64 HEREDITY AND DEVELOPMENT OF NAVAL OFFICERS. 



14. JOHN ADOLF DAHLGREN. 



JOHN ADOLF DAHLGREN was born at Philadelphia, Pennsylvania, Novem- 

 ber 13, 1809. He was forced by the early death of his father to earn a living at 

 the age of 15. Having only one strong taste, he applied for admittance to the navy 

 as midshipman, but was not successful until February 1, 1826. After six years 

 of service he successfully passed his examination. On account of his proficiency 

 in mathematics he was detailed, in 1834, to the United States Coast Survey under 

 Hassler, and entered upon triangulation work, particularly the measurement of 

 the base on Long Island. In 1836 Dahlgren was made second assistant of the 

 survey, with direction of a triangulation party. On account of eye-strain, Lieu- 

 tenant Dahlgren visited France for relief and was obliged to retire to a farm from 

 1838 to 1842, but during this period he reported on the rocket-firing system of the 

 French army. For a year or two he resumed active service in the navy and on the 

 outbreak of the war with Mexico he was assigned to ordnance duty, especially 

 in the rocket department. Having by experimentation proved the defects in the 

 naval guns then in use, he devised first, in 1850, a light howitzer for small-boat use 

 and then his 9-inch and 11-inch shell-guns, which introduced new principles into 

 naval armament. He published technical books on ordnance and brought the ord- 

 nance department of the navy to great system and perfection. In 1857 he was 

 given charge of the sloop of war Plymouth, of less than 1,500 tons, with permission 

 to arm and equip her as he thought best. With her battery of 4.7-inch and 

 1.9-inch guns she became the most formidable craft afloat. In his voyage with the 

 Plymouth, Commander Dahlgren was able to settle various diplomatic difficulties 

 with other countries. Dahlgren experimented next on rifled cannon and urged 

 the construction of ironclads, but his recommendations led to no response from an 

 unprogressive naval board, and the Civil War found the government unprepared. 

 Dahlgren's guns, nevertheless, won many important victories in the years that 

 followed. Dahlgren was tremendously active on the Chesapeake and Patriotic; he 

 was appointed chief of the bureau of ordnance with rank of captain in July 1862, 

 and armed and equipped ironclads. As rear admiral from February 1863, he closed 

 the Atlantic ports of the Confederacy. From 1868 to 1870 he was again chief of the 

 ordnance bureau, and a few months before his death was appointed, for the second 

 time, commandant of the Washington navy yard. He died in July 1870. 



The most striking trait shown by Dahlgren was a desire to go into the navy. 

 This is quite possibly a nomadic trait; certainly there is an appeal of the sea, 

 as such. In the letter sent with his application for admission to the navy, at 15 

 years of age, occur such phrases as: "The decided wishes of John are for the 

 navy and a seafaring life and no other object has any temptation for him." Again, 

 "He is . . . so passionately bent on the destination of the navy of the United 

 States that he can not be diverted from it," and he himself writes: "Having long 

 been anxious to adopt as a profession the naval service of my country . . ." This 

 desire for the navy was seen in his younger brother William, who, owing to a mis- 

 understanding with John, vowed he would never be known as Dahlgren again; 

 so he assumed his mother's name and thereafter was called William de Rohan. 

 The National Cyclopedia of American Biography (V, 24) states of William: 



"He went to Europe, where his family connections and ample means brought 

 him into intimacy with persons of the highest rank in life, including Admiral Hobart 

 (Pasha), with whom he took service under the Sultan, with the rank of captain. 

 Leaving the Turks, he went to the Argentine Republic with Garibaldi and com- 



