536 



SCIENCE. 



[N. S. Vol. XIX. No. 483. 



have learned the metric system. They 

 need no weights but the gram with its deci- 

 mal multiples and divisions. The ounce 

 ought long ago to have been abolished or 

 defined as a definite fraction of the avoir- 

 dupois pound alone. Its abolition is much 

 preferable to its retention. 



An obvious advantage of dividing the 

 foot into 10 inches is that a cubic foot be- 

 comes 1,000 instead of 1,728 cubic inches. 

 The weight of the cubic foot of water be- 

 comes 31.25 pounds according to the sug- 

 gested definition of the pound. The reduc- 

 tion in length to 10 inches, furthermore, 

 makes it coincide very closely with the 

 length of the average masculine foot, while 

 12 inches is more than twenty per cent, too 

 long. 



The suggested length of the inch is be- 

 tween one per cent, and two per cent, less 

 than that of the present inch. Small as 

 this change may be, it constitutes the most 

 serious of all the changes suggested. The 

 practical standard of length in the United 

 States has been, not the yard or foot, but 

 the inch. In the construction and use of 

 all machinery inches and fractions of an 

 inch are the units of measurement. If a 

 screw-thread has been cut in accordance 

 with a gauge based on the inch, a change 

 of two per cent, in the inch would render 

 such a screw worthless for the same 

 machine. The mechanical engineers and 

 machine manufacturers will, therefore, 

 continue to be the most determined enemies 

 of metric reform. Should legislation be 

 adopted involving a change of standards, a 

 generous allowance of time ought to be pro- 

 vided, within which the machinists may 

 adapt new instruments to the new stand- 

 ards. Few, if any, machines can be ex- 

 pected to continue available more than ten 

 years. Such a period of grace would, per- 

 haps, be as much as could be reasonably 

 demanded. 



The pound equal to half a kilogram is 



about one tenth greater than the avoirdu- 

 pois pound. It is identical with the Ger- 

 man pfund and the French livre. Its 

 adoption by England and the United States 

 would make the pound a definite unit 

 readily understood throughout most of the 

 civilized world. It is now indefinite. 



A.ssigning the qualifier 'metric' to the 

 proposed units to distinguish them from 

 the old ones now in use in the United 

 States, their mutual relations are approxi- 

 mately shown in the following table : 



It is, of course, understood that the pro- 

 poser of any change whatever in the units 

 to which the American public is accus- 

 tomed will be adversely criticized, particu- 

 larly by the mechanical engineers and the 

 manufacturers of machine tools. Such 

 criticism can be borne with equanimity 

 if the compromise scheme just outlined 

 should lead to the practical adoption of 

 the metric standards and the decimal 

 system of weights and measures, with a 

 reasonable combination of the binary sys- 

 tem with it. The decimal system of coin- 

 age a century ago was regarded by some 

 critics as visionary, but it has stood the 

 test of time. 



W. LeConte Stevens. 

 Washington and Lee University. 



THE AUSTRALASIAN ASSOCIATION. 

 The biennial meeting of the Australasian 

 Association for the Advancement of Sci- 

 ence was held this year at Dunedin, New 

 Zealand. There was a large attendance of 

 members fi-om all the Australasian colonies 



