ANNIVEESAP.Y ADDRESS OF THE PRESIDENT. 55 



demonstrates, by a sketch of the geology of the Diirness-Erriboll 

 region, that the ordinary principles of stratigraphy would lead obser- 

 vers in two adjacent , districts to absolutely contradictory results 

 viz. that in the Durness area, the Sutherland (or Newer) Gneiss 

 series is demonstrably newer than the (fossiliferous) Paloeozoic series, 

 and in the Erriboll area is demonstrably older. In the other papers, 

 published in the May and August numbers (the series was, I believe, 

 left incomplete through his illness), he proceeds to apply to the 

 Scotch Highlands the principles of mountain stratigraphy enunciated 

 by Rogers, Heim, Ealtzer, and others, and shows how, in the process 

 of folding, inversions and overthrust-faults may be produced on a 

 gigantic scale, and appearances of conformable succession and even 

 of bedding be simulated, which are nevertheless wholly deceptive. 



The matter, then, before the end of the year 1883, in the summer of 

 which a detachment from the Geological Survey took the field in 

 Sutherland, stood thus : two or three of those whom I may call the 

 minor contributors to this controversy, had pointed out serious 

 mistakes and unsuspected difiiculties, and had expressed, in effect, 

 this opinion, that very clear evidence would be needed before we could 

 accept the dominant rocks of the Highlands as of Lower Silurian age. 

 Dr. Hicks had shown that unless lithological similarity in neighbour- 

 ing districts be of no value, a very large portion of the rocks in the 

 mountain region of South Eoss-shire and Inverness must be much older 

 than the Torridon Sandstone, and that there was evidence of faulting 

 and folding on a gigantic scale. Dr. Callaway had shown the same 

 for the western part of Sutherlandshire, and had proved the ex- 

 istence of unsuspected inversions and overthrusts ; while Professor 

 Lapworth had demonstrated the Murchisonian hypothesis to be 

 self-contradictory in a region regarded by its upholders as typical, and 

 had shown us that the difficulties, anomalies, and deceptive appear- 

 ances are such as are usual phenomena in mountain-making on a grand 

 scale*. 



I have dwelt but little upon the discordances or the errors of the 

 observers whose work I have noticed Perfect concordance among 

 reformers is not to be expected ; and men who are honestly struggling 

 towards the light cannot hope to attain at one bound to the 

 complete truth. There is always a danger lest the fascination of a 

 new discovery should lead us too far. Men of science, being 

 human, are apt, like lovers, to exaggerate the perfections and be a 

 little blind to the faults of the object of their choice. Even now, 

 great as has been the flood of light thrown upon the question by 

 the writings of the Director General and his officers, I am sure 

 that they would be the last to indulge in the illusion that they have 

 solved every mystery or may not have to correct some details. It 



* I have omitted in the above brief sketch several papers of minor impor- 

 tance "which have appeared in the ' Greological Magazine ' and other publications, 

 and a series of papers by Prof. Heddle in the ' Mineralogical Magazine ;' the 

 latter, because, notwithstanding their value as contributions to the mineralogy 

 of the Highlands, I do not think they help us much in the elucidation of the 

 above-named problem. 



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