i88 POPULAR SCIENCE MONTHLY. 



on a perfectly faultless basis would, at the same time, rescue our weiglits 

 and measures of capacity from their present utter confusion. 



In presence of the opinion thus expressed and thus supported 

 by evidence, we ought, I think, to hear nothing more about 

 "ignorant prejudice" as the only ground for opposition to the 

 metric system now being urged upon us. But, before proceeding 

 to give adverse reasons of my own, let me quote a further objec- 

 tion — not, it may be, of the gravest kind, but one which must be 

 taken into account. Writing from Washington, Prof. H. A. 

 Hazen, of the United States Weather Bureau, published in Na- 

 ture of January 2, this year, a letter of which the following 

 extracts convey the essential points : — 



The metric system usually carries with it the Centigrade scale on the 

 thermometer, and here the whole English-speaking world should give no 

 uncertain sound. In meteorology it would be difficult to find a worse scale 

 than the Centigrade. The plea that we must have just 100° between the 

 freezing and boiling points does not hold; any convenient number of 

 degrees would do. The Centigrade degree (1°"8 F.) is just twice too large 

 for ordinary studies. The worst difficulty, however, is in the use of the 

 Centigrade scale below freezing. Any one who has had to study figures 

 half of which have minus signs before them knows the amount of labor 

 involved. To average a column of 30 figui*es half of which are minus 

 takes nearly double time that figures all on one side would take, and the 

 liability to error is more than twice as great. I have found scores of errors 

 in foreign publications where the Centigrade scale was employed, all due 

 to this most inconvenient minus sign. If any one ever gets a " bee in his 

 bonnet " on this subject and desires to make the change on general prin- 

 ciples it is very much to be hoped that he will write down a column of 30 

 figures half below 32° F., then convert them to the Centigrade scale, and 

 try to average them. I am sure no English meteorologist who has ever 

 used the Centigrade scale will ever desire to touch it. 



But now, having noted these defects, which may perhaps be 

 considered defects of detail, since they do not touch the funda- 

 mental principle of the metric system, I propose, with your per- 

 mission, to show that its fundamental principle is essentially 

 imperfect and that its faults are great and incurable. 



II. 



In reply to my inquiries, a French friend, member of the Con- 

 seil d'Etat, after giving instances of nonconformity to the metric 

 system, ended by saying : — " En adoptant le syst^me mdtrique deci- 

 mal, on n'a pas fait disparaitre tout k fait les denominations 

 anciennes, mais on en a fortement rdduit Temploi." [By adopt- 

 ing the decimal metric system, we have not made the old denomi- 

 nations to disappear entirely, but we have greatly reduced their 

 use.] 



It is now more than a century since, in the midst of the French 

 Revolution, the metric system was established. Adoption of it 



