ADDRESS 



BY 



ANDEEW CROI^IBIE RAMSAY, Esq, 



LL.D., F R.S., V.P.G.S., Director- General of the Geological Survey of 

 the United Kingdom, and of the Museum of Practical Geologj, 



PRESIDENT. 



On the Recukrence of Certain Phenomena in Geological Time. 



In this address I propose to consider the recurrence of the same kind of 

 incidents throughout all geological time, as exhibited in the various for- 

 mations and groups of formations that now form the known parts of the 

 external crust of the earth. This kind of investigation has for many 

 years forced itself on my attention, and the method I adopt has not here- 

 tofore been attempted in all its branches. In older times, Hutton and 

 Playfair, in a broad and general manner, clearly pointed the way to the 

 doctrine of uniformity of action and results, throughout all known geo- 

 logical epochs down to the present day ; but after a time, like the prophets 

 of old, they obtained but slight attention, and were almost forgotten, and 

 the wilder cosmical theories of Werner more generally ruled the opinions 

 of the geologists of the time. Later still, Lyell followed in the steps of 

 Playfair, with all the advantages that the discoveries of William Smith 

 afforded, and aided by the labours of that band of distinguished geologists, 

 Sedgwick, Buckland, Mantel!, De la Beche, Murchison, and others, all 

 of whom some of us knew. Notwithstanding this new light, even now 

 there still lingers the relics of the belief (which some of these geologists 

 also maintained), that the physical phenomena which produced the older 

 strata were not only different in kind, bat also in degree from those which 

 now rule the external world. Oceans, the waters of which attained a high 

 temperature, attended the formation of the immitive crystalline rocks. 

 Volcanic eruptions, with which those of modei'n times are comparatively 

 insignificant, the sudden upheaval of great mountain chains, the far more 

 rapid decomposition and degradation of rocks, and, as a consequence, the 

 more rapid deposition of strata formed from their waste — all these were 

 assumed as certainties, and still linger in some parts of the world among 

 living geologists of deservedly high reputation. The chief object of this 

 1880. B 



