Small Museums of Paris

I know we're tilting towards walking and eating and forgetting the monumental museums (ie, the Louvre) but I'm working my way through Edmund White's The Flaneur and he's telling me that "Paris has countless small and bizarre museums, little corners where someone's bid for immortality goes unnoticed - one might say a neglected shrine to a forgotten god.  Or sometimes the museum caters to a perfectly real and valid taste, but one not shared by too many people." 
And I figure we'll be stumbling on a number of these, even if we never get out of the Rive Gauche.  And we might nip in and take a look especially if the admission is free.  Par example there is Musee Nissim de Camodo which is mentioned in a Gourmet travel article:

"Facing the Parc Monceau, the Musée Nissim de Camondo is one of the most engaging and poignant of the city’s small museums. Built just before World War I by Moïse de Camondo, scion of a family known as the Rothschilds of the East, the house was designed to showcase his antiques. And after admiring the dazzling silver tureens made for Catherine the Great, wander through the spacious, bright kitchens. Restored to an as-built state, the fittings include remarkably modern water purifiers and a copper sink with a steam jacket to keep dishwashing water hot. And the vast stove, with separate ovens and a rotisserie, still inspires envy".

Now in The Flaneur, White has just spent part of a chapter on Jews in Paris on the Camondo family and tells us that all the family were killed at Auschwitz.  "The Camondos, who had contributed so much to the cultural life of France, had been extinguished, and the French authorities had done nothing to save them."

But, to lighten up, there are a number of other museums we might duck into especially the Musee des Arts et Mettiers:
Founded in 1794 and today occupying the former priory of Saint-Martin-des-Champs, the offbeat Musée des Arts et Metiers is devoted to scientific discovery and mechanical and industrial inventions, which are organized according to seven themes: scientific instruments, materials, construction, communication, mechanics, energy, and transport. Perhaps the most famous instrument in its collection of some 80,000 objects is Foucault’s pendulum, which was popularized by a novel by Italian writer Umberto Eco.
60 rue Réaumur; 3rd
Do you think Fernando might enjoy this one?