MR MILNE ON THE MID-LOTHIAN AND EAST-LOTHIAN COAL-FIELDS. 335 



to credit so stupendous a change. At the same time it should be observed, that 

 this particular revolution would form only one of a series of revolutions indicated 

 by the successive deposits existing in the district ; — and that however unprepared 

 we may have been, some years ago, for crediting the recent occurrence of ex- 

 tensive changes, we have now far less scruples in giving our assent to the evi- 

 dence of it, when we consider, that at this very moment there are whole conti- 

 nents gradually sinking, and others gradually rising from beneath the waters of 

 the ocean. 



In conclusion, and with reference to the geology of the district generally, 

 I may observe, that it is impossible for any one who is familiar with the outward 

 features of it not to perceive, that even they bear, in a considerable degree, the 

 visible impress of the subterranean changes and convulsions which I have, in 

 the foregoing memoir, attempted to trace. I have stated, for example, that there 

 are two coal basins, formed by the position into which the stratified rocks have 

 been thrown. If this were the case, we should expect to find, that the lowest 

 parts of the whole district would be along the centre or trough of these basins. 

 This is found to be the fact. The trough of the principal basin commences at 

 Fisherrow, and runs up by Dalkeith, Roslin, and Pennicuick, to Carlops. Now, 

 these are known to be the points of lowest level in that part of the country ; and 

 accordingly, it is by these places that the principal river there, viz. the Esk, is 

 found to flow. The other basin is, in like manner, for a considerable distance 

 watered by the Tyne. It is hardly necessary to add, that it is owing to the same 

 cause, that the deepest and most extensive superficial deposits of sand and clay, 

 which overspread the district, occur in the central parts of the Esk basin. 



I might advert to many other proofs, — as, for example, the existence of the 

 Roman Camp hiU, and the high ridge which runs to Tranent, — in illustration of 

 the proposition that the present configuration of the country has been greatly af- 

 fected by even the most ancient geological changes. But I pass on, to notice the 

 effect which more recent geological changes have also had in this respect. It is 

 not possible to go to any part of the district, without witnessing deep and in- 

 delible traces of that violent rush of waters, which bared all the western faces of 

 our hills, — left on their eastern flanks a heap of rubbish, including boulders many 

 tons in weight, — and scooped out hollows where the current was contracted and 

 confined. I do not refer now merely to excavations discovered in mining opera- 

 tions : — I refer to others visible to the naked eye and the most casual observer, 

 and which have ever since remained filled with large bodies of water. That the 

 hollows now occupied by Duddingston Loch and Lochend, — and the low ground 

 on the north and south sides of the Castle Rock of Edinburgh, till lately the re- 

 ceptacles of considerable accumulations of water, — ^that these localities bear the 



