I 



I 



TRANSACTIONS OF SECTION C. M4Si 



Tinderlymg source of igneous material. Intrusion must then take place during 



interstitial movement, fluxion structures will he produced in the more or less 

 difl'erentiated igneous magmas, the sediments will he injected and impregnated 

 with igneous material, and thermo-metamorphism will he produced on a regional 

 scale. The origin of gneisses and schists, in my opinion, is to be sought for in a 

 combination of the thermal and dynamic agencies which may be reasonably 

 supposed to operate in the deeper zones of the earth's crust. If this view be 

 correct, it is not improbable that we may have crystalline schists and gneisses of 

 post-Silurian age in the north-west of Europe formed during the Caledonian fold- 

 ing, others in Central Europe of post-Devonian age due to the Hercynian folding, 

 and yet others in Southern Europe of post-Cretaceous age produced in connection 

 with the Alpine folding.^ But if the existence of such schists should ultimately 

 be established it will still probably remain true that rocks of this character are in 

 most cases of pre-Cambrian age. May not this be due to the fact, suggested by a 

 consideration of the biological evidence, that the time covered by our fossiliferous 

 records is but a small fraction of that during which the present physical conditions 

 have remained practically constant ? 



The good old British ship ' Uniformity,' built by Hutton and refitted by Lyell, 

 has won so many glorious victories in the past, and appears still to be in such 

 excellent fighting trim, that I see no reason why she should haul down her colours 

 either to ' Catastrophe ' or ' Evolution.' Instead, therefore, of acceding to the 

 request to ' hurry up ' we make a demand for more time. The early stages of the 

 planet's history may form a legitimate subject for the speculations of mathematical 

 physicists, but there seems good reason to believe that they lie beyond the ken of 

 those geologists who concern themselves only with the records of the rocks. 



In this address I have ventured to express my views on certain disputed 

 theoretical questions, and I must not conclude without a word of caution. The 

 fact is, I attach very little importance to my own opinions, at least on doubtful 

 questions connected with the origin of the crystalline schists ; but, as you have 

 done me the honour to accept me as your President, I thought you might like to 

 know my present attitude of mind towards some of the unsolved problems of 

 geology. There is still room for legitimate difierence of opinion on many of the 

 subjects to which I have referred. Meanwhile, we cannot do better than remember 

 the words with which one of our great living masters recently concluded an article 

 on a controversial subject : ' Let us continue our work and remain friends.' 



' Some geologists maintain that this is the case, others deny it. See H. Reusch, 

 ' Die fossilienfiihrenden krystallinischen Schiefer von Bergen in Norwegen,' Leipzig, 

 1883 ; J. Lehmann, ' Ueber die Entstehung der altkrystallinischen Schiefergesteine, 

 mit besonderer Bezngnahme auf des sachsische Granulitgebirge, Erzgebirge, Fich- 

 telgebirge, und bairisch-bohmische Grenzgebirge,' Bonn, 1884 ; T. G. Bonney, 

 several papers on the Alps, and especially ' On the Crystalline Schists and their 

 Relation to the Mesozoic Rocks of the Lepontine Alps,' Quart. Jourii. Geol. Soc, 

 vol. xlvi. (1890), p. 188 ; A. Heim, contribution to the discussion on the last paper; 

 C. W. Giimbel, ' Geognostische Beschreibung des K. Bayern ' and ' Grundziige der 

 Geologie,' Kassel, 1888-1892. 



Although it is convenient to speak of the three types of folding which have so 

 largely influenced the structure of the European continent as if each belonged to a 

 definite period, it is important to remember that this is not strictly true. The 

 movements were prolonged ; they probably crept slowly over the surface of the 

 lithosphere, as did the zones of sedimentation, so that those of the same type are 

 not in all places strictly contemporaneous. 



The following Papers and Reports were read : — 



1 . Nutes on the Water-hearing Capacity of the New Bed Sandstone of 

 Nottingham. By Professor Edward Hull, LL.B., F.B.S., F.G.S. 



About half a century ago, before the problems of sanitation were generally 

 understood, the town of Nottingham was placed in a most unfavourable position as 



