- Title: Démonstrations Géométriques, des Sphères Droite, Paralelle, et Oblique
- Author: Louis Brion de la Tour
- Date: c. 1770
- Medium: Hand-colored copperplate engraving
- Condition: Very Good - foxing and age toning, paper loss in left margin, tide marks in lower corners
- Inches: 14 1/8 x 11 1/8 [Paper]
- Centimeters: 35.88 x 28.26 [Paper]
- Product ID: 102029
"Geometric Demonstrations of Straight, Parallel, and Oblique Spheres"
Image depicting the axes of the earth as viewed from different perspectives. Includes a compass rose at center and a diagram of the refraction of sunlight.