34 



Anniversary Meeting. 



[Nov. 30, 



Murchison) are given in his Synopsis of the Classification of the British 

 Palaeozoic Rocks," 1855. It possesses the weight which must always be 

 recognized as appertaining to the authority of the geologist who, by his 

 own labours, first solved the great problem of the physical structure of the 

 district. 



There are other important memoirs of Professor Sedgwick's of which 

 time forbids more than a very passing notice. The memoir *' On the 

 Structure of large Mineral Masses," published in 1831, was the first, and 

 remains to this day the best descriptive paper which has yet appeared on 

 joints, planes of cleavage, nodular concretions, &c. 



Always attentive to the purpose of preparing a complete and general 

 classification of the Palaeozoic Strata, Professor Sedgwick at an early 

 period in his career printed a memoir " On the Physical Structure of the 

 Older Strata of Devon and Cornwall;" and another "On the Physical 

 Structure of the Serpentine District of the Lizard." Of later date are 

 several papers written by him, conjointly with Sir Roderick Murchison, 

 respecting the Devonian System. The principal of these, published in 

 1840, comprised the work of several previous years, and made known the 

 true nature of the Culm Beds of North Devon, as belonging to the Car- 

 boniferous series, and their position in a trough of the subjacent rocks, 

 which rocks, on account of their position and their organic contents, were 

 concluded to belong to the Devonian, or Old Red Sandstone period, a con- 

 clusion which was at first controverted, but was ultimately admitted. In 

 another memoir by the same authors in 1828, they conclude that the 

 coarse old red conglomerate along the north-western coast of Scotland and 

 in Caithness is of about the same age as the Old Red Sandstone of South 

 Wales and Herefordshire, and therefore of the Devonian period. They also 

 published in 1840 an account of their general observations on the Palaeo- 

 zoic Formations of Belgium and the Banks of the Rhine, the results of 

 which were considered to harmonize with those derived from other localities. 

 Finally, we may notice another joint memoir by these authors in 1830, 

 " On the Structure of the Eastern Alps," which, however, had no imme- 

 diate relation to the researches on the Palaeozoic formations. 



It will be observed that the memoirs which have been noticed are for 

 the most part pervaded by a certain unity of purpose. The investigations 

 were not on points of merely local interest, but were essential for the 

 elucidation of the geological history of our planet during those early 

 periods of which the records are most difficult to unfold. Few persons 

 perhaps can have an adequate idea of the difficulties he had to contend 

 with when he first entered North Wales as a geologist. Geologically 

 speaking, it was a terra incognita of which he undertook to read the 

 geological history before any one had deciphered the characters in which 

 it is written. Moreover, besides the indistinctness and complexity of the 

 stratification, and the obscurity which then prevailed as to the distinction 

 between planes of stratification and planes of cleavage, there was also the 



