Standard ATO wall regulator for industrial use

Beech and other hardwood. Case door is not original in my opinion.
Size: 18 inches high x 10 inches wide.

ATO battery electric type. Dial marked "ATO" and "Made in France"

References to this maker: CC has a brief history and pictures of some ATO clocks. The latest price guide booklet issued to complement the book gives a value of around £600 for these when in perfect condition.
A version of this clock for domestic use was also produced. It was very similar but had a smartly engraved backplate as seen here

In 1922 Marius Lavet, who had been closely associated with Favre-Bulle, published his notes on electrical timekeeping. In the same year Hatot produced prototypes of their battery electric clock based on M. Lavet's designs, and also in that year M. Lavet became a director of Etablissement Leon Hatot et Cie. Construction continued until at least 1948