Joseph Henry's Letter to George Mifflin Dallas (August 12, 1847)

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Letter from Joseph Henry, first Secretary of the Smithsonian Institution, to George Mifflin Dallas, Vice President of the United States, August 12, 1847. In the letter, Henry responds to Dallas's inquiry about the danger of a lightning strike to a proposed mast and lantern to be erected in the United States Capitol Building's dome. Henry states that "the tendency of the lightning to fall on the Capitol will be increased by the action of the proposed fixture."


  • Dallas, George Mifflin 1792-1864
  • United States. Office of the Vice President
  • United States Capitol (Washington, D.C.)


Historic Images of the Smithsonian


  • The accompanying PDF contains SIA2012-0448, SIA2012-0449, SIA2012-0450, and SIA2012-0451, which are pages scanned from the edited transcript of the original version and notes in the Joseph Henry Papers Volume 7, pages 158-161 (Document 89).
  • This document is written in an unknown handwriting, but the signature is that of Joseph Henry.

Contained within

  • Smithsonian Institution Archives, Record Unit 7001, Box 9, Folder: 1 - August - September 1847
  • Rothenberg, Marc, et al, eds., The Papers of Joseph Henry, Volume 7, The Smithsonian Years: January 1847-December 1849 (Washington: Smithsonian Institution, 1996), 158-161

Contact information

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


August 12, 1847

Restrictions & Rights

No restrictions


  • Secretaries
  • Lightning
  • Letters
  • Electromagnets
  • Meteorology
  • Domes
  • Electromagnetism


  • Document
  • Paper

ID Number

SIA2012-2926 and SIA2012-2927 and SIA2012-2928

Physical description

Number of Images: 3 ; Color: Color ; Size: 7 3/4w x 10h ; Type of Image: Document ; Medium: Paper

Full Record

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