October i i, 1900] 



NATURE 



587 



GFAILOGY AT THE BRITISH ASSOCIATION. 

 'X'HE geologists had a busy and profitable week at Bradford, 

 ■'■ and an air of business-like application to work pervaded 

 their meetings from first to last. The programme ought to 

 have been long enough to satisfy even the most devoted adherent 

 of Section C ; but apparently there was no sense of satiety, 

 since on two or three occasions when it was proposed from the 

 platform that communications should be taken as read, there were 

 protests raised by the audience, who seemed determined to carry 

 matters through with true North-country thoroughness, and 

 wished to hear everything. And indeed it may be said that there 

 was scarcely a paper in the long list which did not contain scien- 

 tific matter well worthy of discussion, though it must be acknow- 

 ledged that in several instances the matter was not particularly 

 novel. It was only by the strict enforcement of a time-limit upon 

 readers of papers and debaters, and by sessions on the mornings 

 of Saturday and Wednesday as well as lengthy sittings on the 

 other days of the meeting, that the business was got through. 

 Under these circumstances it was inevitable that some excellent 

 papers scarcely received full justice ; but the discussions were 

 nevertheless unusually full of vigour, and what was still better, 

 entirely lacking in acrimony. 



The fine weather of the week, which was so favourable to the 

 short afternoon excursions, now a recognised and highly valued 

 feature in the affairs of the section, had probably much effect in 

 fostering the prevailing good-humour, while the personality of 

 the president was a strong influence in the same direction, 

 especially in the discussions. 



To particularise all the papers within the space-limits of this 

 article is mipossible, and we can only attempt to convey a 

 general impression of the proceedings, with brief reference to the 

 points of main interest. 



On Thursday, as a fitting appendix to the wide-reaching 

 generalisations of the president's address, already printed in 

 these pages, we had a series of papers from Prof. J. Joly 

 dealing with geological problems from the standpoint of the 

 physicist. In one of these, " On the geological age of the 

 earth, as indicated by the sodium contents of the sea," Prof. 

 Joly reiterated the calculations and conclusions which have 

 recently attracted so much attention in geological circles ; in 

 another, "On the inner mechanism of marine sedimentation," 

 he showed the chemical and physical reasons for the rapid pre- 

 cipitation of fine solid matter brought down in suspension by 

 rivers into the sea ; a third of kindred character gave the result 

 of " experiments on denudation by solution in fresh and salt 

 water"; and a fourth, which was especially attractive to the 

 petrologists ana mineralogists, dealt with " the vi.scous softening 

 of rock-forming minerals at temperatures below their normal 

 melting point," showing how certain minerals could be observed 

 to attain a plastic state some time before actually melting. 



At the same meeting Prof. W. B. Scott, of Princeton, gave a 

 highly interesting account, with lantern illustrations, of recent 

 explorations in Patagonia conducted under the direction of Mr. 

 J. B. Hatcher. Besides correcting previous errors as to the age 

 of the deposits, the records and the rich collections of fossils 

 obtained by this expedition have sufficed to prove a close con- 

 nection between Australia, New Zealand and South America in 

 Miocene times, and in several other respects to modify pro- 

 foundly our previous ideas of South American geology, and 

 incidentally to show how much geologists have still to learn in 

 every way from the unexplored tracts of the earth's surface. 



On Friday, Prof. J. Milne led off in his usual happy vein 

 with an account of the year's work of the Seismological Com- 

 mittee, and was followed by Mr. Clement Reid, who showed 

 how well-chosen, from geological reasons, was the site for 

 instrumental observation, by the same committee, of the Upway 

 disturbance. There then followed a series of papers and reports 

 on the Mountain-limestone district of north-west Yorkshire and 

 its underground waters, Mr. S. W. Cuttriss giving an account 

 of the adventurous exploration of the deep pot-holes and caves 

 of this district by himself and other members of the Yorkshire 

 Ramblers' Club, and the Rev. W. Lower Carter and Mr. A. R. 

 Dwerryhouse presenting the results obtained by a local com- 

 mittee and by a committee of the Association in the investiga- 

 tion of the subterranean drainage of the limestone. Being well- 

 illustrated by lantern slides, these papers besides attaining th^ir 

 moie direct purpose served to give the strangers an idea of the 

 general characteristics of the district which was afterwards to be 

 visited by geological excursion parties. By the use of suitable 



chemical reagents the course of the water from its disappearance 

 in " sink holes " of the limestone to its reappearance in springs 

 at lower levels has in several instances been traced ; it has been 

 shown that the main direction of underground flow is along the 

 ma.ster-joints of the limestone ; and a subterranean watershed of 

 which there is no mdication at the surface has been traced for 

 some distance. These experiments are to be continued, and a 

 grant of 50/. was made by the Association towards this end. 



Among other papers taken on Tuesday were two by Mr. E. 

 Greenly, giving further results of his painstaking researches in 

 Anglesey. In one of these he dealt with the ancient surfaces or 

 peneplains which he thinks can be recognised in North Wales ; 

 the older plain he is inclined to regard as of sub-Carbon- 

 iferous age, and the later as Mesozoic, possibly Cretaceous. 

 There was an interesting discussion on this paper, in the course 

 of which Mr. Greenly acknowledged that his views were only 

 tentatively held, and might require modification. Dr. G. Abbott 

 then gave an account of his investigation of the concretionary 

 .structures of the Magnesian Limestone of Durham, illustrating 

 his subject by lantern-slides and the exhibition of a large series 

 of specimens 



Saturday's business began with a paper by the President, " On 

 a concealed coalfield beneath the London basin," in which it 

 was urged, on data not altogether convincing, that if a boring 

 were made in the vicinity of Enfield Lock on the Lea, it might 

 be expected to reach Coal-measures. As a speaker in the discus- 

 sion remarked, such a boring would no doubt reveal something 

 interesting, but whether Coal-measures was another matter. 

 Then followed a paper by Mr. R. H Tiddeman " On the forma- 

 tion of reef-knolls," which was practically a criticism of Mr. J. E. 

 Marr's views as to the development of these structures in the 

 Mountain-limestone of West Yorkshire and Lancashire by earth- 

 movement, and a reiteration of the author's earlier contention 

 that they were originally formed as mounds on a slowly sinking 

 sea-bottom. As Mr. Marr was present to champion his own 

 cause, the paper was followed by a brisk but friendly discussion, 

 which was prolonged on a later day in the open air, when some 

 of the mounds at Cracoe near Skipton were visited by a few 

 members interested in the subject. No definite conclusion was 

 reached, but the necessity for further investigation was made 

 evident, and it was suggested that the truth might lie in a com- 

 bination of the two hypotheses. 



Another paper taken on Saturday was that . of Mr. W. 

 Gibson, " On rapid changes in the thickness and character of the 

 Coal-measures of North Staffordshire," in which it was shown that 

 the areas of maximum and minimum deposit in these rocks cor- 

 respond respectively with a syncline and anticline, thereby sug- 

 gesting that local areas of deposit were being marked out by 

 contemporaneous movements of elevation and depression, thus 

 fulfilling in North Staffordshire the conditions characteristic of 

 the Carboniferous rocks of the Midlands generally. These re- 

 sults have an important practical application, inasmuch as the 

 unexplored coal-field to the westward, which occupies a syncline, 

 may thereby be expected to exhibit an increase in the thick- 

 ness of the strata. At the same meeting, Rev. J. F. Blake 

 brought forward some revolutionary suggestions in regard to the 

 registration of type-specimens, among other proposals urging 

 that a new class of " adopted " types should be recognised and 

 registered where the original types were missing or inadequate, 

 and that the type should consist of a single specimen. As Prof. 

 Blake has now been elected a member of the committee of the 

 Association at present in existence for furthering the registration 

 of type-specimens, we may hope that his interest in the matter 

 may bear fruit. 



On Monday there was a crowded audience to hear the joint 

 discussion with the botanists on the conditions during the growth 

 of the forests of the Coal-measures. The discussion was opened 

 by Mr. R. Kidston, who gave a succinct account of the plant-life 

 of the period, illustrated by fine lantern slides. Mr. A. Strahan 

 then dealt with the physical conditions, and gave his adherence 

 to the "drift " as opposed to the " growth-in-place" theory of 

 the origin of coal-seams, summing up the normal sequence of 

 events in the formation of a seam as follows : — First, the out- 

 spreading of sand and gravel with drifted plant remains ; followed 

 by shale as the currents lost velocity ; and then a growth of 

 presumably aquatic vegetation in extremely shallow water into 

 which wind-borne vegetable dust and floating vegetable matter 

 was carried ; after which renewed subsidence brought in the 

 sand and mud-laden currents again and the whole process was re- 

 commenced. Mr. A. C. Seward followed with a clear statement 



NO. 1615, VOL. 62] 



