Earth's rotation Foucault in 1851, which consisted of a lead-filled brass sphere suspended from the top of the Panthéon in Paris. Because of the Earth's rotation under the swinging pendulum, the pendulum's plane of oscillation appears to rotate at a rate depending on latitude. At the latitude of Paris the predicted and observed shift was about clockwise per hour. Foucault pendulums now swing in museums around the world. Earth's rotation period relative to the Sun (solar noon to solar noon) is its "true solar day" or "apparent solar day". It depends on the Earth's orbital motion and is thus affected by changes
Pierre-François-Victor Foucault Société d'encouragement pour l'industrie nationale, then he showed it at The Great Exhibition (1851) in London. Pierre-François-Victor Foucault Pierre-François-Victor Foucault (1797-1871) was the inventor in 1843 of the first printing machine for braille, the . A pupil of the Institut National des Jeunes Aveugles, Foucault married Thérèse-Adèle Husson, a blind author, in 1826. This marriage gave birth to two daughters. After his wife's death in 1831, following a fire, he married a seamstress (non blind) in 1832, Adélaïde Louise Juteau. This allowed him to become a resident of the Quinze-Vingts (marriages between blind people were prohibited), which gave him the