SCIENCE 



A WEEKLY JOURNAL DEVOTED TO THE ADVANCEMENT OF SCIENCE, PUBLISHING THE 



OFFICIAL NOTICES AND PROCEEDINGS OF THE AMERICAN ASSOCIATION 



FOR THE ADVANCEMENT OF SCIENCE. 



Editorial Committee : S. Newcomb, Mathematics ; R. S. Woodwaed, Mechanics ; E. C. Pickering, 

 Astronomy ; T. C. Mkndenhall, Physics ; R. H. Thurston, Engineering ; Iea Remsen, Chemistry ; 

 Charles D. Walcott, Geology ; W. M. Davis, Physiography ; Henry F. Osborn, Paleon- 

 tology ; W. K. Brooks, C. Hart Meeriam, Zoology ; S. H. Scuddee, Entomology ; C. E. 

 Bkssey, N. L. Britton, Botany ; C. S. Minot, Embryology, Histology ; H. P. Bow- 

 ditch, Physiology ; J. S. Billings, Hygiene ; William H. Welch, Pathol- 

 ogy ; J. McKeen Cattell, Psychology ; J. W. Powell, Anthropology. 



Feidat, June 20, 1902. 



CONTENTS: 



Measurement and Calculation: Professor R. 

 S. Woodward 961 



'Natural History,' '(Ecology' or 'Ethology' : 

 Professor William Morton Wheeler... 971 



The Law of von Baer: Otto C. Glaser 976 



Membership of the Am,erican Association . . . . 982 



Scientific Books : — 



Barharin's La geometrie non-Euclidienne: 

 Dr. George Bruce Halsted. Packard's 

 Life of Lamarck: Professor William A. 

 LocY 984 



Societies and Academies: — 



The Botanical Society of Washington : 

 Dr. Herbert J. Webber 989 



Discussion and Correspondence: — 



What is Nature Study? Professor W. J. 

 Beal. (Ecology: Db. F. A. Bather. Mass 

 and Weight : Carl Hering 991 



Shorter Articles: — 



Divergence of Long Plumb-lines at the 

 Tamarack Mine: Professor F. W. Mc- 

 Nair. Sex in Seed Plants: Professor 

 Francis Ramaley 994 



Harvard College Observatory Astronomical 

 Bulletin: Professor Edward C. Picker- 

 ing 996 



A Graduate School of Agriculture 997 



Scientific Appointments under the Govern- 

 ment 997 



The Pittsburgh Meeting of the American As- 

 sociation : George A. Wardlaw 998 



Scientific Notes and News 998 



University and Educational News 999 



MSS. intended for publication and books, etc., intended 

 fir review should be sent to the responsible editor, Pro- 

 lessor J. McKeen Cattell, Garriaon-on-Hudaon, N. Y. 



MEASUREMENT AND CALCULATION.* 



In my address of a year ago I sought, in 

 a summary way, and by concrete illustra- 

 tion, to indicate how science originates in 

 and advances with observation and experi- 

 ment. I woidd now invite your attention 

 to a similar consideration of the role which 

 measurement and calculation play in the 

 higher developments of science. 



All sciences are at first qualitative. They 

 pass in their growth from the fact-gather- 

 ing stage of imrelated qualities to the or- 

 derly stage of related qualities and thence 

 upward to the stage of quantitative corre- 

 lation under theory. Such, at any rate, has 

 been the course of all sciences hitherto de- 

 veloped, and it seems safe to predict that 

 such will be the course of those which may 

 arise in the future. The recognition of this 

 fact is of prime importance. It helps us to 

 understand the great relative diversity in 

 perfection among the sciences ; it affords a 

 basis for rational optimism with respect to 

 the continued progress of science; and it 

 ought to make the specialists of the older 

 sciences less contemptuous than they some- 

 times are in their attitude toward the newer 

 ones which have not yet passed the 'rock- 

 naming and bug-hunting stage.' 



Whenever a quantitative relation be- 



* Address of the retiring President of the New 

 York Academy of Sciences, read February 24, 

 1902. 



