First-Class Chronometer Tourbillon” Girard-Perregaux

“First-Class Chronometer Tourbillon” Girard-Perregaux, Chaux-de-Fonds, No. 83998. Made in 1877. Very fine and very rare 18K rose gold, hunting-cased, keyless pocket chronometer, with one-minute Guinand type II tourbillon regulator and pivoted spring detent escapement. Four-body, massive "bassine et filets", engine-turned, the cover centered with a monogram, engraved hinged gold cuvette, the interior with engine-turned decoration, glazed gold-rimmed cover to view the movement. White enamel with painted radial Roman numerals, outer five minute Arabic numerals and minute markers and subsidiary seconds. Blued steel pierced "tulip" hands. Notes Ernest Guinand (c. 1810-1879). Guinand was an important Master Horologist from Le Locle, who, along with Auguste Grether from Ponts-de-Martel (1817-1879), specialized in the production of tourbillon carriages. According to the records of the Neuchâtel Observatory, Guinand's production of tourbillons began between 1865 and 1867. He designed three models of Tourbillon carriages, always based on an A-shaped frame. He worked for several important makers, including Girard-Perregaux and Montandon. Most of Guinand’s carriages were equipped with a pivoted detent escapement, one with spring detent and some with lever escapement. Most of his carriages were not signed and can only be identified by their characteristic A-shape. In 1864 Patek Philippe chose him to build their first tourbillon regulator.