- The instrument which is employed to directly measure the tri-stimulus coordinates of a color is known as a colorimeter .
- An input device that provides coordinates of a position . example : a mouse , a tablet
- We will talk more about the celestial sphere and how to tell the positions of the stars in the sky . we will also introduce the constellations and the star atlas
- Declination of a planet is his distance from the equator , and as he declines from thence either northward or southward , so is his declination nominated either north or south