Boule de Genève The “Boule de Genève” watches incorporate a double-plan movement and the revolving bezel winding system patented by Marius Lecoultre (1847-1915) of Geneva (Swiss invention patent No. 114, dated January, 12, 1889). He was the son of Eugène Lecoultre (1819-1882), Genevan watchmaker who invented the perpetual calendar with rétrograde (fly-back) date (circa 1850). The majority of the “Boule de Genève” is manufactured with an 8’’’ movement (with cylinder or lateral lever escapement). It can sometimes be found with smaller movements, 7’’’ or 6’’’ and very occasionally with a movement of 5’’’. The realisation of this movement is already in itself a technical feat but to execute it in such a small dimension is a real “tour de force”. Some of these movements were inserted into brooches or bracelets by the best jewellers of Geneva; they also often subcontractors of the great manufactures. If the majority of them are unsigned, some have been bought or possibly produced by major Genevan manufactures such as Patek Philippe, who presents one during the World’s Columbian Exposition in Chicago in 1893. Later Cartier, Paris, also produces “Boule de Genève”-type watches.