636 



SCIENCE 



[N. S. Vol. XXXII. No. 827 



lumbia laboratory of psychology to measure 

 the validity of beliefs, the beauty of pictures, 

 differences in traits of character, literary skill 

 and efficiency in various performances. 



The method used enables us to measure not 

 only differences in scientific merit, but also 

 the accuracy of judgment of those who make 

 the arrangements. It would be possible to de- 

 termine whether those more eminent have the 

 more accurate judgments, at what age the 

 individuals are most competent and the like. 

 As a matter of fact, the judgments in the 

 present case were made by those most eminent 

 in each science who were willing to undertake 

 the task. Of the ten in each science who were 

 placed at the head of the list in the previous 

 study," or 120 in all, 80 consented to under- 

 take the arrangement, and of these 68 sent in 

 valid lists. Others in the order of eminence 

 were then asked until ten lists were obtained 

 in each science. This study has thus only 

 been made possible by the cooperation of those 

 whose time is of much value. My personal 

 obligations to them are very great. 



The names of those selected for arrange- 

 ment included all who were known to have 

 done research work of any consequence, and 

 those who arranged them were asked to add 

 any who had been omitted. Some names de- 

 serving consideration were doubtless neglected 

 and consequently would not find a place in 

 the first or second thousands as ultimately 

 selected. Each of those included in the first 

 group is probably among the leading thou- 

 sand scientific men in the United States, but 

 there are a few others who belong to this 

 group though not included. It might be a 

 service to science to print the list of our 

 thousand leading scientific men in the order 

 of merit together with the probable error of 

 each position, but it would require courage to 

 do this, and perhaps it would not be possible 

 to obtain the arrangement if it were to be 

 made known. In the " Biographical Directory 



' Six were not asked owing to their illness or 

 absence from the country. These conditions also 

 account for a number of those who did not reply 

 to the letter or did not consent to make the 

 arranErement. 



of American Men of Science " those are indi- 

 cated by stars who belong either to the group 

 as selected seven years ago or as selected now. 

 Those who have won a place in the group can 

 be identified by a comparison of the two edi- 

 tions of the book. Those who have lost their 

 places in the group can not be known. 



The arrangements of each of the two lists 

 extended over a period of some months. The 

 first list may be dated as approximately of 

 January 1, 1903, and the second list as ap- 

 proximately of January 1, 1910. The distri- 

 butions given in the previous paper refer 

 approximately to January 1, 1906, the resi- 

 dences and positions used being those given in 

 the first edition of the directory. For the 

 present list, the residences and positions are 

 those of January 1, 1910. It would be better 

 if the arrangement of the first list and the 

 distributions referred to the same date, but it 

 was not possible to work up the data more 

 promptly, as the writer was able to attend to 

 the compilation of the directory and the 

 statistics only during the summer months. 

 In collecting and compiling the data he has 

 had the very valuable assistance of Professor 

 V. A. C. Henmon, of the University of Wis- 

 consin, and of Mr. E. K. Strong, Jr., fellow in 

 psychology in Columbia University. 



Those included in the list of 1903 who died 

 prior to 1910 number 58. It is a roll of honor 

 which may be given here : 



1903 (in part) 



