660 EEPORT— 1886. 



fragments of Arclisean schists and gneiss, with the distinctive characters of those 

 rocks impressed upon theiu prior to their deposition in their present habitat, are 

 pointed to as facts confirmatory of the above theory. 



10. On the Influence of Axial Rotation of the Earth on the Interior of its 

 Crust. By Johx Gunn, F.G.S. 



The autlior stated that the effect produced by axial rotation upon the exterior 

 surface of the earth in its primitive heated condition was well known, but the effect 

 upon the interior crust had been overlooked ; that it is incumbent upon him to 

 prove that the condition of the earth beneath the exterior crust is such as to render 

 axial rotation not merely a probable, but an indisputable agent of pressure upon 

 the surrounding crust. 



He proves that the crust is pliable, and that fluids exist beneath it at a depth 

 of a few miles, not exceeding twenty, by the opinions of the most eminent scientists, 

 and especially of Professor Prestwich, whom he quotes freely from, and refers to 

 his able treatise, published in the * Proceedings of the Royal Society,' on the Agency 

 of "Water in Volcanic Eruptions, with Observations on the Thickness of the Earth's 

 Crust. 



The author states that an abundance of facts prove the existence of such a fluid 

 as would be subject to axial rotation, which, being 7iil at the centre of the globe, 

 increases in power and velocity as it approaches the surface. 



The question arises as to whether the power of rotation, which he humbly sub- 

 mits must exist, is not modified, and perhaps overcome, bj' centripetal gravitation. 

 He refers, as a proof of the reality of its agency, to its coincidence with seismology. 

 Dim-nal rotation answers to the mildest form of seismology observed at Japan ; 

 annual and more extended rotations answer to the intermittent rumbling and 

 shocks of earthquakes throughout the world ; precessional perihelionic and the 

 most extended revolutions allowed by astronomers answer to the changes induced 

 by the inclination of the axis of the earth. 



The author alluded to the tendency to revolve noticed by Mr. White and 

 others in some buildings at Colchester during the shock lately experienced there 

 as indicative of rotating power ; also to the sequence and succession of earthquakes 

 observed by Professor Sedgwick as travelling generally from east to west, and 

 expressed his extreme diffidence in his own opinions, which nevertheless he was 

 desirous to publish, as possibly there might be some reality in the effect he attri- 

 buted to the axial rotation of the earth, notwithstanding it had been overlooked by 

 writers on the subject. 



Mr. Gunn is of opinion that the force of internal rotation, combined with that 

 of earthquakes, has a bearing upon the ingenious theory of Dr. I. Evans, that the 

 shiftily of portions of the earth's crust may be due to it ; also that many of the 

 contortions of the Drift seen at Cromer, in Norfolk, and in the Eifel district, and 

 at Corfu and many other places, are due to the same cause. 



Geology Sub-Section. 



1. Notes on some of the Problems now being investigated hy the Officers of 

 the Geological S^irvey in the North of Ireland, chiefly in Co. Donegal. 

 By Professor E. Hull, LL.B., F.B.8. 



The author stated that the investigations of the Survey were confined to the 

 counties of Antrim and Donegal ; and, restricting his observations to the latter, he 

 said the chief problem was whether or not there were two great series of meta- 

 morphic rocks unconformable to each other, the older referable to the Archaean 

 age, the newer to the Lower Silurian. 



Some reference was made to the great faults and foldings of these beds, which 



