AIM AND PROGRESS OF PHYSICAL SCIENCE. 365 



he attained, consume far more time than is really re- 

 quired to make actual observations or experiments. How 

 much more ingenuity and thought are expended in 

 bringing a refractory piece of brass or glass into sub- 

 jection, than in sketching out the plan of the whole 

 investigation ! Each of you will have experienced such 

 impatience and over-excitement during work where all 

 the thoughts are directed on a narrow range of ques- 

 tions, the import of which to an outsider appears trifling 

 and contemptible because he does not see the end to which 

 the preparatory work tends. I believe I am correct in 

 thus describing the work and mental condition that pre- 

 cedes all those great results which hastened so much the 

 development of science after its long inaction, and gave 

 it so powerful an influence over every phase of human 

 life. 



The period of work, then, is no time for broad com- 

 prehensive survey. When, however, the victory over 

 difficulties has happily been gained, and results are secured, 

 a period of repose follows, and our interest is next 

 directed to examining the bearing of the newly esta- 

 blished facts, and once more venturing on a wider survey 

 of the adjoining territory. This is essential, and those 

 only who are capable of viewing it in this light can 

 hope to find useful starting-points for further investi- 

 gation. 



The preliminary work is followed by other work, treat- 

 ing of other subjects. In the course of its different 

 stages, the observer will not deviate far from a direction 

 of more or less narrowed range. F'or it is not alone of 

 importance to him that he may have collected information 

 from books regarding the region to be explored. The 

 human memory is, on the whole, proportionately patient, 

 and can store up an almost incredibly large amount of 

 learning. In addition, however, to the knowledge which 



