March 7, Another post from the Washington trip. This statue is located in front of the Smithsonian Castle. It is Joseph Henry (17 December 1797 – 13 May 1878). He was an American scientist who served as the first Secretary of the Smithsonian Institution, as well as a founding member of the National Institute for the Promotion of Science, a precursor of the Smithsonian Institution. The SI unit of inductance, the henry, is named in his honor, as are derivative units such as the millihenry and microhenry. Henry's work on the electromagnetic relay was the basis of the electrical telegraph, invented by Samuel Morse and Charles Wheatstone separately.