170 Barrell — Growth of Knoivledge of Earth Structure. 



envelopes and tending toward a hydrostatic equilibrium. 

 In this latter field of investigation, America, since the 

 initial paper by Dutton, has taken the lead. 



Conclusion on Contributions of America to Theories of Orogeny. 



The sciences arose in Europe, but those which treated 

 of the earth were still in their infancy when transplanted 

 to America. The first comprehensive ideas on the nature 

 of mountain structures arose in Great Britain and 

 France. These ideas served as a guide and stimulus to 

 observation in the recognition of deformations in the 

 strata of the Appalachian system. Since 1840, however, 

 America has ceased to be a pupil in this field of research 

 but has joined as an equal with the two older countries. 

 New ideas have been contributed, new and striking illus- 

 trations cited first by the scientists of one nation, next by 

 those of another. The composite mass of knowledge has 

 grown as a common possession. Nevertheless, a review 

 of the progress since 1840 as measured by the contribu- 

 tion of new ideas shows on the whole America at least 

 equal to its intellectual rivals, and at certain times 

 actually the leader. This is true of the science of geol- 

 ogy as a whole and also of the subdivision of orogeny. 



Thus far no mention has been made of German geolo- 

 gists, with the exception of Suess, an Austrian. German 

 geology is voluminous and the names of many well-known 

 geologists could be cited. But this article has sought 

 to trace the origin and growth of fundamental ideas. 

 The Germans have been assiduous observers of detail; 

 preeminent as systematizers and classifiers, seldom orig- 

 inators. Even petrology, which might be regarded as 

 their especial field, was transplanted from Great Britain. 

 In the science of mountains they have followed in their 

 fundamental ideas especially the French. 



Turning to the mediums of publication through which 

 this progress of knowledge in earth structures has been 

 recorded, the American Journal of Science stands fore- 

 most as the only continuous record for the whole century 

 in American literature, fulfilling for this country what the 

 Quarterly Journal of the Geological Society has done for 

 Great Britain since 1845, and the Bulletin de la Societe 

 Geologique for France since 1830. 



