i6 W. J. MCGEE 



of it — it is to be noted that there are no great chemical labora- 

 tories in this country, no institutions comparable with the ^ 

 astronomical observatories and geological surveys and natural^ 

 history museums which have given prestige to American 

 science. 



Half a century ago geology was on the plane to which it 

 had been raised by Lyell's law of uniformism — a law which 

 contributed much to the cult proclaimed by Tyndall and 

 Huxley; and this plane was effectively expanded by the efforts 

 of several American geologists. With singular perspicacity 

 and pertinacity, Hall and his associates developed an American 

 scheme of rock classification (the New York system), which 

 was expoimded and crystallized by Dana, and has since served 

 as the model for the continent ; and in an address delivered in 

 1857, though not printed for a generation. Hall foreshadowed 

 the laws of mountain making and other distinctive principles 

 of modern geology. Thus, within the first decade of the half 

 century the earth science of America had come to stand well 

 abreast of that of Europe. Checked by the social shock of 

 the early sixties, research rested; but toward the end of the 

 decade it began anew, and as exploration pushed into the Cor- 

 dilleran region, where the stone book lies open, it sprang for- 

 ward with unprecedented vigor. Hayden, King, and Powell 

 in the territories, and Whitney in California, were the princi- 

 pal pioneers in the field, while Powell, Gilbert, and Button 

 led in lifting the science to the third plane in its development; 

 for, through recognition of the "baselevel of erosion," they laid 

 the foundation for the new geology, which reads earth history 

 from the forms of hill and vale as well as from the formations 

 and fossils of past ages. Within a dozen years the principles 

 have been applied and extended in the coast plains of the 

 southeastern states, where they have made both land forms 

 and uncomformities eloquent records of continent growth; 

 while Davis, of Harvard, has successfully employed the same 

 principles in reading from topographic maps the later chapters 

 of earth history. 



Meantime, the glacial theory, imported by Agassiz from 

 Switzerland, rooted kindly in American soil, and soon bore 

 fruit; Chamberlain, Shaler, Salisbury, and a score of others 



