Dugald Bell — The " Great Submergence.''* 67 



,;.j'"0 In an article by Mr. Mellard Reade on tlie "Present Aspects 

 of Glacial Geology," which appeared in the December number of 

 this Magazine, there is the following note : — 



' ' Mr. Dugald Bell, previous to the discoveries of Mr. Smith in Ayrshire, thre^v 

 such doubts upon the recorded instances of the occurrence of shells in the Drift of the 

 South of Scotland that the stock example of Chapelhall, near Airdrie, which was 

 supposed to prove a submergence of about 500 feet, was omitted in the last edition 

 of Dr. James Geikie's well-known ' Ice Age.' A committee with Mr. Dugald 

 Bell as a member re-examined the locality, with a result entirely negative. This is 

 only another instance of the futility of negative evidence, for, as we see, not long 

 afterwards evidence of the most conclusive sort of the presence of sea-shells in 

 natural sections open to the world were found in Ayrshire up to double the height." 

 (Geol. Mag., December, 1896, p. 549.) 



There are several points here. 



1. The doubts expressed regarding Chapelhall — referring to the 

 narrowness of the basis of evidence on which it rested, and the 

 probability of the clay not being in situ — belonged to that case in 

 itself, and are wholly unaiFected by anything discovered elsewhere, 

 whether before or since. The same doubts should be expressed in 

 the same terms still, were the case still to open. 



2. It was not the expression of these doubts, however well 

 founded they might appear to him, which induced Professor Geikie 

 to suppress this "stock instance" in the last edition of his work; it 

 was the corroboration or substantiation of them by the Committee of 

 the British Association failing to find the clay in the position indicated 

 by all the accounts of it, or in the neighbourhood. Dr. Geikie then 

 justly suppressed it, as unsupported by evidence ; the only fault 

 that can be found with him being that he did not state any reason 

 for doing so. 



3. Though in one sense the result of the Committee's investigation 

 was negative, in so far that the clay was not found, in another it 

 was quite positive : the clay was not where it was reported to be. 

 It was said to be in the excavation for a certain well, 14 ft. from the 

 surface, as a bed 19 ft. long by 5 ft. broad, and 2 ft. thick in the 

 centre. The Keport of the Committee showed that no such bed of 

 clay could have escaped their search, and that in other respects the 

 statements so long repeated did not tally with the facts (see British 

 Association Eeports, 1894:). It was evident that " some one had 

 blundered," or had been misled. Why this result should be called 

 " futile " because something else — a boulder-clay at the same or 

 a greater elevation — has been discovered elsewhere, I cannot 

 imagine. Every case must be decided on its own evidence. Chapel- 

 hall has collapsed. The value of the Ayrshire sections as proofs of 

 submergence has yet to be determined. My own opinion, frankly, 

 is that it is nil ; but I keep my mind open till the evidence be more 

 fully wrought out, and meantime deprecate hasty and sweeping 

 statements on the subject. 



4. In another part of his paper Mr. Mellard Reade speaks 

 of " a great glacier proceeding from the Atlantic, crossing Kintyre 

 and the Firth of Clyde, and working 25 miles inland" into 

 Ayrshire, as if that were the idea involved in the theory of those 



