ACADEMY OP SCIENCES] SCIENTIFIC METHOD 147 



A 

 were applied. Let him show in what way the failure of one hypothesis aided in the invention of another. Let 

 him set forth not only the tests which verify his final hypothesis, but the considerations which leave a residuum 

 of doubt as to its validity. And finally let him indicate, if he can, the line or lines of research that promise to 

 throw more light. 



But it is recognized that an essay thus prepared will not have a great number of readers: 



The majority of those who examine an essay seek only to learn its conclusions and have tune for nothing more. 

 For their use there should be appended or prefaced a concise summary of results. 



There can be no question that the author of a scientific essay should consciously scrutinize 

 not only the matter that he treats but also his method of treating it; but it may be doubted 

 whether all authors of essays which even in their own opinion involve new principles should 

 publish the many detours on their routes of mental travel in such detail as is here recommended. 

 It is to be feared that scientific journals would be thereby too largely filled with futilities by 

 workers of a vainglorious type, and that others, indeed the very ones whose mental routes their 

 colleagues would be glad to know, would hesitate to adopt a method of writing that might seem 

 to them like exclaiming: "Look at me; let me show you how to do it!" Scientific diffidence 

 of that sort is responsible for much of the obscurity from which the history of science suffers and 

 by reason of which the biography of scientific men is often too largely a narrative of their physi- 

 cal performances rather than of their intellectual characteristics. Even in Gilbert's own case, 

 the mental methods' of his earlier progress are lost, because he then did not adopt the self- 

 revelation that he later advised. 



But in his fuller maturity when he wrote the "Inculcation" essay in his forty-second year, he 

 practiced his preaching and told in much detail how he had gradually worked out an explanation 

 for the warping of the Bonneville shore lines, this being the particular " example " heselectedfor 

 analysis. It had long been tacitly postulated that the shore fines were level; but when it was 

 found that a certain member of the group, the continuity of which had been traced by direct 

 observation, was higher in the southern than in the northern part of the former lake area, the 

 tacit postulate was overthrown and "an hypothesis immediately took its place," the hypothesis 

 of "unexplained undulation." It was later discovered that a fault ran along the base of the 

 Wasatch Range and it was then recognized that f aid ting might modify undulation; but it was 

 eventually learned, as quantitive records were increased, that deformation by faulting was much 

 smaller than that by undulation ; thus the latter became the chief factor, and search was made for 

 its cause. As a guide in this search the measures of deformation were charted, and it was thus 

 found that the figure of deformation was "a low, broad dome, having its crest over the main 

 body of Lake Bonneville." Therefore the additional hypothesis was introduced that "the de- 

 formation stands in some necessary or causal relation to the lake and its disappearance" ; and as 

 the lake was disposed of by evaporation, it was concluded that "the change in the lake was the 

 cause, and the change in the land was the effect." The manner in which the disappearance of 

 the lake might lead to the deformation of the shore lines was next taken up, and three explan- 

 atory hypotheses were introduced, but at this point the discussion becomes so detailed that it 

 can not be advisedly followed further here. 



FIRST VIEWS ON ISOSTAST 



Faithful to his principles, Gilbert concluded his address with a brief indication of the un- 

 certainty attending the provisional conclusion that he reached, and with some suggestions con- 

 cerning important lines for further research. The most promising of the latter would be "an 

 exhaustive hypsometric survey of the Bonneville shore line, including all bays and islands," for 

 this might "render possible an evaluation of the rigidity of the earth's crust" — a subject which he 

 treated some years later in greater detail — and the behavior of the earth's crust must throw light 

 upon the condition of the earth's interior, "one of the great problems of our generation." Those 

 who have approached this problem — 



from the geologic side have based a broad induction on the structural phenomena of the visible portion of the 

 earth's crust, and have reached the conclusion that the nucleus is mobile. Those who have approached it from 

 the physical and astronomic side have reached the conclusion that the nucleus is rigid. Here seems an oppor- 



