OBITUARY NOTICES OF FELLOWS DECEASED. 



Sir William Edmond Logan was born at Montreal on the 20th 

 of: April, 1798. His education was commenced at Montreal, where he 

 remained until, in 1814, he was sent to the High School of Edinburgh. In 

 1818 he was taken into the house of his uncle, Mr. Hart Logan, a 

 merchant in London ; but, in 1829, after a short visit to Canada, he 

 accepted the management of a copper-smelting work at Swansea. 



His attention was soon attracted to the geology of the district, 

 especially to the Coal-measures of the great South- Wales Coal-field, 

 of the western half of which he constructed, entirely at his own 

 cost, a geological map, on the scale of 1 inch to a mile, with hori- 

 zontal sections on a scale of 6 inches to a mile, and vertical sections on a 

 scale of 40 feet to an inch. While engaged in this work he dis- 

 covered the true relation of the clays charged with Stigmaries under- 

 lying each bed of coal, and proved them to be the soil on which the 

 plants, afterwards turned into coal, had grown. In 1840 he com- 

 municated this discovery to the Geological Society. This work was so 

 completely and accurately executed, that when Mr. De la Beche began 

 the Government Geological Survey of that area he adopted the whole of 

 it, which Mr. Logan generously handed over to him for the benefit of the 

 Survey ; and the sections became in a measure the models on which all the 

 Coal-measure sections of the Survey were afterwards constructed. Having 

 given up his connexion with the copper-works, Mr. Logan was appointed by 

 the Colonial Government, in 1843, to organize and carry on a Geological 

 Survey of Canada, his native country, with which his family had long been 

 connected ; and this work, by his own labours and the help of his assistants, 

 he carried on as Director of the Survey till the year 1869, when, in con- 

 sequence of increasing years, he resigned the appointment, and Mr. 

 Selwyn, now one of the Fellows of this Society, was appointed as his 

 successor. The admirable geological work that he did in Canada, and the 

 beautiful geological maps and sections thereby produced, are well known 

 to the geological world ; for he not only unravelled and laid down on 

 maps all the complicated Devonian, Silurian, and Huronian rocks of a 

 vast region, but he first discovered underneath all these the true strati- 

 graphical relations of the Laurentian series, which had previously been 

 vaguely termed granites. He thus showed that they consisted of two great 

 divisions, the Lower Laurentian gneiss and the Upper Laurentian gneiss, 

 which lies quite unconformably on the lower series, both of them con- 

 taining thick interstratified beds of crystalline limestone. 



vol. xxiy. rt 



