1. Glue the drawing above to a piece of manila folder. Cut around the dashed lines.
  2. Fold the top section over a pencil and roll it down to the dotted line to make a sighting tube.
  3. Tape the rolled paper tube and then let the pencil slide out.
  4. Take about 10 inches of string and tie one end to a weight (rubber hose washers work well as do small rubber stoppers). Tie the other end through the hole indicated on the drawing.
  5. Let the string hang free. The angle it marks off is the angular height of an object seen through the tube.
  6. This device can be used for measuring heights and as a horizontal accelerometer.