September 16, 1904.] 



SCIENCE. 



373 



ter is American unity. Intercommunication, 

 common business interests and common na- 

 tional ideals are named as factors contributing 

 to this unity. 



The final chapter treats of ' Governmental 

 Study of our Domain.' It contains a descrip- 

 tion of the work of the Geological Survey, 

 Coast Survey, Fish Commission, Department 

 of Agriculture and other departments of gov- 

 ernmental activity. 



' Geographic Influences ' is almost a pioneer 

 in its line. Among the geographic influences 

 the author places the greatest emphasis upon 

 physiography, but the treatment is not over- 

 balanced. A quality which can hardly be 

 shown in a review is the vigorous, attractive 

 style. The author presents a wealth of facts 

 without a trace of ' statistical ' manner. The 

 illustrations are well selected and several maps 

 are included in the work. The book should 

 have a good circulation among those readers 

 who are interested in American history. It 

 will also appeal strongly to an increasing 

 number of students who are considering the 

 relations of the earth sciences to the politico- 

 historical sciences. 



F. V. Emerson. 



Cornell Universitt. 



DISCUSSION AND GOBRESPONDENCE. 



THE METRIC SYSTEM. 



To THE Editor of Science: I feel that I 

 must congratulate your readers on the review 

 of ' The Metric Fallacy,' published in your 

 issue for August 5, from the pen of Professor 

 W. Le Conte Stevens. Passing by the charges 

 of partisanship and intolerance for the mo- 

 ment, as of no real importance, the review ex- 

 hibits a comprehension of the subject which is 

 rare — I might almost say unique — among 

 metric advocates. My purpose in writing this 

 letter is to point out that Professor Stevens's 

 admissions are of far greater importance than 

 he seems to suspect, and I trust you will find 

 a place for it — not as a reply to the review, 

 nor as a defence of the book, but as a continu- 

 ation of an important discussion. 



As I have pointed out in a, special chapter 

 of 'The Metric Fallacy' (The Pro Metric 

 Argument), the metric advocates have based 



their case upon the belief that the change to 

 their system is an easy one. This belief is the 

 chief burden of the pro-metric statements made 

 before the house committee on coinage, weights 

 and measures, of the fifty-seventh congress, 

 and it was largely through its reiteration that 

 the favorable report of that committee was ob- 

 tained. In the above-named chapter will be 

 found quotations from the statements made 

 by a dozen metric advocates before that com- 

 mittee in which the longest period named for 

 the change is five years. I can, however, ask 

 you for space to repeat but one of these — the 

 gem of the whole collection — which came from 

 Lord Kelvin (italics mine) : 



I believe that in a fortnight people would be- 

 come so accustomed to the perfect simplicity and 

 easy working of the metrical system, that they 

 will feel that instead of its being a labor to pass 

 from one system to the other, it will he less than 

 no labor. 



This opinion, I should add, was repeated 

 with approval at the great discussion of the 

 American Society of Mechanical Engineers in 

 1902. 



Through a clipping bureau, I have received 

 from Great Britain hundreds of newspaper 

 clippings pertaining to this agitation in that 

 country, and the case there, as here, is based 

 upon this assumption. 



It would, indeed, be superfluous to mention 

 this contention of the metric advocates, ex- 

 cept to point out that Professor Stevens is so 

 far in advance of his associates as to frankly 

 tell us that ' reasonably complete assimilation 

 will take several generations ' and that ' none 

 of us of to-day will live to see anything better 

 than good progress on the part of the general 

 public in getting accustomed to the new stand- 

 ards and in losing devotion to the old ones.' 



Among those whose opinions as to the 

 shortness of the transition period are given in 

 the chapter on ' The Pro Metric Argument,' 

 are : Elihu Thompson, Harvey W. Wiley, S. 

 W. Stratton, Simon Newcomb and Lord Kel- 

 vin. Professor Stevens seems to think I have 

 not treated these opinions with due respect, 

 but in view of the above quotations from his 

 review it is hard to see wherein he respects 

 them more than I do. He plainly regards 



