174 NATIONAL ACADEMY OF SCIENCES 



campaign, and later, as a volunteer engineer officer, in the 

 Philadelphia Militia, was present at the battles of Gettysburg 

 and Antietam. 



In his connection with the National Academy of Sciences, 

 Professor Rogers made a study of the compasses of the iron 

 vessels used in the service of the Government. This investigation 

 led him to write a treatise on the " Magnetism of Iron Vessels " 

 which was published in the van Nostrand Science Series. 



Severing his connection with the University of Pennsylvania 

 in 1881, after being nine years a trustee of that institution, Pro- 

 fessor Rogers became chairman of the Committee on Instruction 

 at the Academy of Fine Arts, reorganized its system and 

 rendered valuable services in other directions for several years. 



Professor Rogers was one of the founders of the Union League 

 Club of Philadelphia. He exhibited the versatility of his mind 

 by writing a treatise on horsemanship and a manual of coaching, 

 in which he endeavored to show that these arts were properly 

 based on scientific principles. Credit for suggesting to Professor 

 Muybridge the principle to be employed in photographing 

 animals in motion has been given to Professor Rogers and modi- 

 fications of this principle form the basis of the present day 

 biograph and cinematograph. He died at Vienna on August 

 22, 1900. 



He was the first Treasurer of the National Academy of Sciences 

 and served in that capacity for eighteen years. 



(From Edgar F. Smith, in Biographical Memoirs of the National Academy 

 of Sciences, vol. 6, 1909, pp. 93-107.) 



ROBERT EMPIE ROGERS 

 Born, March 29, 1813; died, September 6, 1884 



Robert Empie Rogers was the youngest of four brothers, all 

 of whom became eminent as men of science. His father. Dr. 

 Patrick Kerr Rogers, emigrated from Ireland in 1798, and 

 after living in Philadelphia and Baltimore for several years, 

 became Professor of Natural Philosophy and Mathematics in 

 William and Mary College. Robert who was born at Balti- 



