Febkuabt 11, 1916] 



SCIENCE 



191 



standing their great value, were discarded 

 as soon as better gratings were produced. 



The simplest of instruments have often 

 been the means of making great discoveries. 

 Faraday and Henry worked with the most 

 simple tools. Many discoveries as far 

 reaching as any will again be made with 

 the simplest apparatus ; but advancement in 

 other directions can only be effected after 

 the highest possible development of instru- 

 ments and processes. 



Some men by devising what appeared to 

 be a little improvement in a machine have 

 indirectly advanced science more than 

 would many painstaking investigations. 

 Instruments like the Crookes' tube lead to 

 the discovery of facts that were entirely 

 unsuspected and unsought; and similarly 

 many instruments have been developed for 

 one purpose and then found to be of value 

 in an entirely different field. We have 

 seen many problems solved which at first 

 appeared beyond the possibility of demon- 

 stration or accomplishment. There seemed 

 no possible method of approach. There 

 were no instruments with which the re- 

 sults could be attained. Photography, 

 wireless telephony, counting atoms, and see- 

 ing the tracks of atoms and of fragments 

 of atoms, are some of the accomplishments 

 which not so many years ago would have 

 been considered beyond the range of pos- 

 sibility. 



Many instruments are used as tools to 

 perform certain definite functions in a more 

 complex system, and, as such, should be so 

 constructed as to require the least possible 

 attention. As far as it is practicable the 

 instrument should read directly the quan- 

 tity desired. We already have many such 

 instruments, as, for example, the ammeter, 

 voltmeter, fiuxmeter, potentiometer, Wheat- 

 stone bridge, direct reading spectrometer, 

 and the recently devised instruments for 

 giving directly the length of electromag- 



netic waves and their logarithmic decre- 

 ment. The "artificial eye," also recently 

 devised, gives in the photometry of colors 

 results equivalent to that of an average 

 eye, eliminating the necessity of several ob- 

 servers. In the measurement of conductiv- 

 ity an apparatus has been so assembled as 

 to give directly the resistance in microhms 

 per cubic centimeter. Self-recording in- 

 struments of all kinds are a great conve- 

 nience and in many operations practically 

 indispensable. 



The intricacy and difficulty of many 

 operations which often retard progress 

 should be removed as far as possible. 

 Every instrument improved to give greater 

 convenience and greater simplicity in 

 operation, makes it possible for all who use 

 it to concentrate their whole energy on that 

 part of their work which has real signif- 

 icance. This adds much to efficiency and 

 productivity in science. 



I msh to emphasize the importance of 

 using the best and most convenient instru- 

 ments obtainable for any given purpose. 

 We may learn from manufacturing estab- 

 lishments the advantage of discarding ap- 

 paratus that has become obsolete or not 

 suited for our particular purpose. In no 

 other way can our output become what it 

 should be. 



There are many problems pressing for 

 solution, and every unexplained phenom- 

 enon may hold in store still more problems 

 or strange relationships and unknown 

 entities. Most of the solutions can be made 

 only with the aid of scientific instruments. 



We want to know something definite 

 about the nature of gravitation and of the 

 ether. We want to understand more com- 

 pletely the structure of atoms and mol- 

 ecules. We want to know the structure of 

 corpuscles and nuclei. We want to under- 

 stand the interatomic and intermolecular 

 forces. We want to know what determines 



