The pendulum quadrant measures the elevation angles of celestial bodies, terrain points and buildings.
The quadrant is an astronomical instrument known since ancient Babylonian times. With the aid of a plumb line, it shows the angle between the lines of sight to a targeted point, e.g. a star, and the point on the horizon directly below it. This is referred to as the height or elevation angle of this point or star. Thanks to a transverse division of the scale, the measurement can be made to an accuracy of approx. 10 arc minutes. It is equipped with a sighting tube and handle. This simple instrument is the historical predecessor of the Jacob's staff and sextant.
How to measure: Determine any point in the sky (except the sun!) or in the landscape by sighting the point through the tube. Keep the plumb line on the quadrant. You can read the angle where the thread crosses the degree scale.
Never point the sighting tube directly at the sun! This can cause irreparable damage to your eyes! If you still want to determine the height of the sun, you can do so as follows: Point the right end of the sighting tube at the sun and hold the other end close to an inclined surface that catches the shadow of the quadrant, e.g. the palm of your hand. Then turn the quadrant until its shadow becomes a line and the sun can shine unobstructed through the sighting tube. The plumb line on the degree scale now indicates the angular height of the sun.
- Printed cardboard sheet for cutting out and assembling (A4)
- with detailed assembly instructions
- Size of the finished item: approx. 20 x 20 cm
