 He was the author of several valuable publications on the art and science of clock-making and chronography, among them the "Étrennes chronométriques" of 1760.He also became "Horloger du Roi" in 1760.The work of Le Roy was not fully recognized in France however, and his contemporary Ferdinand Berthoud became more famous, obtaining the prestigious title of "Horloger de Marine", which left Le Roy disillusioned and led him to retire.