(from Dutarte, Philippe Les instruments de l'astronomie ancienne de l'Antiquité à la Renaissance, Paris : vuibert, 2006, p. 55)
Armillary sphere, and a sense of the universe
The sphere from the "right" angle
Position of the universe at a certain time and place
(related to the position of the sun on the ecliptic, here at the summer solstice)
The armillary sphere and an equatorial sundial
(View from the meridian)
(the sundial was made by my student Rabbah Messaoudi)
(View from the meridian)
(the sundial was made by my student Rabbah Messaoudi)
View form the side
Conclusion
- Work with the armillary sphere and not with a two-dimensional geometrical figure
- Begin with an equatorial sundial (the natural starting point toward more complex sundials)
- Introduce 3D geometry
- Induce the need for geometry ...
Slide rule
Ozanam's text
Site :
http://www.taswegian.com/SRTP/JavaSlide/javaslide.html