R. Murchison, A. Sedgwick, H. Delabeche 315 



they are developed. Sedgwick 's influence on the modern 

 school of geologists is difficult to overestimate. 



At the close of the Silurian Period there was an irregular 

 sinking of the land. The old surface was worn down and the 

 material for new lands built up from the products of the 

 waste. England was in the region of most constantly recurring 

 movements ; and it so happened that during the period that 

 now supervened the British Isles formed part of the margin 

 of Eurasia, in which there were more limited hydrographical 

 areas. In one place corals grew in bright clear water, while, 

 not far off, lagoons and swamps favoured the growth of a rich 

 semi-tropical vegetation, with a fresh or brackish water fauna 

 in which fish abounded. The beds with this later facies 

 received the name of Old Red Sandstone. Local geologists 

 were led to study the exceptionally rich deposits which 

 occurred near their homes, and thus the fishes of the Old 

 Red Sandstone in Scotland arrested the attention of Hugh 

 Miller, one of whose fascinating books was a description of 

 this formation. 



Sir Henry Delabeche (1796-1855) was attracted to the 

 tongue of land which runs out to meet the Atlantic on our 

 south-west coast. He recognized that mapping, mapping, 

 mapping, was the chief essential for the understanding and 

 recording of the geological structure of a country. He long 

 worked single handed at the district, and published treatises 

 and memoirs which are still classic works. But his crowning 

 achievement was the establishment of the Government 

 Geological Survey, which has developed into a great school 

 of geological research, and proved the model on which all 

 similar institutions have been organized. 



John Phillips (1800-1874), the Oxford Professor of 

 Geology, was born on the great rim of rocks which hold the 

 South Wales Coal field as in a basin. From its swelling hills 

 and crags it was called the Mountain Limestone, a name by 

 which it is still commonly known. Phillips was drawn away to 

 Yorkshire, where he soon found himself on the very same 

 Carboniferous rocks, on which, as well as on the secondary 

 rocks which succeeded them, he wrote admirable treatises. 



The nomenclature followed the hammers of these leaders 

 of research, but now, alas, students cannot avail themselves 



