INTERPRETATION OF LAND FORMS 149 



It is surprising to note the delays, the backward steps, 

 and the duplication of effort resulting from lack of 

 familiarity with the work of the pioneers. Sabine says 

 in 1864 : 73 



"It often happens, not unnaturally, that those who are most 

 occupied with the questions of the day in an advancing science 

 retain but an imperfect recollection of the obligations due 

 to those who laid the first foundations of our subsequent 

 knowledge. ' ' 



The product of intellectual effort appears to be con- 

 ditioned by time of planting and character of soil as well 

 as by quantity of seed. For example: Erosion by 

 rivers was as clearly shown by Desmarest as by Dana and 

 Newberry 50 years later. Criteria for the recognition of 

 ancient fluviatile deposits were established by James 

 Deane in 1847 in a study of the Connecticut Valley 

 Triassic. Agassiz's proof that ice is an essential factor 

 in the formation of till is substantially a duplication of 

 Dobson's observations (1826). 



The volumes of the Journal with their very large num- 

 ber of articles and reviews dealing with geology show 

 that the interpretation of land forms as products of 

 subaerial erosion began in France and French Switzer- 

 land during the later part of the eighteenth century as a 

 phase of the intellectual emancipation following the Rev- 

 olution. Scotland and England assumed the leadership 

 for the first half of the nineteenth century, and the first 

 100 volumes of the Journal show the profound influence 

 of English and French teaching. In America, independ- 

 ent thinking, early exercised by the few, became general 

 with the establishment of the Federal survey, the increase 

 in university departments, geological societies and peri- 

 odicals, and has given to Americans the responsibilities 

 of teachers. 



Bibliography. 



(In the following list "this Journal" refers to the American Journal 

 of Science.) 



1 Wilson, J. W., Bursting of lakes through mountains, this Journal, 3, 

 253, 1821. 



2 Whitney, J. D., Progress of the Geological Survey of California, this 

 Journal, 38, 263-264, 1864. 



8 Playfair, John, Illustrations of the Huttonian theory of the earth, Edin- 

 burgh, 1802. 



