250 B. A. Gould — Address, etc. 



that the question is now definitely disposed of. The inference 

 is justified that there is no appreciable difference of length be- 

 tween the two standards. Although the Metre des Archives 

 is an end-meter, or metre-a-bouts, made of a relatively soft and 

 flexible metal and its extremities adjusted by filing, while the 

 International Prototype gives the meter by the distance be- 

 tween delicate lines traced upon platiniridium, yet the prob- 

 able error of the comparison, which gives zero as the difference 

 of length, cannot exceed one micron, a limit of error twenty-five 

 times smaller than the tolerance fixed upon by the constructors 

 of the original standard. 



It has seemed to me that this sketch of some of the work 

 of the International Bureau would have interest for you, as 

 showing the advances made in metrology during the present 

 year. Other important physical researches for metrological 

 purposes are in prosecution and promise valuable results, at 

 least from a scientific point of view. Meanwhile the compari- 

 son of the chief standards of most countries, whether metric or 

 otherwise, including geodetic bars and those possessing historic 

 value or interest, has been steadily going on, and most of those 

 standards of length which are now, or have in comparatively 

 recent time, been employed in important measurements, have 

 now been compared with the International Prototype. 



During the current year our efficient Secretary has dis- 

 tributed nearly 4,500 metric charts, and as many pamphlets, 

 circulars and blank petitions, — as you will learn from his re- 

 port. It is impossible that these should not bring in due time 

 a, fitting return, in the shape of renewed interest throughout 

 the land in the reforms for which we are striving. 



In these remarks I have referred chiefly to the metric sys- 

 tem of weights and measures, upon which by common accord 

 the efforts of our society are at present concentrated ; leaving 

 aside most of its many other ends. Let us trust that by com- 

 mon effort the first victory may soon be achieved and leave us 

 freer to prosecute some of the other purposes of the society. 

 This requires individual effort, exerted according to organized, 

 method. 



