WALFERDIN, François Hippolyte is born in 1795 in Langres in Haute-Marne. It was a Physicist. Employed customs, Walferdin is impassioned for physics, becomes the friend of Arago and Babinet and takes part in their work. It develops maximum and minimum thermometers, a hypsometer (which measure the altitude of a place by the boiling point of water) and a barometer to evaluate the depth in diving. It publishes also Complete Works of Diderot. In 1848, it is elected with the constituent Assembly. It was one of the founders of the Company of geology of France. It took an important and active share with the success of the drilling of the old well of Grenelle. It bequeathed to the museum of the Louvre the busts of Mirabeau and Diderot by Houdon. A street of its birthplace bears its name. François Walferdin died out in 1880 in Paris.Il rests in the 34e division.