\aii AMERICAN MEN OF]NCE 



There is no change in the general plan of thok. Arrangements were made to 

 include biographical sketches of the thousand leacmen of science of foreign nations 

 and to prepare a statistical study of their distrion, performance, etc. Material 

 for this purpose was partly collected, but the war mdifficult both the obtaining of the 

 material and objective judgments. The thousand ng American men of science who 

 died prior to the publication of the first edition of book have been selected by ob- 

 jective methods with a view to a scientific study. >w edition of this work published 

 five years hence may include biographical sketches he thousand leading foreign men 

 of science and of the thousand Americans who mane most important contributions 

 to science prior to the twentieth century. 



The first edition, compiled in 1904 and 1905 an(blished at the beginning of 1906, 

 contained about 4,000 biographies; the second editioublished at the end of the year 

 1910, about 5,500. In the present edition, publishfifteen years after the first, the 

 number is about 9,500. This increase may to someent be due to a more complete 

 collection of the material, but in the main measuithe increase in the number of 

 scientific men. 



After an interval of ten years, the thousand mehosc work for science has been 

 most valuable have been reselected. Stars are p^efi to the subjects of research for 

 these, as well as for those'who received this position inrevious edition. The selections 

 were made by a vote of the men competent in each nee some two thousand in all 

 being asked to take part, of^whom about one thous; complied. An account of the 

 methods of selection and a further study of the scientifituation are in course of prepara- 

 tion. In the present volume an appendix contains staiics and observations concerning 

 origins and families of American men of science. | * 



J. McKeEN C.A.TTELL 

 Garrison, N. Y. 

 May, 1921 



