Photo: Henry Ulke (1821-1910), public domain, via Wikimedia Commons.
Joseph Henry was born in Albany in 1797 to a poor family. As a young man he worked and took classes at the Albany Academy, where he later became a teacher of mathematics and natural philosophy.
Work in Albany
At the academy in the late 1820s and early 1830s, Henry built powerful electromagnets by winding insulated wire in many layers. One of his magnets could lift hundreds of pounds. He also demonstrated a way to ring a bell at a distance using electromagnetism, an idea behind the telegraph.
He discovered self-induction, the effect of a changing current in a coil on itself. The scientific unit of inductance, the henry, is named for him.
Princeton and the Smithsonian
In 1832 Henry moved to the College of New Jersey, now Princeton. In 1846 he was chosen as the first Secretary of the Smithsonian Institution in Washington, a job he held until his death in 1878. He shaped it into a research institution and helped found the National Academy of Sciences.
A statue of Henry stands in front of the old Albany Academy building on Academy Park, where he did his early experiments.
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