242 



NATURE 



[July 13, 189: 



felt, nnd as Mr. Swiiibume points out, the attitude of the 

 Royal Society is of prime importance. Many would 

 regret if the Society to which the " Principia " was com- 

 municated ceased to publish physical work, and indeed 

 if we know anything of the feelings of English Physicists, 

 we do not think that such a catastrophe is probable. On 

 the other hand, it is impossible not to recognise the fact 

 that the Royal Society is an obstacle to the realisation 

 of a satisfactory scheme for the publication of English 

 physical papers. 



The Physical Society was founded because at that time 

 the Royal Society offered no facilities for the experi- 

 mental illustration of communications made to it. The 

 meetings of both the elder and the younger society are 

 fully occupied with the work now undertaken, in spite 

 of the fact that the discussions at the meetings of the 

 Royal Society are short. 



If to-morrow all English physicists were to agree to 

 send all their work to the Royal Society there would not 

 be time to discuss it, and many of the papers thus 

 offered, though worthy of publication, would be regarded 

 as not of the type which the Society affects. Yet if there 

 is to be organisation, if order is to succeed chaos, it can 

 only be either by a friendly struggle between the Royal 

 and the Physical Societies, which would not be likely 

 to lead to any definite result at present, or by still 

 more friendly co-operation between them, by which all 

 that is desired might be attained in a few months. That 

 going forward or standing still are ahke difficult is un- 

 deniable. It is obvious that the conditions which apply 

 to physics apply to other branches of natural know, 

 ledge. We shall bs glad if those most closely inter- 

 ested will try to smooth the way by discussion in our 

 columns. 



THE CAUSES OF GLACIAL PHE!VO.\fENA. 



The Glacial Nightmare and the Flood : a Second Appeal 

 to Common Sense from the ■ Extravagance of some 

 Recent Geology. By Sir Henry H. Howorth, K.C.I.E., 

 M.P., F.R.S,, F.G.S., &c., &c. (London : Sampson 

 Low, Marston and Co., 1893.) 



IT is not uncaramon to find that Ttxzn who have devoted 

 much time and careful research to the elucidation of 

 complex phenomena have experienced all the phases of 

 thought through which a succession of previous observers 

 have passed in bringing the subject to its then present 

 stage. This is more usual in certain classes of inquiry 

 than in others, and in such it is clearly helpful to dwell 

 upon the history of the development of opinion upon the 

 question. It is giving, as it were, the embryology of an 

 idea in order to enable the reader to understand belter 

 the adult form. In the volumes before us Sir Henry 

 Howorth has rendered this good service to students 

 of glacial phenomena. 



The title of the book is unfortunate and may prejudice 

 many against what is really a scientific work of great 

 value. 



Sir Henry first gives a sketch of the views of the earlier 

 writers who referred all the phenomena in question to the 

 action of water ; then he explains liow by degrees the 

 agency of icebergs was called in ; how it was next con- 

 sidered that larger glaciers would account for most of the 

 NO. 1237, VOL. 48] 



facts ; and how, after that, it was supposed that they were 

 to be explained only on the hypothesis of great ice-sheets 

 extending south from either pole, even to the tropics, 

 according to some. 



These ice-sheets must, of course, be accounted for by 

 exceptional agencies, such as secularly-recurring astro- 

 nomical combinations, in connection with which the author 

 discusses the obvious inference that there must have been 

 similar combinations and similar results in previous ages. 

 He then devotes almost the whole of another volume 

 to the various incidental theories which have grown up 

 round the theory of circumpolar glaciation, or are 

 necessary to it, and, finally, admitting a moderate ex- 

 tension of glaciers, he sums up in favour of stronger and 

 more widely extended marine action than has of late been 

 generally admitted. 



As we read we cannot but learn to admire the shrewd 

 observation of the older geologists, though the true 

 explanation of the phenomena had not yet been put 

 forward. We see how the obvious suggestion that great 

 rushes of water would account for it all, set Von Bucli and 

 Hopkins to calculate what depth and velocity of water 

 would be required to obtain force necessary to transport 

 the blocks perched on the hills ; and if there were difficult 

 cases which made some of the " Champions of Water," 

 such as Mierotto, De Luc, and Hall call in the aid of ice- 

 bergs, still there was the fact that a great deal of the drift 

 appeared to be sorted by water, and that, in great floods, 

 boulders several feet in diameter have been hurried along 

 the rocky bed of a stream with a noise like thunder ; that 

 large stones are often tossed by the storm waves to the 

 top of precipices on our western rock-bound coast, as may 

 be seen on a smaller scale where single stones are thrown 

 on to a pier or promenade, though the sea-wall may be 

 almost vertical. The gravel carried by a spate ove- the 

 meadows is just like that found in the Esgairs, and is 

 thrown up on either side of the torrent in long ridges. 

 There is no doubt that a great deal of what is included in 

 the drift, especially in Germany, is just like what is 

 carried by flood water. It would not be comfortable to 

 feel that the great old heroes of geology advocated views 

 impossible in physics and unsupported by observation. 

 Whether better explanations may in many cases now be 

 offered is another question. 



When it was once admitted that the glaciers were 

 formerly much more extensive, and the drift round moun- 

 tain regions was referred to their agency, it is easy to see 

 how the impossibility of accounting for the occurrence of 

 glaciers in North Germany, where what was thought to be 

 similar drift was widely spread, led to speculation as to 

 the possible extension of ice-sheets from high latitudes 

 all over north-western Europe and north-eastern Ame- 

 rica, and the views of Bernhardi and Schimper, which 

 involved an ice-sheet coextensive with the distribution of 

 the drift began to be received with favour. 



After this was given up as the direct cause, it was still 

 held that its indirect effects would be very potent in pro- 

 ducing extremes of climate alternately in the north and 

 south hemispheres. The question now naturally arose 

 whether there were any recurring glacial conditions in 

 past times, and evidence of such action was seen in 

 rounded surfaces and striated stones from various ancient 

 rocks. 



