Descartes, Compendium musicæ [D.20.52]
Demonstration of the numerical realationships between the three hexachords (or scales) as used by musicians in Descarte’s day.
![Descartes, Compendium musicæ [D.20.52]](https://photos.smugmug.com/Exhibitions/John-Smith-exhibtion/John-Smith-Gallery/i-wvjTpPB/0/82ed38a7/M/22-M.jpg)
![Apian’s Cosmographia [D.20.13]](https://photos.smugmug.com/Exhibitions/John-Smith-exhibtion/John-Smith-Gallery/i-2jDK2WS/0/5eb405ee/Ti/13-Ti.jpg)
![Diagram from Apian’s Cosmographia [D.20.13]](https://photos.smugmug.com/Exhibitions/John-Smith-exhibtion/John-Smith-Gallery/i-kcp29nS/0/3e668d6f/Ti/13a-Ti.jpg)
![Galileo Galilei (1564-1642). Il saggiatore: nel quale con bilancia esquisita e giusta si ponderano le cose contenute nella Libra Astronomica e Filosofica di Lotario Sarsi Sigensano. Rome, 1623. [D.20.15]](https://photos.smugmug.com/Exhibitions/John-Smith-exhibtion/John-Smith-Gallery/i-MQS45n6/0/1b59d4c7/Ti/14-Ti.jpg)
![Galileo Galilei (1564-1642). Il saggiatore: nel quale con bilancia esquisita e giusta si ponderano le cose contenute nella Libra Astronomica e Filosofica di Lotario Sarsi Sigensano. Rome, 1623. [D.20.15]](https://photos.smugmug.com/Exhibitions/John-Smith-exhibtion/John-Smith-Gallery/i-JLSQWWq/0/73efc7e2/Ti/15-Ti.jpg)
![Joseph Justus Scaliger(1540-1609). Cyclometrica Elementa Duo. [Elements of Circle Measurement]. Leiden, 1594. [D.1.30]](https://photos.smugmug.com/Exhibitions/John-Smith-exhibtion/John-Smith-Gallery/i-prxp5vn/0/92334a30/Ti/16-Ti.jpg)
![Scaliger's Cyclometrica Elementa Duo. [D.1.30]](https://photos.smugmug.com/Exhibitions/John-Smith-exhibtion/John-Smith-Gallery/i-RxL6NZ2/0/e05a7ec1/Ti/17-Ti.jpg)
![Marin Mersenne (1588-1648). Harmonicorum Libri III, Graece et Latinei. Paris, 1636. [D.1.17]](https://photos.smugmug.com/Exhibitions/John-Smith-exhibtion/John-Smith-Gallery/i-8fFJMVX/0/2c628ded/Ti/19-Ti.jpg)
![Mersenne, Harmonicorum Libri [D.1.17]](https://photos.smugmug.com/Exhibitions/John-Smith-exhibtion/John-Smith-Gallery/i-WcFWxrg/0/5f569e69/Ti/20-Ti.jpg)
![Rene Descartes (1596-1650). Compendium musicæ. Utrecht, 1640. [D.20.52]](https://photos.smugmug.com/Exhibitions/John-Smith-exhibtion/John-Smith-Gallery/i-9sghT9M/0/70f0564e/Ti/21-Ti.jpg)
![Descartes, Compendium musicæ [D.20.52]](https://photos.smugmug.com/Exhibitions/John-Smith-exhibtion/John-Smith-Gallery/i-wvjTpPB/0/82ed38a7/Ti/22-Ti.jpg)
![Johannes Kepler (1571-1630). Harmonices mundi [Harmony of the World], Linz, Austria, 1619. [D.1.9]](https://photos.smugmug.com/Exhibitions/John-Smith-exhibtion/John-Smith-Gallery/i-j77q5fM/0/7ec40a85/Ti/23-Ti.jpg)