SIR ARCHIBALD GEIKIE STRAHAN 595 



have been warmer had Geikie, true lover of nature as he was, shown 

 more cordiality in welcoming the elucidation of the truth. 



There remains, however, to his credit a great record of original 

 unchallenged work. He made a particular study of the composi- 

 tion and direction of transport of the Bowlder clay, and noted the 

 occurrence in it of stratified beds which he attributed to temporary 

 amelioration of climate. Originally an advocate of the iceberg 

 theory, he abandoned it in favor of Agassiz's views on ice sheets, 

 convinced by the work of his colleagues in Scotland and by what 

 he saw in northern Norwa3^ He recognized also among the Scot- 

 tish mountains the existence of moraines and glacierborne blocks 

 and the sites of glacial lakes as evidences of local glaciation during 

 the last phase of the Glacial Period. 



His great paper on the Old Red Sandstone of Western Europe, 

 as a piece of masterly description, takes high rank in geological 

 literature. His classification has in the main stood the test of time; 

 but, with characteristic reluctance to change a view to which he 

 had once committed himself, he persistently declined to remove the 

 Caithness Flagstones from the Lower Old Red Sandstone, though 

 they differed from that subdivision (as known in the Grampians) 

 both in their fishes and in their plants. The flagstones appear in 

 Geikie's map of Scotland as Lower Old Red, but on the geological 

 survey maps as Middle Old Red Sandstone. 



Volcanic episodes in the history of the earth had engaged Geikie's 

 attention from the first, and in 1860 he presented to the Royal 

 Society of Edinburgh a paper on " The Chronology of the Trap 

 Rocks of Scotland," in which for the first time an attempt was 

 made to arrange the volcanic periods evidenced in that country in 

 geological sequence. In dealing with this subject he was not satis- 

 fied till he had acquired the necessary experience by visiting the 

 volcanic regions of Auvergne, the Eifel, and Italy, and exploring 

 the great lava fields of western America. In Auvergne, especially, 

 the comparatively recent features displayed by volcanic energy 

 enabled him to picture the aspect of the ancient vents and lava flows 

 of the Firth of Forth. In the United States he found reason to 

 adopt Richthofen's view that the flat beds of basalt were due to 

 fissure eruptions, and applied this interpretation to the Tertiary 

 volcanic plateaus of the West Highlands. He summed up his ob- 

 servations and conclusions in his standard work on the Ancient 

 Volcanoes of Great Britain. 



Unlike Lyell, Geikie gained most of his experience by his own 

 observations in the field. In addition to the work done in his 

 leisure time, he was for some years a member of the field staff of 

 the geological survey, and after he had attained higher posts, 



