666 EDITORIAL 



origin as comprising, first, discussion of the conditions of formation 

 of sediments; second, comparison of the areal and volumetric 

 importance of the several kinds of deposits now forming; third, 

 consideration of the probable changes in relative importance which 

 may have occurred in the past; and fourth, presentation of de- 

 tailed distinctions by which the several deposits may be recog- 

 nized, with a view to separating and interpreting them in terms 

 of geography and climate. 



It may be said that this is the sound scientific method of pro- 

 ceeding from facts to interpretation. It is also sound engineering. 

 It builds permanent structures. By means of it, in the paper 

 referred to and by others in which he applied the distinguishing 

 criteria of sedimentation to specific examples, Barrell made an 

 important and essentially original contribution to geology in that 

 he forced the recognition of continental, fluviatile, and eolian 

 sediments among stratified rocks which had been previously 

 regarded as of marine origin exclusively. He thus revolutionized 

 the criteria of paleogeography and paleoclimatology. 



Paleoclimatology is a field to which Barrell unlocked the gate, 

 if indeed he may not be said to have discovered it. His article on 

 relations between climate and terrestrial deposits traces the 

 complex variations of temperature and rainfall and their effects 

 upon sediments with such keen analytic power, such wealth of 

 illustration, and such logic as to lay firmly the foundations of 

 interpretation of terrestrial stratigraphy in terms of climate. 



Among the great problems of the past thirty years in geology 

 and geodesy there is none more congenial to a mind like Barrell's 

 than that of the strength of the earth's crust. His investigation 

 of the subject illustrates the conscientious thoroughness with 

 which he did his work. He was so serious, so earnest in inves- 

 tigation, that he could not leave any aspect of a subject untouched. 

 His presentation is therefore an exhaustive review, analysis, and 

 critique of the contributions previously made, together with a 

 statement of the deductions which he found reasonable. He 

 attacked the complexities of the subject, not only as a geologist 

 and engineer, but also as a mathematician. He did not hesitate 

 to enter the lists against those who arm themselves with higher 

 mathematics and who seem invulnerable to attack by geologists 



