674 



SCIENCE 



[N. S. Vol. XXXII. No. 828 



course of the seven preceding years they have 

 about the same record. They tend to lose 

 about 250 places or about twice the average 

 of all the men on the list. The 24 men who 

 seven years ago were sixty-eight years of age 

 or older have nearly all lost in position. It is 

 not likely that any one of them has done any- 

 thing to lower his scientific reputation; but 

 men of the younger generation have accom- 

 plished work of greater importance, or the 

 work of older men is forgotten because it is 

 less contemporary. It thus appears that 

 under existing conditions in this country, 

 scientific men are likely in the course of seven 

 years to lose about 100 places. Men who have 

 obtained recognition among the thousand are 

 likely to gain if under forty; if between forty 

 and fifty they are likely to lose, and if over 

 fifty-five they are likely to lose more than the 

 average."" 



The average age of the thousand scientific 

 men on the list of 1910 is 48.12 years. The 

 age distribution is as follows: 



Age Number 



25-29 6 



30-34 54 



35-39 155 



40-44 214 



45-49 176 



50-54 137 



55-59 82 



60-64 68 



65-69 40 



70-74 33 



75-79 13 



80-84 7 



Unknown 15 



In Table VI. is given the average age of the 

 men in the ten groups of one hundred making 

 up the thousand for the lists of 1903 and 1910.' 

 The probable errors of the averages are less 



" The coefficient of correlation between age and 

 gain in position ia —31.7. It is, however, doubt- 

 ful whether the Galtou-Pearson method can be 

 used to advantage in such cases. 



" The list for 1903 used for ages consisted of 

 the 1,000 scientific men who stood first before the 

 adjustments had been made to secure a fixed 

 number in each science. 



TABLE VI. AVEEAGE AGE ACCOBDIWG TO POSITION 

 IN 1903 AND 1910 



than one year. It thus appears that the more 

 eminent scientific men are likely to be older; 

 but the difPerences are small apart from the 

 first hundred, who in 1903 were 5.1 years older 

 than the average, and in 1910 6.7 years older. 

 Scientific men do not become more eminent 

 as they grow older unless they have obtained 

 a good position at a comparatively early age. 

 The men on the list of 1910 are, on the 

 average, three years older than those on the 

 list of 1903. An increase in age would be 



TABLE VII. AGES AT WHICH THE BACHELOR'S DE- 



GEEE AND THE DOCTOBATE OP PHILOSOPHY WEBE 



EECEIVED ACCOBDING TO SCIENCE AND TO 



POSITION IN THE THOUSAND 



Mathematics . . 



Physics 



Chemistry. . . . 

 Astronomy. . . 



Geology 



Botany 



Zoology 



Physiology. . . . 



Anatomy 



Pathology. . . . 

 Anthropology . 

 Psychology. . . 



No. or average 



I 



II 



Ill 



IV 



V 



VI 



VII 



VIII 



IX 



X 



No. or average 



Bachelo 



67 



112 



132 



34 



85 



83 



117 



29 



15 



30 



21.9 

 22.1 

 21.6 

 21.6 

 22.8 

 23.7 

 22.6 

 21.7 

 23.7 

 20.7 

 22.0 

 21.7 



22.2 



21.6 

 21.9 

 22.3 

 22.2 

 22.2 

 22.0 

 22.4 

 22.2 

 22.8 

 22.8 



Ph. D. 



No. Age. 



64 

 87 

 114 

 14 

 43 

 56 

 96 

 19 

 2 



28.4 

 28.6 

 26.7 

 29.3 

 28.5 

 30.5 

 28.8 

 26.7 

 30.5 

 27.2 

 27.5 

 27.6 



2S.4 



26.9 

 27.3 



27.7 

 27.5 

 28.2 

 29.3 

 28.6 

 28.8 

 29.3 

 29.1 



544 28.4 



