SKETCH OF SIR WILLIAM E. LOGAN, LL.D., F.G.S. 693 



the coal-seams were formed, and devoted a large share of his scanty- 

 leisure to making a geological map of the district. His drawings were 

 offered to Sir Henry de la Beche, when the latter began his govern- 

 ment survey in that region, and Sir Henry gladly availed himself of 

 them, giving due credit to Logan. While he remained in its vicinity, 

 Loo-an did much for the museum of the Royal Institution of South 

 Wales, and held the positions of Honorary Secretary and Curator of 

 the Geological Department. He presented to it valuable collections 

 of minerals and metallurgical products, laboratory apparatus, draw- 

 ings, and a collection of Canadian birds. Logan rapidly became 'known 

 among British geologists, and in 1837 was elected a Fellow of the 

 Geological Society. The next year his uncle died, and Logan gave 

 up his position in the Morriston copper-works. 



The problem of the formation of coal-strata, which had engaged 

 Logan's attention, was at this time far from settled, one party firmly 

 maintaining that the carbonaceous matter had collected as drift-wood 

 collects ; another, that the seams were deposited like peat in the 

 swamps. "In these circumstances," says his biographer, Professor 

 Harrington, " Logan had the sagacity to observe and turn to account 

 a fact which has settled forever the question of the origin of coal, in 

 favor of the theory of growth in situ. Under eighty or more coal- 

 seams, which occur in the Welsh coal-field, the miners had observed 

 the invariable presence of a bed of more or less tenacious and bleached 

 clay, which they called the ' under-clay ' of the coal, and which was 

 often of practical importance as affording facilities for under-cutting 

 the coal. The constancy of this fact Logan confirmed by his own ob- 

 servations, and added to it the further and important discovery that in 

 all these under-clays there occurred abundance of remains of the pecul- 

 iar plant known as Stigmaria, in such circumstances as to show that 

 the plant was in situ, and not drifted. In February, 1840, Mr. Logan 

 communicated his results to the Geological Society of London, in a 

 paper entitled " On the Characters of the Beds of Clay immediately 

 below the Coal-Seams of South Wales." 



In his letters from Wales to his brother James, Logan had repeat- 

 edly asked for specimens of the Canada minerals, and had expressed 

 the wish to examine for himself the rocks of his native region. Ac- 

 cordingly, in the summer of 1840, he left England for Canada. 

 During his year's visit to America, he made geological studies in the 

 neighborhood of Montreal, in Maine, and, just before his return, 

 visited the coal-fields of Pennsylvania and of Nova Scotia. The re- 

 sults of two of his investigations he embodied in a paper entitled " On 

 the Packing of Ice in the St. Lawrence, and on a Land-Slide in the 

 Valley of the Maskinonge," which he read before the Geological 

 Society of London in June, 1842. From the parts of this paper 

 quoted by Thomas Keefer in his " Report on the Bridging of the St. 

 Lawrence," George Stephenson is said to have obtained useful hints in 



