XXX\ail PEOCEEDINGS OP THE GEOLOGICAL SOCIETY. 



ing of the British Association, or in our own rooms, or in general 

 conversation, will long recollect the facility of expression and the 

 occasional bursts of eloquence which would animate his treatment 

 of favourite topics. 



The great work of his life was the final Report on the Geology 

 of Pennsylvania, a magnificent quarto filled with carefully col- 

 lected details and illustrations of that great region, which em- 

 braces a great part of the most important mineral wealth of the 

 United States. For the purpose of more readily completing his 

 maps and plates Mr. Eogers betook himseK to Edinburgh, and 

 there established an intimate acquaintance with many members of 

 the Scottish literary community. In 1857 he was invited to accept 

 the Professorship of Natural History and Geology at Glasgow, 

 which honourable post he retained until his death in May last. 



For several years before his fatal attack, Prof. Eogers had been 

 in dehcate health, but had nevertheless made several journeys to 

 America, and had continued at intervals his scientific and literary 

 pursuits. Whilst employed in his great survey he had contributed 

 to the Proceedings of this Society a paper entitled " Some facts in 

 the Geology of the Central and West Portions of Forth America." 

 A long series of Memoirs and Reports, published in the American 

 scientific journals, have placed his name among the highest of the 

 numerous excellent geologists who refiect credit on the United 

 States. In 1856 he delivered a lecture at the Royal Institution, 

 containing an admirable summary of the geology and physical geo- 

 graphy of Korth America. In this address he dwelt specially on 

 those great features which he had elaborated in his survey, the 

 disturbance of the Palaeozoic rocks of the Appalachian chain — " a 

 stupendous undulation, or wave-like pulsation, the strata being 

 elevated into permanent anticlinal and synclinal flexures, remark- 

 able for their wave-like parallelism, and for their steady declining 

 gradation of curvature, when they are compared in any east and 

 west section across the corrugated zone." To the westward of the 

 Appalachian chain, where this structure is conspicuous, he pointed 

 out that " the crust- waves flatten out, recede from each other, and 

 vanish into general horizontality." Coupled with these leading 

 features, he remarked that the total thickness of the Coal-measures 

 steadily diminishes from some 3000 feet thick in Pennsylvania to 

 1500 feet in the Illinois basin, and to not more than 1000 feet in 

 the basins of Ohio and Missouri ; and, similarly, the number of 

 workable seams of coal dwindles from 25 on the Schuylkill to pro- 

 bably 7 in Indiana and Illinois, and but 3 or 4 in Iowa and 

 Missouri. And when we add to this the clearly established facts 

 of the increasing amount of sea-deposits simultaneously vrith the 

 decrease of land-derived materials eastward, and the diminishing 

 effects of metamorphism in the same direction, from the fully bitu- 

 minous coals of the Western States to the hard anthracites of the 

 most disturbed region, it must be conceded that Professor Rogers con- 

 tributed a noble quota to the unravelling of some of the grandest 

 phenomena which geologists have been called upon to investigate. 



