Cut a piece of black paper or foam that’s the length of the triangular prism tube and wide enough to wrap around it completely, with a little overlap. Glue or tape this black backing around the tube to create the mirrors.
Measure and cut the pencil to the length of the prism tube plus enough to let the eraser hang over the edge. You can cut through the pencil with an X-Acto, a utility knife, or a small saw. Make sure the cut end is smooth.
Use electrical, cloth, or foam tape to tape the pencil tightly to the middle of one of the flat sides of the tube, running parallel along the outside.
Glue beads and treasures to the yogurt lid with craft glue. Allow the glue to dry overnight. It will dry clear, so don’t be stingy; make sure everything is glued securely.
Stick the pushpin or thumbtack through the center of the decorated lid and anchor it into the middle of the pencil eraser.
That’s it. Spin the disk and look through the tube to a beautiful image! Making this kaleidoscope unlocks the principles of how the instrument works. Learn more about all things kaleidoscopic at http://www.brewstersociety.com.