26 RECORDS 



lines of thought very different from the lines followed by our prede- 

 cessors ; and the fact that we do not visualize equally clearly all 

 these systems shows the experience of humanity with physical 

 phenomena has been extremely limited. Most curious and in- 

 structive are the system in which length does not appear explicitly 

 and the system in which time does not appear explicitly. May 

 we not see in these systems opportunities respectively for the 

 development of those individuals of our race who seem to possess 

 no realization of distance or no conception of time ? 



Confining attention to the simpler and more familiar units of 

 length, mass, and time, and to a few of the more complex quan- 

 tities expressed thereby, let us first consider briefly the present 

 status of these fundamental units and the possibility of maintain- 

 ing their invariability. The standards of length and mass which 

 are now^ universally adopted in science are the meter and the kilo- 

 gram respectively, carefully intercompared copies, or "proto- 

 types," of which have been distributed by the international 

 bureau of standards to the nations contributing to the cost 

 thereof The United States possesses two copies of each of 

 these prototypes, and they are, as a matter of fact, our effective 

 working standards, even for the production of standard yards 

 and pounds. It is to be hoped, therefore, that the end of the 

 barbaric system of "weights and measures," we have inherited 

 from an unscientific ancestry, is near at hand, and this not so 

 much in the interest of men of science as in the interests of those 

 less w^ell fitted to struggle with the ingenious intricacies of the 

 British system. 



These prototype meters and kilograms are known in terms of 

 the adopted standards, and hence in terms of one another, with 

 a degree of precision which verges close to the limits of the con- 

 stancy of matter itself Thus the lengths of the meters are 

 known with an uncertainty expressed by a probable error of 

 only one part in five millions. This degree of refinement cor- 

 responds to about one hundredth of an inch in a mile, or to 

 about nineteen miles in the mean distance of the earth from the 

 sun. But this admirable precision is greatly surpassed by that 

 of the kilograms, whose uncertainty falls to one part in five hun- 



