NA JURE 



553 



THURSDAY, OCTOBER 5, 1905. 



MODERN GEOLOGISTS AND THE " OLD 



MASTERS." 



Ice or Water. Another Appeal to Induction from 



the Scholastic Methods of Modern Geology. By 



Sir Henry H. Howorth, K.C.I.E., D.C.L., F.R.S., 



V.P.S.A., F.G.S. Vol. i. Pp. xlvi + S36. Vol. ii. 



Pp. viii + 498. (London : Longmans and Co., 



1905.) Price 325. net. 

 'T' HE two volumes before us must be regarded as 

 parts of a complete work in which the author 

 has set himself the task of disproving the usually 

 accepted glacial theory. As he himself says in his 

 preface, " the two volumes now published contain a 

 large part of, though not all, my supplementary 

 arguments against the glacial theory ; a portion 

 being still reserved for a succeeding volume which 

 will also contain an enlarged presentation and justifi- 

 cation of the theory I substituted for it in my 

 ' Glacial Nightmare,' namely, the diluvial theory." 



In the volumes under review the subject-matter 

 may be considered under three heads : — (i) the 

 theories which have been proposed to account for 

 Glacial periods ; (2) the efficiency of water as an agent 

 of erosion ; (3) the capacity of ice to produce the effects 

 which have been assigned to it by modern geologists. 



(i) Theories of an Ice Age. — The four opening 

 chapters of the first volume are devoted to a criticism 

 of the various theories, astronomical and geo- 

 graphical, which have been put forward in attempts 

 to solve the problem of the Great Ice .\ge and of 

 former periods of glaciation. Sir Henry is ever 

 skilful in detecting the weak points in his opponents' 

 armour, and here, as in his book on the " Glacial 

 Nightmare," he has an imposing array of objections 

 raised by others and himself to the various explan- 

 ations which have been offered. 



Our present inability to offer any adequate explan- 

 ation of the Glacial period seems to be largely recog- 

 nised ; as Prof. Chamberlin has said, "The riddle 

 remains to be read." This grieves the author greatly, 

 perhaps unduly. 



" It is not encouraging," he says, " to read of a 

 succession of failures by men of parts and ingenuity 

 in futile efforts to solve what is apparently an in- 

 soluble problem; to measure the waste of thought 

 and time and oil involved in these efforts of the 

 geological Sisyphus to roll the glacial snowball on 

 to some stable foothold, and to see it roll down the 

 hill in every case into the abyss where so many 

 scientific hopes and efforts lie buried." 



But is the waste so complete as the author seems 

 to imply? Though the riddle is not yet read, the 

 number of facts which have been garnered during 

 the process of testing the inadequate explanations 

 remain for use when seeking the correct solution, 

 and many a minor point has already been settled. 



The occurrence of Glacial periods is not the only 



climatic problem to which the geologist is without 



clue. We have not yet explained the existence of 



beds containing rich floras in Greenland. To the 



NO. 1875, VOX. 72] 



ordinary geologist the evidence for a Glacial period is 

 as strong as that for the former occurrence of warmer 

 conditions in Greenland, and he is hardly likely to 

 reject the evidence in the former case any more than 

 in the latter, simply because he has not yet arrived 

 at an adequate explanation of the phenomena. 



(2) The Efficiency of Water as an .igent of Erosion. 

 — The author devotes several chapters to a discussion 

 of the potency of the various agents of subaerial and 

 marine erosion under existing conditions, and refuses 

 to recognise the efficiency of these agents to do the 

 work claimed for them by the great number of living 

 geologists. He supports his arguments by a large 

 number of quotations from various writers, ancient 

 and modern, great and small. But we look in vain 

 for any recognition of the principles of erosion which 

 were laid down by G. K. Gilbert in his " Geology of 

 the Henry Mountains," and form the basis of modern 

 writings on erosion. He quotes Mr. Harker's paper 

 on the subaerial denudation of Skye {Geol. Mag., 

 1S99, p. 485) to show that in that district " the agents 

 of atmospheric degradation, erosion and transport- 

 ation, are at the present time almost wholly in- 

 operative," but ignores that writer's statement con- 

 cerning the great erosion of the district in Tertiary 

 times. Sir Henry, in fact, does not seem to have 

 recognised the importance of the " base-line of 

 erosion " as one of the controlling factors in the 

 sculpture of a district, and this vitiates many of the 

 arguments advanced in this section of the book. 



But there is much in this section that is sug- 

 gestive, especially the portions dealing with the effects 

 of earth-movement and fracture in the production of 

 valleys. In the " heroic age " of geology too much 

 influence was undoubtedly assigned to these effects 

 in accounting for valley-formation, and one cannot 

 but feel that with the swing of the pendulum, and 

 owing to the importance which geologists now attach, 

 and rightly attach, to agents of erosion, the influence 

 of movement accompanied by fracture, at any rate 

 as an indirect factor, has been unduly minimised. 



(3) The Capacity of Ice to Produce the Effects 

 Assigned to it. — In the two concluding chapters of 

 vol. i. and in the greater part of vol. ii., Sir Henry 

 is directly at issue with the modern geologists, for 

 in the majority of the phenomena which have been 

 appealed to in support of the operations of ice he 

 refuses to see any signs of ice-work. Notwithstand- 

 ing the ingenuity with which he argues, we cannot 

 see that he makes out a case. The Glacial period 

 has been established as the result of cumulative 

 evidence, and although there are many differences of 

 opinion on minor points, geologists are agreed as to 

 the occurrence of such a period in late Tertiary 

 times in consequence of what most of them consider 

 to be overwhelming evidence. 



Here we must insert a word concerning the 

 author's "old masters." In vol. i., p. 213, he takes 

 his stand " with the old masters, Hopkins and 

 Whewell, Conybeare, Sedgwick and JMurchison. 

 These men knew something more than geology; thev 

 were mathematicians and physicists as "well." 

 Again, on p. 460 he says :— " I do not hesitate myself 

 to confess, and to be proud of the confession, that I 



