Reviews — Prof. HuWs Physical Geology of Ireland. 169 



limestone, the greatest limestone formation in the world, was built up mainly of the 

 coiled shells of a special group of Foraminifera, the Nummulites. Throughout this 

 inconceivably long lapse of time our island was more or less unsubmerged, its surface 

 being swept by subaerial waters, and its strata carried little by little into the adjoin- 

 ing ocean, to form perhaps some of the strata which were being piled up over the 

 ocean bed of the British area." ' 



The origin of the river-vallej's next claims attention. And here the views of 

 Jukes, Eamsay, and others are fully endorsed in accounting for the frequent 

 occurrence of such facts as that rivers cut through bold escarpments of hard rock, 

 which, at first sight, would appear certain to have barred the course of the streams. 

 It is thus argued that the course of the river Shannon, the largest river of Ireland 

 (where, for example, it cuts through the high ridges marked on either side by the 

 hills Slieve Bernagh and Slieve Arra, through which gorge it now flows, apparently 

 in preference to taking comparatively much lower ground, and an easier course, to 

 Galway Bay), is really due to the fact that when the river iirst took this channel, the 

 ground now forming these ridges of mountains was in reality somewhat lower than 

 the ground to the north of it, now part of the plains. And the river, having once 

 commenced cutting out its channel, has never since abandoned that course, but has 

 gone on gradually lowering its valley, till the wide gorge, through which it now foams 

 in its rapids and falls, resulted. Reasoning of a similar kind is applied to the cases 

 of the Blackwater, the Lee, etc. ; but here Prof. Hull, most justly as we think, brings 

 in also the consideration of other physical causes, and argues that in such cases, where 

 not only do the rivers cut across ridges of harder rocks, but, to do so, divert their 

 course nearly at right angles to their general direction, there must have been some 

 disturbance at or close to the point of divergence ; and in the two cases noticed he 

 appeals to the existence of lines of fault at these localities, which have naturally had 

 a tendency to divert the water-course. We are glad to see this open acknowledg- 

 ment of the influence of such forces, which have been, we think, too much ignored 

 of late years. 



Passing over the notice of some " old di'ied-up river-valleys," as the author calls 

 some gorges, which have obviously been originally cut out by running water, but 

 which now have only trifling little streams trickling through them, or are dry, we 

 come to the Lakes of Ireland. These are divided into three classes — (1) Lakes of 

 Mechanical origin— (2) Lakes of Glacial origin— (3) Lakes resulting from Chemical 

 solution. These lakes in Ireland are very numerous and extensive, covering a very 

 large area of the country. Pre-eminent among them is Lough Neagh, the largest 

 lake in the British Isles. This Mr. Hardman^ has shown to be of Post-Miocene age, 

 perhaps Pre-Pliocene, and Mr. Hull adopts the views of this valuable paper. They 



1 We regret that we are compelled to think that Prof. Hull has very seriously 

 injured the effect of this telling' paragraph by the concluding sentences. It is so 

 seldom that we find any attempt at what might be called foi-ced oratory or over- 

 strained sentiments in Mr. Hull's matter-of-fact writings, that any departure from 

 good taste in such a direction makes the stronger impression. The danger of using 

 terms and expressions derived from and only applicable to intellectual beings, and 

 their rational acts, in explanation of inorganic forces, has often been insisted on, 

 and has here also proved to be the origin of the pseudo-scientific and false analysis 

 of the writer. It may be perfectly true that part of the material removed from the 

 surface of Ireland was thrown down in the British area, and may so far have contri- 

 buted to the future mineral wealth of England. But when he speaks of Ireland 

 " stripping herself to clothe her sister," " and to supply materials for protecting from 

 atmospheric waste her vast stores of Coal, upon which her greatness and prosperity 

 now so largely depends ; " and even goes on to exclaim '■' this debt ought never to he 

 forgotten " — the writer only excites the smile of geologists and the wondering stare 



of others. We should not wonder, to carry out the idea further, if some of the 

 modern Home Rulers would threaten to bring an action to recover compensation for 

 the loss incurred by their country (countless ages before man existed at all) by this 

 reckless sacrifice to England ; while on the other hand we have little doubt that some 

 of those who are now harassed and vexed by the obstructiveness of modern patriots 

 would be glad to see a little continuance of the former generosity on the part of 

 Ireland towards her poor sister, in these sadly degenerate days ! ! We cannot too 

 strongly reprobate such mischievous and false attempts at sentimentality in scientific 

 questions. 



2 Geol. Mag. Vol. III. Dec. II. p. 556; Journ. Roy. Geol. Soc. Irel. vol. iv. 

 p. 170. 



