586 



NA TURE 



[October ii, 1894 



of the sun was ^^ of the circumference of the heavens, or one- 

 half a degree of arc. 



It is impossible here to trace the evolution of time-measuring 

 from the earliest period to the present, and it is unnecessary, 

 because most of the steps are doubtless well known to you all. 

 You are requested to reflect, howei-er, upon the close reLv.ion 

 of the various stages of this evolution to the progress of the 

 human race from savagery to enlightenment. 



Hardly anything is a more certain and sensitive index of the 

 advancement of a people than the precision required in the time 

 schedule of the ordinary events of life. Improvement in time- 

 measuring instruments, watches and clocks, is in response to a 

 demand for this precision, and not the cause of it, as is some- 

 times asserted. Watches are now regulated to seconds where 

 formerly minutes were near enough, and the few remaining 

 civilised people among « horn the hour has been the smallest 

 division of time in common use, are fast mending their ways in 

 this respect. 



Unfortunately in the development of systems of measurement 

 of length and mass, we have not succeeded as well as with the 

 measurement of time. The greater excellence of the latter is 

 unquestionably due to the universality of the fundamental unit, 

 which is everywhere the day. While there have existed some 

 differences among different nations as to the divisions and 

 multiples of this unit, ceriain natural phenomena have directed 

 all, along nearly the same lines, and at this moment, in all 

 essential particulars, the chronometric systems of nearly all 

 civilised nations are identical. Although not the best that could 

 have been devised had existing knowledge and experience been 

 available in the beginning, the prevailing subdivisions of the 

 time unit are not seriously objectionable, and as they are so 

 nearly universal and so firmly established by long usage, they 

 are .almost certain to continue unchanged. 



In measures of length and masaor weight, the tendency from 

 the beginning, up to a very recent period, has been, as in the 

 case of time, towards the selection of natural units. 



Dimly comprehending the importance and necessity of in- 

 variable units of measure, primitive man looked to nature to 

 find the invariable. The nomenclature of every system of 

 measure known bears testimony to the original use of natural 

 units. Of measures of length familiar to all may be mentioned 

 the hand, foot, pace, fathom, cubit, ell and span, all of which 

 are derived from the dimensions of the human body. The inch, 

 as everybody knows, was originally the length of three barley- 

 corns from the middle of the ear, placed end to end. At a 

 later period among some of the Oriental nations the unit of 

 length was the length of a bamboo pipe, which when blown 

 would produce a certain musical pitch. This argues a reckless 

 indifference as to units of length, or an extraordinary power of 

 detecting variation in the pilch of musical tones. 



Units of weight or mass also had their origin in natural 

 magnitudes, although in this case much greater difficulty is 

 experienced. Almost the only natural unit of mass that was 

 suggested or used was the mass of a grain of wheat from the 

 middle of the ear, and from this our use of the grain weight of 

 today is derived. 



Uut all men are not alike in stature, nor arc grains of wheat 

 of great uniformity in dimensions or mass. As might have been 

 anticipated, under such conditions there grew up, not only in 

 different parts of the world, but in different sections of the same 

 country, a variety of systems of weight and measure having no 

 exact relations to each other, or among themselves, and which 

 developed, as intercourse between nations became easier and 

 more general, into one of the greatest calamities ever visited 

 upon mankind. Various efforts were made at various times by 

 various nations, each to improve its own system, but little good 

 resulted up to almost exactly one hundred years ago. At the 

 close of the Revolutionary War the weights, measures and coins 

 in use in this country were almost innumerable in kind. 

 Although mostly inherited from our Anglo-Saxon ancestors, 

 many other European systems had gained a foothold, and con- 

 siderable diversity in names and values had grown up through- 

 out the colonics. An (■pporluniiy was presented at that time 

 which we shall never see again, .and which wa-; lost by what 

 one is forced to call the moral cowardice of men in high 

 places. No one appreciated this opportunity more thoroughly 

 than Thomas Jefferson, perhaps the most scholarly man 

 of his time ; the patron and (riend of science and scientific 

 ■ncD. 



Jefferson recognised the incongruitiei of existing systems of 



NO. 1302, vol. 50] 



weight and measure, but not wishing to depart sensibly from 

 the foot as a unit of lencth he offered ingenious suggestions for 

 a perfected scheme of linear measurerrent in which tl'e foot 

 wa<; to be related decimally to the lengihof a sec >nds' pendulum 

 and was to be decimally ^^bdivide■^. 



The Constitution of the United States provides fat Congress 

 shall have po«er to coin money, regulate the valu= thereof, and 

 to fix the standard of weights and measures. At an early day 

 this power was wisely exercised lo provide escape from the 

 bondage of the unphilosophical pounds, shillings and pence of 

 the mother country by the establishment of a decimal system 

 of coin ratios, the use of which during the past hundred years 

 has been a greater gain, as compared wiih the discarded system, 

 than the value of all the money in the country at the time of its 

 adoption. 



The second prerogative, that of " fixing a standard of weights 

 and measures," was not at that lime and, as a matter of fact, 

 has never yet been exercised by Congress ; indeed, considering 

 the great danger which continually existed that when Congress 

 did ac it would act wrongly, it is a matter of congratulation 

 that legislation on this important matter has thus far practically 

 gone by default. But the opportunity existing during the early 

 days of our national life was great, for the reason that just at 

 this time there was conceived and perfected on the other side 

 of the .\tlantic the most decided, the most important, and the 

 most far-reaching advance in metrology that the world has ever 

 seen. 



It had its beginning in the wisdom and foresight of the 

 distinguished Talleyrand, who in 1790, while still a bishop, 

 impressed by the excessive diversity .and confusion of the 

 weighls and measures then prevailing, proposed'tothe Assembly 

 of Franc-e a scheme for their reform.ation. Realising that not 

 only national but international reformation was desirable, other 

 nations were invited to join in the development and execution 

 of this magnificent scheme. The co-operation of the Royal 

 Society of London and of the English Givernment was sought, 

 but unfortunately the English were not then in the mood for 

 giving support to the Ercnch. 



For the preliminary steps, looking to the determination of 

 the value of the fundamental units and their relation to each 

 other, a committee of the French .-Vcaileniy, including the most 

 eminent mathematicians of Europe, was appjinted, among its 

 members being Borda, Lagr.ange, Laphice and Condorcet. 

 Others engaged in the v.arious measurements necessary to this 

 determination were Lavoisier, Coulomli and Delambre. 



Throughout the stormy scenes that accompanied the great 

 political and social changes which occurred in France during 

 the last decade of the eighteenth century, these noble scholars 

 steadfastly pursued the problem upon the solution of which they 

 had set out. At one time Horda, Lavoisier, Lapl.ice, Coulomb 

 and Delambre were dismissed from this public service by 

 Robespierre's Committee of Safety, because their political 

 views were suspected of being not quite in harmony with those 

 of the aggressive paity in power. (That was a hundred years 

 ago.) IJut Robespierre was ambitious as well as cruel, and the 

 project was afterwards allowed to go on. Finally, on June 22, 

 1799, the two new perfected standards — a metre, the unit of 

 length, made of platinum, and a kilogramme, the unit of mass, 

 of the same metal, were presented with great solemnity at 

 the bar of both houses of the National As.sembly of France by 

 tlie celebrated Laplace, who addressed the assembled legis- 

 lators ; and on the same day the two standaids were deposited 

 in the archives of France, destined to be, a century later, the 

 accepted units of measure of more than half of the civilised 

 world, and eventually to become universal. In a report filed 

 just seventy-three years ago to-day, John i^hiincy Adams, then 

 Secretary of State, s.ays of this event : " I'he spectacle is at 

 once so rare and so sublime . . . that not to p.ause for a 

 moment, were it even from occupations not essentially con- 

 nected with it, to enjoy the contemplation of a scene so 

 honourable to the character and capacities of our species, 

 would argue a want of sensibility to appreciate its worth." 

 "Ibis ^ccne," he siiys, "formed an epoch in the history of 

 man, and an example and an admonition to the legislators of 

 every nation, and of all after-times." 



Just one hundred years ago, in 1794, copies of the preli- 

 minary metric standards were sent 10 this country, and our 

 Government was urged lo join in this niemnrable undertaking. 

 Then, and during the thirty years following, the question of our 

 adopting a system of weights and measures in harmony with our 



