NATIONAL ACADEMY BIOGRAPHICAL MEMOIRS VOL. VIII 



study made there by Gilbert, whose famous report on the 

 Henry Mountains was thus brought forth. Powell's inatten- 

 tion to the complex structures of crystalline rocks was shown 

 by his usually giving the schists of the fundamental complex 

 at the bottom of the Colorado Canyon the popular name of 

 "granite." He attended relatively little to the conditions under 

 which ancient stratified deposits were accumulated, and prob- 

 ably on this account did not free himself from prepossessions 

 regarding the lacustrine origin of the freshwater Tertiaries, 

 and did not offer any explanation of the extraordinary cross- 

 bedding of the White Cliffs sandstone; but regarding larger 

 structures, he developed broad and bold generalizations that 

 followed immediately from field observation and geological 

 common sense, illumined by a free and lively imagination. He 

 evidently enjoyed the systematization of his results, and repeat- 

 edly reduced them to compact schematic form, from which 

 irrelevant details and unknown local names were withheld, 

 greatly to the advantage of his readers. His arguments were 

 usually stated in a simple manner, free from technicalities, and 

 his results were phrased in form for popular understanding. 

 He was fully persuaded that his opinions were correct, and not 

 infrequently stated them in the positive form of "inevitable 

 conclusions," as most of them still seem to be. They carried 

 conviction and are now accepted on nearly all points. 



Powell's unconscious style was simple and direct, as in the 

 extract given above describing the end of his passage through 

 the Colorado Canyon, or again in the famous paragraphs cited 

 below regarding the origin of the Green River canyon through 

 the Uinta Mountains. On account of the loss of his right arm 

 he had to employ an amanuensis, and therefore acquired the 

 time-saving capacity of dictating. His reports are astonish- 

 ingly free from the prolixity that too often accompanies this 

 method of composition; but they occasionally bear marks of 

 insufficient revision in the retention of impromptu inventions 

 like "outthinnings" and in the use of certain words that might 

 to advantage be replaced by others. It was perhaps not un- 

 natural that his phraseology sometimes became exalted, as in 

 the peroration of the Colorado River volume, where, as if re- 

 calling the excitement of the canyon journey, he wrote like an 



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