Diane France - Casting for Clues

	www.iwaswondering.org © 2005 National Academy of Sciences
PRINT THE CASTING DATA SHEET TOO! You also need to print the Casting Data Sheet for a full set of Science Lab instructions.

Forensic anthropologist Diane France has made casts of human brains, the bones of outlaw Jesse James, and even a tiger's tongue and paws. Diane uses these casts to help solve mysteries and crimes, or sometimes for educational purposes. She knows that every cast has a story to tell!

In this activity, you are going to make casts and figure out a mystery, too. First, you and your friends will make face casts with papier-mâché. Then you'll study the dimensions of the masks to match each mask to a person.

This activity gets messy, so make sure you are wearing old clothes and leave plenty of time to dry the mask and clean up!


	1 old newspaper Flour ~ 1.5 cups per person Water ~ 2 cups per person Large mixing bowl Petroleum jelly Paint Tape measure, or ruler and string (1 foot) One or more fellow scientists Old shirts or towels you can mess up Hair dryer Straws Aluminum foil Paint, markers, and other art supplies for decorating the masks Casting Data Sheet Casting Journal

1. Invite some fellow scientists over. 2. Print the Casting Data Sheet.

If you have more than one friend, print out additional data sheets.

3. Measure each person's face.

Start by measuring each person's face with your tape measure before you make the cast. (The Casting Data Sheet tells you what to measure.) Write down the measurements in the Casting Data Sheet.

4. Decide who will be the caster first and who will be the model first.

You will take turns until each person's face has been cast.

5. Prepare your materials.

Tear long newspaper strips that are about 1 or 2 inches wide. Put them aside. In a mixing bowl, mix enough water and flour for one person until it looks like yogurt. Mix well to get out all the bumps! Add more flour if the mixture is too watery or add more water if it is too thick. You've just made papier-mâché!

6. Put petroleum jelly all over the model's face.

The petroleum jelly will allow you to get the papier-mâché off when it dries, so make sure to get it close to the model's hairline. Wash your hands well when you're finished.

7. Cast the model's face.

Dip a strip of newspaper into the bowl. Use your index finger and middle finger to act like a squeegee to run down the strip of paper so it's not totally soaked. Then place the strip of newspaper on your model's face, crisscrossing to make overlapping layers. Follow the contours of the face and smooth, leaving no bumps or ridges.

Make sure you have breathing holes when applying the papier-mâché. Give the model straws for her mouth and nose to breathe through. Make sure there is an adult nearby if you need help.

To keep the papier-mâché from falling off, the model should lean back in a chair. Keep very still. Laughing crumples the papier-mâché!

8. Let the papier-mâché dry.

Use a hair dryer for about 45 minutes (depending on how many layers you made and how wet it is) to speed dry the mask, but keep it about 10-12 inches away from the model's face. Use the low and cool setting. When the mask is mostly dry, peel it off. Then place the mask on crunched-up aluminum foil, so it will keep its shape as it dries completely.

9. Finish all the casts.

Repeat the process for each of your fellow scientists. When all the casts are complete, put them in a safe place and let them dry overnight.

10. Mix up the masks and label them.

Someone should secretly mark the masks 1, 2, 3, etc. Using a separate sheet of paper, write down which mask belongs to which scientist. Mix up the masks so you don't know whose mask is whose.

11. Measure the masks.

Measure the dimensions of each mask. Record the mask measurements on the Casting Data Sheet. Then see if you can identify whose face belongs to each numbered mask. Check with the labels to see if you are right!

12. Analyze the Data.

Print your Casting Journal. Write down some of the things you learned as you made the face casts.

13. Decorate your masks.

Use white paint for your first coat so the newspaper writing doesn't show through. When you're finished, hang up the masks, or invite your friends to a masquerade party!

The Science of Casting

Scientists cast things as a way to create scientific models for many reasons:

Casting models allows people to explore something they normally could not.

Diane France cast a model of a tiger's tongue for the National Zoo because it would be too dangerous for people to touch a real one (ouch!).

Casting models documents history.

Compare a cast of your face at age 11 with your face at age 14. You'll probably find some big differences.

When a scientist finishes an experiment, she writes up her notes and analyzes her data. Write your analysis here, starting with a few simple questions. Diane's casts tell a story. What stories do your masks tell?

How well were you able to identify the masks by using the measurements?

How does your cast compare to your model's actual face?

Are the measurements the same, close, or very different?

What might have caused the difference?

What is the most interesting thing you observed?

Did anything you learn surprise you? Write it down here.

Would your next-door neighbor know that the cast you made was of your face? What else could you do to make your cast look better?