Tracking The Phases Of The Moon
Aprilk13
ASTROLABE.docxTHE ASTROLABE – MAKING A SIMPLE ALTITUDE-FINDING DEVICE
The ASTROLABE was invented in Greece by either Hipparchus, a 2nd Century BC astronomer, or Apollonius of Perga, a 3rd Century BC mathematician. For many centuries, it was used by both astronomers and navigators, and especially by the 15th century AD explorers who used it to determine latitude, longitude, and time of day.
Supplies required:
· File folder or protractor cut-out copied on card stock
· Drinking Straw
· Dark string or strong thread
· Washer
· Glue (to glue protractor cut-out to file folder)
· Transparent tape
· Scissors
· Hole punch (optional)
Directions:
1. Print out a copy of the protractor, on the following page.
2. Glue the copy of the protractor to file folder. Cut the protractor out with scissors.
3. Using scissors or a hole-punch, carefully make a small notch at each of the lines marked along the curved edge of the cardboard-mounted protractor. These notches will come in handy when you're measuring the angle between two celestial objects and you have to hold the device horizontally.
4. Cut a drinking straw to the same length as the sides of the device as indicated.
5. Tape the drinking straw to the edge of the device marked “attach straw to this edge.” Be careful to not tape the straw on the astrolabe, but just on the edge.
6. Carefully poke a small hole through the device where the "!" is marked, pass the string through it, and knot the string at the back of the cardboard or tape it there.
7. Tie the washer to the opposite (front) end of the string as shown.
The finished altitude-finder, called an Astrolabe
PROTRACTOR CUT-OUT FOR THE ASTROLABE
Small Hole "" Carefully poke a small hole at this point. Be careful not to oversize the hole or ‘poke’
"NOTE: Print this on card stock, or glue to a file folder and then cut out the protractor.
