n6 GEOLOGY 



the development of the science. The foundations of the 

 relatively modern science of physiographical geology had 

 already been laid in the eighteenth century, through 

 studies by DEMAREST in the valleys of the Auvergne of 

 Central France, studies which have been ably extended 

 in our own day by DE LA NOE, DE MARGERIE, and DE 

 MARTONNE. The brilliant DE BEAUMONT, in collabo- 

 ration with DUFRENOY, gave a great impetus to geological 

 mapping, at the time in its infancy, by the preparation 

 of che geological map of France begun in 1825. 



Earthquake study necessarily began with the collec- 

 tion of facts connected with the great earthquakes of the 

 past. These data, as assembled by Alexis PERREY of 

 Dijon between the years 1841 and 1874, constitute a 

 great reservoir from which all later investigations have 

 drawn their supplies. Today the greatest systematizer 

 in seismology and its leading authority is a Frenchman, 

 Count DE MONTESSUS DE BALLORE. Within the field of 

 oceanography, studies of the most fundamental character 

 dealing with the deposits upon the sea bottom have been 

 carried out by THOULET. In the field of structural 

 geology, it is today generally recognized that the key 

 to the solution of that most complex problem, the struct- 

 ure of the Alps, was supplied by BERTRAND, upon the 

 basis of studies made in the north of France. His other 

 investigations covered a very wide field and were of 

 prime importance. Experiments to reproduce rock 

 structures in the laboratory have had their origin and 

 development very largely in France; the leading part (if 

 we except the most recent work by refined methods) 

 having been taken by DAUBREE. A reservoir of data 

 upon existing glaciers is the "Materiaux pour Petude 

 des glaciers," by DoLLrus-AussET, which appeared in 

 thirteen volumes between 1864 and 1870. The most 

 noteworthy of general treatises upon geology, in the 



