IOWA ACADEMY OF SCIENCES. 20 



physicist have gradually assumed greater complexity, and 

 his mechanical aids have become more and more intricate. 

 But the same elementary directness of method, and the 

 same ingenuit}^ in discerning exactly what must be in- 

 cluded in a line of inquiry, and what may be safely left 

 out, have also distinguished the later physicists from Davy 

 to Rowland. 



The simple and elementary nature of physical research 

 has no doubt also given character to the mental habits of 

 the phj^sicist. Concentration on such simple, definite 

 problems as he deals with has tended to make him pene- 

 trating and critical in judging of the value of the evidence 

 brought to light in research. He has set up for himself 

 standards and adopted criteria as exacting and vigorous as 

 those of the mathematician. 



If I have been just and fair in drawing this outline 

 sketch of the physicist, his field of work, his habits, meth- 

 ods and standards, it should represent the scientist in 

 whatever department we look for him. It is indeed of the 

 highest importance in any scientific inquiry that the inves- 

 tigator knows the exact scope of his problem, and is dis- 

 criminating and unsparing in weighing the evidence that 

 his search has found, in just the way here made out to be 

 necessary for the physicist. 



It seems to have been inevitable, however, that physics 

 should have been the first of the material sciences to 

 develop the modern methods of research and to provide 

 modern aids. It was in the search for truth in regard to 

 physical laws especially that men first broke away from 

 the time honored servitude to the authority of the old 

 philosophers, and added experiment to observation and 

 mathematics, as the means of this search, and thus pointed 

 the way for modern scientihc progress in all lines of men- 

 tal activity. 



From prehistoric antiquity astronomers had patiently 

 observed and handed down their data. Mathematics aided 

 in the solution of the difficult problems that arose and 

 the greatest intellects had formulated theories of the con- 

 struction and mechanism of *the universe. Yet little of 



