THE INCORPORATORS 123 
Circle in 1843. In 1853 he was appointed Professor of Mathe- 
matics in the United States Naval Academy at Annapolis, Mary- 
land, and continued his work there until 1865. During the latter 
portion of this period, he was Professor of Astronomy and Navi- 
gation. 
The same year, 1865, he had charge of the American Ephem- 
eris and Nautical Almanac. This work was then published at 
Cambridge, Massachusetts, but the office was afterwards re- 
moved to Washington. Professor Coffin continued his labors in 
this connection until September, 1877, when he was retired from 
the Navy. He died at Washington, January 8, 1890. 
He published a number of articles on the phases of astronomy 
and mathematics to which he had given special study. 
JOHN ADOLPHUS BERNHARD DAHLGREN 
Born, November 13, 1809; died, July 12, 1870 
Admiral Dahlgren was born in Philadelphia on November 
13, 1809. His father, Bernhard Ullrik Dahlgren, a Swede, was 
obliged to leave his native country in 1804, owing to his advocacy 
of republican principles. He came to America in 1806, and his 
government having withdrawn its opposition he obtained the 
post of Swedish Consul at Philadelphia. John Dahlgren attrib- 
uted his inventive genius to his mother, while his desire for a 
seaman’s life was stirred by the sight of the ships that lay at 
the wharves, or at the Navy Yard, at Philadelphia. Com- 
mencing his education at the Quaker School, he made such prog- 
ress under the watchful care of his father that when application 
was made for a midshipman’s place in the Navy, the heartiest 
recommendations were received from his instructors. 
On the 12th of April orders came to proceed to Norfolk and 
report to Captain Barron for duty on the frigate Macedonia, 
sailing for Brazil. A cruise in the Mediterranean followed, 
with promotion to a lieutenancy. A little later he took part in 
the work of the Coast Survey. About this time a threatened 
loss of eyesight caused the young man to retire to a farm near 
Hartsville, Pennsylvania, and later he made a home for his 
