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 Epcar F. Smitu, 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- 
