Alfred Vail's Letter to Joseph Henry (July 17, 1846)

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Letter from Alfred Vail, assistant to Samuel F. B. Morse, inventor of the first telegraph, to Joseph Henry, then a professor at Princeton University and later first Secretary of the Smithsonian Institution, July 17, 1846. In the letter, Vail apologizes for offending Henry by not crediting Henry's work in electromagnetism in Vail's publication on Morse's telegraph. Though Morse was credited with having invented the first telegraph, Henry asserted that Dr. Leonard Gale, who advised Morse on his first model of an electromagnetic telegraph, was able to correct imperfections in the model because of his knowledge of Henry's principles.


  • Henry, Joseph 1797-1878
  • Gale, Leonard D (Leonard Dunnell) 1800-1883
  • Morse, Samuel Finley Breese 1791-1872
  • Princeton University


Historic Images of the Smithsonian


The accompanying PDF contains SIA2012-0974 and SIA2012-0975, pages scanned from the edited transcript of the original version and notes in the Joseph Henry Papers Volume 6, pages 450-451.

Contained within

  • Smithsonian Institution Archives, Record Unit 7001, Box 8, Folder: 21 - July-September 1846
  • Rothenberg, Marc, et al, eds., The Papers of Joseph Henry, Volume 6, The Princeton Years: January 1844-December 1846 (Washington: Smithsonian Institution, 1992), 450-451

Contact information

Institutional History Division, Smithsonian Archives, 600 Maryland Avenue, SW, Washington, D.C. 20024-2520,


July 17, 1846

Restrictions & Rights

No restrictions


  • Telegraph
  • Publications
  • Inventors
  • Secretaries
  • Models (representations)
  • Letters
  • Controversies
  • Inventions
  • Science
  • Electromagnets
  • Models
  • Electromagnetism


United States


  • Document
  • Paper

ID Number

SIA2012-2890 and SIA2012-2891 and SIA2012-2892

Physical description

Number of Images: 3 ; Color: Color ; Size: 8w x 10h ; Type of Image: Document ; Medium: Paper

Full Record

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