The Instrument DBS Equation Sidereal is a tribute to two watches (Nos. 1 and 2) made by John Roger Arnold that showed mean solar and sidereal time on two separate subdials. The movements of these two watches, made between 1796 and 1799, featured some of the most famous inventions of father and son, including their fabulous thermo-compensated Z balance, expansion escapement and gold helical spring. It is no exaggeration to say that they represented the state of the art in the micromechanics of their time.
Functions Local hours, minutes and seconds, sidereal hours and minutes, local time 24 h indicator, sidereal time 24 h indicator
Caliber A&S1311 Exclusive Arnold & Son mechanical movement, hand-wound, 42 jewels, diameter 35 mm, thickness 3.9 mm, power reserve 40 h, 21'600 vibrations /h. Movement decoration: Nickel-silver movement, rhodium treated with Haute Horlogerie finishing: manually chamfered bridges and polished edges, fine circular graining and 'Côtes de Genève', blued screws.
18-Carat Rose Gold, diameter 44mm, cambered sapphire with anti-reflective coating on both sides, case back see-through sapphire