Leroy Chronomètre Observatoire Osmior
This timepiece is a reference to the inventions of the 18th century master-watchmakers and features the fundamental principles of horological science, inspired by the work of Pierre Le Roy (1717–1785), “the father of modern chronometry”.
Heir to an exceptional historical heritage spanning more than 300 years, Leroy has set itself the challenge of reviving through various contemporary reinterpretations the fundamental codes of the spirit that has inspired it since its founding in 1713.
The Chronomètre Observatoire is equipped with the new-generation hand-wound L200 movement entirely developed and built in Leroy's Manufacture in Le Sentier (Switzerland) and equipped with an escapement with direct impulse on the balance, balance-spring with double terminal curve and parallel-mounted twin barrels. The calibre oscillates at a rate of 18,000 vph (2.5 Hz) and includes 42 jewels including four synthetic diamond jewels.
The movement is housed within a round gold case (5N red gold, white gold or two-tone 950 palladium and 5N red gold) with a 38 or 40 mm diameter, framing a refined solid silver dial adorned with hand-guilloché “barleycorn” motifs inspired by 19th century Leroya pocket watches.
The applied Arabic numerals are made of gold and delicately cabochonné, meaning each is hand-polished and domed.
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The Chronomètre Observatoire model provides a central display of the hours and minutes via cut-out “Corteault” shaped steel hands and also features the stop-seconds function.
A small subdial at 6 o’clock shows the passing of the seconds by means of a “duplex” jump (thus named in tribute to Pierre Le Roy and his Duplex escapement) consisting in a short jump followed by a longer one. A lozenge-shaped aperture at 9 o’clock reveals the disc providing the 98-hour power-reserve indication.
The dials come in a choice of five colours: opaline silver-toned, Leroy blue, Leroy champagne, rosé champagne and slate grey. The hour-markers match the colour of the gold case, while the blue, rhodiumed or “black gold” hands may be selected according to the customer’s personal preferences.
The movement wheels are produced and adorned in keeping with the highest quality standards. The pinion leaves are polished using a wooden grinding wheel and the ratchet-wheels finished using the ”Mât de Genève” (Geneva Mast) process, an ancient decorative technique that give them an anthracite colour, while the other steel parts as well as the winding mechanism are specular polished. The bridges are bevelled and frosted to create a bronze-tone colour. All the screws are blued from the outset to avoid oxidation, while the screw heads are specular-polished and even the profiles of the collets are also polished.
The timepiece is tamed with a hand-sewn alcantara-lined alligator leather strap secured by a pin buckle or folding clasp.
Each Chronomètre Observatoire watch is individually numbered and delivered with its own chronometer rating certificate issued by Besançon Observatory.