Amazing Art Deco Egyptian French Mantel clock by the electric clock manufacturer ATO of Besançon, France. Emerald Onix from Brasil over black Belgian marble body with square chromed bezel and highly stylized face. Stunning combinationof green and black colors Battery Operated París.. Founded in 1920 by Léon Hatot, ATO was the first known clock manufacturer to experiment with different operating methods and unusual materials. A very refined and unique 1930s art deco clock of Belgian black marble