Sphere Armillaire du Lycee Henri IV a Paris - Armillary sphere. Henri IV school, Paris...

Sphere Armillaire du Lycee Henri IV a Paris - Armillary sphere. Henri IV school, Paris - Sphere armillaire set up in the courtyard of the Meridian of Lycee Henri IV, in Paris. It dates back to 1850. It is composed of two circular iron rings, one vertical, in the plane of the Meridian, the other, graded, in the plane of the Equator. A long metal stem crosses diametrally the Meridian circle, representing the axis of the poles. The shadow projected by the axis of the poles on the inner edge of the equatorial circle allows us to know the moment of the passage from the Sun to the local meridian (true midday). Armillary sphere of 1850 in Lycee Henri IV, Paris