| n. | 1. | (Chem.) An orthographic projection of the sphere on the plane of the meridian, the eye being supposed at an infinite distance, and in the east or west point of the horizon. |
| 2. | An instrument of wood or brass, on which this projection of the sphere is made, having a movable horizon or cursor; - formerly much used in solving some common astronomical problems. |
| 3. | A scale of the sun's declination for each day of the year, drawn across the torrid zone on an artificial terrestrial globe. |