262 POPULAR SCIENCE MONTHLY. 



theory, and for many years during his surveys paid no attention to it. 

 His first recorded mention of it was a diary entry in March, 1S45, 

 recording a "jolly night at the Geological; Buckland's glaciers 

 smashed " — the reference being to a paper read by A. F. Mackintosh 

 on the supposed evidences of the former existence of glaciers in Xorth 

 Wales, controverting conclusions previously published by Buckland. 

 It vi^as during the survey of the Snowdon region, where " he 

 achieved his chief geological triumph " in unfolding the compli- 

 cated history of former volcanic activity contained therein, that he 

 began to regard the subject of glacial action seriously, and this not 

 till he had been at work there several months. His first reference 

 to the subject occurs in the record of a visit by Robert Chambers to 

 him at Llanberis, in August, 1848, when Chambers and he are men- 

 tioned as having gone " out on a glacial excursion up the Pass." A 

 walk across the hills the next day revealed " splendid examples of 

 glacial action." The search for such examples was the special object 

 of Chambers's visit. By the 15th of N^ovember, however, he seems 

 to have recognized everywhere the peculiar smoothing and polishing 

 produced by moving ice, and he described the summit of a certain 

 precipice as being, " as usual, well grooved with glacial undulations." 

 His first public profession of belief in the former existence of 

 glaciers in Wales was on the occasion of an address to the Geological 

 Society in December, 1849, on the Geological Phenomena that have 

 produced or modified the Scenery of l^orth Wales, in which glacial 

 action was presented prominently. The lecturer at the same time 

 gave new and original proofs of the former presence of glaciers, 

 " particularly instancing cases where mountain lakes were still held 

 back by ridges of terminal moraine, and where large blocks of rock 

 were perched on ice-worn crags." After this his notebooks contain 

 frequent references to glaciers. Thus he went on, meeting frequent 

 new illustrations of the history of the Glacial period, with his eyes 

 now opened to the existence and significance of the facts whereby 

 he was " led to perceive the meaning of many scattered surface 

 features in South Wales to which, at the time he was surveying in 

 that region, he had paid little heed." On the 26th of March, 1851, 

 he communicated his first paper on glacial phenomena to the Geo- 

 logical Society, On the Sequence of Events during the Pleistocene 

 Period as evinced by the Superficial Accumulations and Surface- 

 markings of [N'orth Wales. Having withheld this paper from pub- 

 lication a year for more mature study, he issued it in 1852 under the 

 title of On the Superficial Accumulations and Surface-markings of 

 ISTorth Wales." The chief point insisted upon in it was the preva- 

 lence of two glaciations — one widespread and prior to the deposition 

 of the drift, the other local in the valleys and posterior to it. 



