![Watch ca. 1650–60 Watchmaker: Jean Rousseau Constantijn Huygens wrote to his brother, the brilliant mathematician Christiaan Huygens, from Geneva on January 5, 1650, that he had just bought a watch "á la Watch ca. 1650–60 Watchmaker: Jean Rousseau Constantijn Huygens wrote to his brother, the brilliant mathematician Christiaan Huygens, from Geneva on January 5, 1650, that he had just bought a watch "á la](https://c8.alamy.com/comp/2HHT36B/watch-ca-165060-watchmaker-jean-rousseau-constantijn-huygens-wrote-to-his-brother-the-brilliant-mathematician-christiaan-huygens-from-geneva-on-january-5-1650-that-he-had-just-bought-a-watch-la-mode-with-a-case-of-rock-crystal-that-permitted-a-view-of-the-movement-such-as-one-would-see-if-the-case-were-made-of-ice-indeed-geneva-was-well-known-for-its-rock-crystal-watchcases-made-from-a-local-source-of-the-mineral-the-movement-of-this-watch-has-a-verge-escapement-and-it-is-probably-the-product-of-the-younger-jean-rousseau-a-son-of-a-master-clockmaker-in-geneva-and-the-great-gran-2HHT36B.jpg)
Watch ca. 1650–60 Watchmaker: Jean Rousseau Constantijn Huygens wrote to his brother, the brilliant mathematician Christiaan Huygens, from Geneva on January 5, 1650, that he had just bought a watch "á la
![Two designs for levels, on the right (fig. 14) by Jean Picard and on the left (fig. 13) by Christiaan Huygens] / JM [or TM] sc 1768 Stock Photo - Alamy Two designs for levels, on the right (fig. 14) by Jean Picard and on the left (fig. 13) by Christiaan Huygens] / JM [or TM] sc 1768 Stock Photo - Alamy](https://c8.alamy.com/comp/2A4H2TK/two-designs-for-levels-on-the-right-fig-14-by-jean-picard-and-on-the-left-fig-13-by-christiaan-huygens-jm-or-tm-sc-1768-2A4H2TK.jpg)
Two designs for levels, on the right (fig. 14) by Jean Picard and on the left (fig. 13) by Christiaan Huygens] / JM [or TM] sc 1768 Stock Photo - Alamy
![Jean-Marc Huygen, architecte enseignant, auteur de La poubelle et l'architecte (Actes Sud) « Le réemploi nécessite un savoir-faire dans la manière "d'ensembler" des objets et matériaux très divers » Jean-Marc Huygen, architecte enseignant, auteur de La poubelle et l'architecte (Actes Sud) « Le réemploi nécessite un savoir-faire dans la manière "d'ensembler" des objets et matériaux très divers »](https://www.amc-archi.com/mediatheque/3/4/3/000259343/photo-070-image55343-jpg.jpg)