380 Notices respecting New Books, 



special study. The nature, characters, and distribution of the 

 till ^boulder-clay) and erratics, striated rock-surfaces, rock- 

 basins, kaims and escars, beds of arctic shells, and the local alter- 

 nations of sands, gravels, clays, and lignites with the till, have 

 readily attracted the attention of geologists, and the consideration 

 of their probable origin fully occupies the philosophic mind and 

 feeds the scientific imagination. As similar natural features 

 abound in other parts of the world, scientists of many sorts, 

 having concluded that ice must have been the chief agent con- 

 cerned with these phenomena, have carefully observed its various 

 physical conditions, and have invented many hypotheses about its 

 movements and their results. The compilation of these facts and 

 opinions, here offered by the Author, is naturally affected by his 

 own predilections and conscientious beliefs, which occasionally 

 lead him to oppose or ignore some even late researches on ice- 

 fields and superficial drifts. 



The " List of Authors quoted or referred to " (about 580) at 

 pages 832-838 indicates the wide extent of the literature to be 

 dealt with ; and Prof. J. Geikie intimates with truth that the list 

 does not exhaust what has been published about the facts and 

 inferences relating to glacial phenomena and the former existence 

 of wide-spread and intense action of Ice on some parts of the 

 Earth's surface. 



In the first (1874) and second (1878) editions of this book, 

 " The Great Ice-Age and its relation to the Antiquity of Man," 

 Scotland supplied, as now, the typical facts and phenomena ot a 

 Glacial region, with its subsequent (Post-glacial) conditions; and, 

 as great changes of climate seemed to be involved in that geo- 

 logical history, these were considered on the basis then regarded 

 as the best available. Clearer recognition of leading facts, and 

 their more perfect explanation, have much modified the hypotheses 

 that were then received as good and useful ; and the Author 

 in this, the Third Edition, endeavours to give his opinion clearly 

 on the results both of the new and extended examinations of the 

 physical phenomena, and of many criticisms on the one hand, and 

 helpful suggestions on the other. 



In the order of the subject-matters of the book, the glacial 

 deposits seen in Scotland come first, with the boulder-clay, its 

 composition, relative position, special characters, and local features. 

 Various modes of its origin, hypothetic-ally advanced, whether by 

 violent aqueous agency, or by the mediation of glaciers and ice- 

 bergs, are dealt with ; and a careful account is given of glaciers, 

 and of the modes and results of their action on the surface of the 

 ground. 



Chapter IV. is devoted to icy Greenland and its supposed 

 constitution of separate islands ; and treats of Arctic glaciers, 

 with icebergs, foot-ice, and sea-ice, and the littoral accumulations 

 of earthy and stony debris. Tnese are illustrative of much of 

 the ice-work which has modified the surface of Scotland. 



The glacial origin of the Till being accepted, there follows a 



