SB10 Jumping Hour 250th Anniversary

For its tenth anniversary, French independent Sartory-Billard introduces the SB10 Jumping Hour, its first complication, in a limited edition marking the 250th anniversary of the United States. The watch distills the ideas behind the SB08 concept of 2024: a large, instantly legible hour display, a fluid reading of the minutes, and a central surface freed entirely from the traditional dial. In place of that dial sits a cabochon, mounted from the outside like a stone set into the case.

For the SB10 250th Anniversary, the cabochon is American copper, the metal that gave the Statue of Liberty its blue-green patina. Ron Elkins CNC engraves each one in the United States with a guilloché pattern inspired by the American flag in motion, Chris Alexander of The Dial Artist hand patinates the copper in Scotland to accelerate decades of oxidation, and Armand Billard assembles the watch in France. The cabochon sits fully exposed and is meant to be touched; contact slowly wears the protective lacquer, the copper keeps oxidizing, and no two examples will age alike.

There are no hands. The hour appears in a wide aperture at six o’clock on a sapphire disc about 0.2 mm thick, jumping instantly on the hour, with oversized numerals drawn by typographer Simon Schmidt. A second sapphire disc rotates once an hour, its red marker tracing the minutes along a ring of Super-LumiNova BGW9 that glows turquoise after dark. The automatic La Joux-Perret G101A caliber with a patented jumping hour module runs inside a 39.5 mm stainless steel case.