Sir A. Geikie—Age of the Earth. 469 



or was slowly elevated by one prolonged and continuous movement. 

 But they might furnish us with suggestive information as to the 

 rate at which upheaval or depression of the terrestrial crust is now 

 going on. 



The vexed questions of the origin of Raised Beaches and Sunk 

 Forests might in like manner be elucidated by well-devised measure- 

 mtents. It is astonishing upon what loose and unreliable evidence 

 the elevation or depression of coast-lines has often been asserted. 

 On shores where proofs of a recent change of level are observable it 

 would not be difficult to establish by accurate observation whether 

 any such movements are taking place now, and, if they are, to 

 determine their rate. The old attempts of this kiud along the coasts 

 of Scandinavia might be resumed with far more precision and on 

 a much more extended scale. Methods of instrumental research 

 have been vastly improved since the days of Celsius and Linnaeus. 

 Mere eye-observations would not supply sufficiently accurate 

 results. When the datum-line has been determined with rigorous 

 accuracy, the minutest changes of level, such as would be wholly 

 inappreciable to the senses, might be detected and recorded. If sucli 

 a system of watch were maintained along coasts where there is 

 reason to believe that some rise or fall of land is taking place, 

 it would be possible to follow the progress of the movement and to 

 determine its rate. 



But I must not dwell longer on examples of the advantages which 

 geology would gain from a far more general and systematic adoption 

 of methods of experiment and measurement in elucidation of the 

 problems of the science. I have referred to a few of those which 

 have a more special bearing on the question of geological time, but 

 it is obvious that the same methods might be extended into almost 

 every branch of geological dynamics. While we gladly and gratefully 

 recognize the large amount of admirable work that has already been 

 done by the adoption of these practical methods, from the time of 

 Hall, the founder of experimental geology, down to our own day, we 

 cannot but feel that our very appreciation of the gain which the 

 science has thus derived increases the desire to see the practice still 

 further multiplied and extended. I am confident that it is in this 

 direction more than in any other that the next great advances 

 of geology are to be anticipated. 



While much may be done by individual students, it is less to their 

 single efforts than to the combined investigations of many fellow- 

 workers that I look most hopefully for the accumulation of data 

 towards the determination of the present rate of geological changes. 

 I would, therefore, commend this subject to the geologists of this and 

 other countries as one in which individual, national, and international 

 co-operation might well be enlisted. We already possess an 

 institution which seems well adapted to undertake and control 

 an enterprise of the kind suggested. The International Geological 

 Congress, which brings together our associates from all parts of the 

 globe, would confer a lasting benefit; on the science if it could 

 organize a system of combined observation in any single one of the 



