152 



NATURE 



[December 17, 189: 



young friend to Sir Henry De la Beche, the Director- 

 General of the Geological Survey, that a post was at once 

 found for him on the staff of the Survey, and before many 

 days Ramsay was at work at Tenby. He joined the 

 service in the spring of 1841, immediately after the publi- 

 cation of the little volume on Arran, which embodied the 

 fruits of his labours in previous years. From that time 

 onward his life was spent continuously in the work of the 

 Survey until he retired at the end of 1881. So capable a 

 lieutenant did he prove himself to the chief of the staff, 

 that after only four years he was appointed Local 

 Director for Great Britain. 



From the first Ramsay showed that, with habits of 

 patient observation and cautious induction, he combined 

 a faculty for bold and broad generalization. His remark- 

 able paper on the denudation of South Wales, published 

 in 1846, was one of the earliest essays in which the 

 amount and effects of denudation were worked out from 

 detailed surveys of the geological structure of the ground. 

 He then struck the key-note which may be heard through 

 nearly all his subsequent contributions to scientific litera- 

 ture. He was one of the earliest observers to realize that 

 the existing topography of the land has a long and inter- 

 esting history, much of which may still be deciphered by 

 the use of geological investigation. 



The name of A. C. Ramsay will ever be honourably 

 associated with the story of the gradual working out of 

 the records of the Ice Age. Following up the results 

 obtained by Agassiz, Buckland, Darwin, and others in 

 this country, he threw himself with all his ardour into 

 the study of the glaciation of Wales, tracing the limits 

 of the glaciers of that region, and extending his expe- 

 perience by frequent excursions among the Swiss Alps. 

 His scattered papers in scientific journals undoubtedly 

 did much to stimulate general interest in the history of 

 the Glacial Period, and to create a special and volumin- 

 ous literature of this subject. His views differed much 

 from those of some of the older geologists of the day, 

 and led to some active controversy. Especially did 

 opposition arise when, after studying long and carefully 

 the erosive action of land-ice, he came to the conclusion 

 that certain lake-basins in various parts of the world had 

 been scooped out by ice. Murchison, Lyell, and others 

 of less fame, entered the lists against him ; but he had a 

 considerable following among the younger geologists. 

 And this controversy still fitfully continues. 



In connection with his glacial work, mention should 

 be made of his bold endeavour to prove that ice-action 

 had been in operation more than once in the geological 

 past. His paper on the Permian breccias of England 

 called attention to the evidence of transport of fragments 

 of rock from Wales, and to the resemblance between 

 these fragments and those in glacial moraines and 

 boulder-clay. He subsequently detected what he thought 

 to be similar traces of ice-carried materials in the Old 

 Red Sandstone ; and in one of the last papers which he 

 wrote he gathered together the various pieces of evidence 

 in favour of a long succession of Glacial periods in the 

 geological past. 



Two of the most suggestive essays he ever wrote were 

 his well-known Presidential Addresses to the Geological 

 Society in 1863 and 1864, in which he worked out, from 

 his wide practical acquaintance with the stratified forma- 

 tions of Britain, the idea of breaks in the succession of 

 organic remains in the geological record. To the geo- 

 logist and the palaeontologist these papers marked a 

 distinct epoch in the advance of geological inquiry ; 

 while to the biologist concerned with the history of 

 the evolution of organized existence on this planet they 

 were full of luminous thought. 



By far the largest part of Sir Andrew's contributions to 

 geological literature is to be found in the maps, sections, 

 and memoirs of the Geological Survey. The mapping of 

 the volcanic districts of North Wales, in which he took 



NO. 1155. VOL. 45] 



the leading part, will ever remain the best monument of 

 his skill as a field-geologist. His exhaustive memoir on 

 that region has long since taken its place as one of the 

 standard works of reference in our geological literature. 



In his later years he seems to have taken pleasure in 

 reverting to some of the inquiries which he started in an 

 early part of his career. He returned with renewed zest 

 to the study of the history of topographical features, dis- 

 coursed as to how Anglesey became an island, and 

 traced out the story of the River Dee. In successive 

 editions of the work on the "Physical Geography and 

 Geology of Great Britain," which at first was given as 

 six lectures to an audience of working men, he worked 

 out in greater fulness the chief stages through which the 

 surface of this country seemed to him to have passed 

 before it acquired its present features. 



Of the value of his scientific labours full recognition 

 was made by his contemporaries. He was elected Pre- 

 sident of the Geological Society in 1862, President of the 

 Geological Section of the British Association in 1866 

 and again in 1881, and President of the Association itself 

 in 1880, when the meeting was held at Swansea. He 

 received the Wollaston Medal of the Geological Society, 

 the Neill Medal of the Royal Society of Edinburgh, and 

 a Royal Medal from the Royal Society. He was chosen 

 into the honorary list of many learned Societies at home 

 and abroad. On the death of Sir Roderick Murchison 

 in 1 87 1, he was appointed Director-General of the Geo- 

 logical Survey. At the end of 1881 he resigned this 

 office, was knighted for his distinguished services, and 

 soon thereafter went to reside at Beaumaris, where his 

 strength has gradually given way, until he died on the 

 evening of the 9th inst. 



There was in Sir Andrew Ramsay such simplicity and 

 frankness that men of the most diverse natures were 

 attracted to him, and as they came to know him more 

 intimately the gaiety and kind-heartedness of his dis- 

 position attached them to him in the closest friendship. 

 Fond of literature, and glad to relieve the pressure of his 

 scientific work by excursions into the literary field, he had 

 acquired a range of knowledge and of taste which gave 

 a special interest to his conversation. Now and then he 

 found time to write an article for the Saturday Review in 

 which this literary side of his nature would find scope for 

 its exercise. But the daily grind of the official treadmill 

 left him all too little time for such diversions. His death 

 removes from our midst one of the foremost geologists of 

 our day, and from the friends who knew him in his prime, 

 a large-hearted, lovable man, whose memory they will 

 cherish till they too pass away. A. G. 



ON VAN DER WAALS'S ISOTHERMAL 

 EQUATION.-*- 



ONE of the objections raised against this equation by 

 Prof Tait in Nature, vol. xliv. pp. 546 and 627, 

 brings clearly to light the importance of the question 

 whether the finite size of the particles should be accounted 

 for by an equation of the form — 



p^(v - b) = l^mu"-, (I) 



where pi represents the internal pressure, equal to the 

 sum of the external pression/, and the molecular pressure 

 ajv^, and b some multiple of the total volume b■^ of the 

 particles ; or if this equation must rather have the form — 



p^v = i2»««2(^i +~^ (2) 



' Prof. Korteweg's paper and accompanying letter are of date November 

 4, but owing to an accidental delay they did not reach me until after the 

 appearance of my last communication (Nature, November 26, p. 80). Other- 

 wise 1 should, of course, havp made reference to them. It will be seen that 

 Prof. Korteweg draws attention to the form of the virial equation applicable 

 in one dimension. Ravleigh. 



December 2. 



