by David Colarusso - April 3rd, 2007
The quadrant is a simple tool for measuring the altitude (angle) of an object above the horizon. This episode makes use of a printable template found at: http://www.davidcolarusso.com/handouts/quadrant.pdf
The Tabletop Explainer
Episode Seven (7)
How to Build a Paper Quadrant
Start by visiting http://www.davidcolarusso.com and downloading the PDF document located at slash handouts slash quadrant dot PDF. Print out this document, and simply follow the instructions.
To find the altitude of an object, point the business end of the quadrant straight at it. Then read the number under the string. Usually you can do this by looking through the straw and aming. For the Sun, however, do NOT do this. Instead take something and hold it behind the quadrant. When the Sun is properly sighted, the rays of light from the Sun will be traveling parallel to the straw. This will cause the straw to cast a circular shadow as the Sun’s rays travel straight down the center.
Good… Bad… Good. Then simply read the altitude.
What do you think?
Now that you have a quadrant, what can you use it for?
Why don’t you try measuring the altitude of celestial objects over the course of several days?