SIR HENRY H. HOWORTH, D.C.L., F.R.S., ON ICE OR WATER. 219 



matter and simnount obstacles. It need scarcely be observed 

 that to deal with these subjects otherwise than briefly, would 

 be impossible in an essay such as the present. The author 

 passes in review the various theories that have been propounded 

 to account for the Glacial Period. He examines the astro- 

 nomical theories of CroU and Sir li. Ball, and rejects them on 

 what seems to me sufficient grounds, notwithstanding the high 

 authority of the authors of the theories themselves. 



The author then goes on to deal with the views of Lyell, 

 Professor J. Geikie, Professor Prestwich, Chamberlin, and 

 others, and finally concludes with rejecting the generally 

 accepted evidences of a Glacial Epoch of Post-Tertiary age. I 

 h.o\)e I am not misrepresenting my friend, but the following are 

 his words : — 



"Are we obliged, or in fact are we justified, in invoking a 

 great Ice Age with its portentous ice- sheets ... in order 

 first to account for the stri;H5 on the polished rocks and on the 

 boulders, and secondly, for the manufacture of angular drift ? 

 To my mind the questions only need to be asked to answer 

 themselves." Again : " I have shown that the striae can be, 

 and ouGjht to be, assi2:ned to an entirelv different ao'ent than ice 

 if we are to follow inductive methods." (Preface, p. xliii.) 

 He then goes on to dispute the glacial origin of moraines, 

 referring them to the movement of stones and boulders over 

 the rock-surfaces by the action of concurrent and divergent 

 streams of stones, in many cases covered by drift. 



To this I will leply, that no one who has studied the 

 symmetrical arrangement of lines of grooving andstriation over 

 the glaciated surfaces of solid rocks in glacial districts could for 

 one moment suppose they had been produced by the rubbing of 

 stones and boulders promiscuously passing over the surface. 



Such statements as those quoted induce the doubt whether 

 so gifted an observer as the author has not allowed his better 

 judgment to be warped by a mistaken conception of the nature 

 of glacier ice. 



^Yhen the author comes to deal with the latest theory, 

 namely, that called by Mr. (}. K. Gilbert "The Epeirogenic 

 Theory," he evidently feels that he is treading on more dan- 

 gerous ground than when dealing with the views of the 

 before-named glacialists. In the first place this theory has 

 the support of a number of very distinguished adherents in 

 America — and to a less extent in this country— at the head 

 of which stands the venerated name of Professor J. Dana, 

 followed by those of Chamberlin, AVarren Upham, Professor 



