chalk of France, and the checked tide swept 

 in and out along the curving cliffs (" Geologist," 1860, p. 203). But 

 not only the Cretaceous escarpments, but those in the Oolitic counties, 

 and those of the Lias, the New Eed Sandstone, Coal-measures, Mill- 

 stone-grit, Mountain-limestone, Old Ked Sandstone, and the Silurian 

 and Cambrian rocks, are brought forward with much care, and often 

 shown in woodcuts. Then come the granite tors and rock -basins, 

 the coombs (cwms) and tarns, and the questions as to how far they 

 are generally and individually due to the rain or springs or glaciers, 

 or to the sea and coast-ice. Conical isolated hills are briefly noticed ; 

 and then the marine origin of plains, both of upland plateaux and 

 of many low-lying plains, at least as regards their origiual general 

 flatness, is insisted on, apparently with justice. The classification 

 and origin of valleys, gorges, gulleys, and passes, are dealt with in 

 two chapters, full of interesting discussion, based on observations 



